Merge pull request #861 from apache/feature/WW-5388-upload-servlet6

[WW-5388] Uses the latest JakartaEE FileUpload Servlet 6 package

apps/showcase/src/main/java/org/apache/struts2/showcase/fileupload/FileUploadAction.java

@@ -24,6 +24,7 @@ import com.opensymphony.xwork2.ActionSupport;
 import org.apache.struts2.action.UploadedFilesAware;
 import org.apache.struts2.dispatcher.multipart.UploadedFile;
 
+import java.io.File;
 import java.util.List;
 
 /**
@@ -32,7 +33,7 @@ import java.util.List;
 public class FileUploadAction extends ActionSupport implements UploadedFilesAware {
 
     private String contentType;
-    private UploadedFile uploadedFile;
+    private UploadedFile<File> uploadedFile;
     private String fileName;
     private String caption;
     private String originalName;
@@ -78,7 +79,7 @@ public class FileUploadAction extends ActionSupport implements UploadedFilesAwar
     }
 
     @Override
-    public void withUploadedFiles(List<UploadedFile> uploadedFiles) {
+    public void withUploadedFiles(List<UploadedFile<File>> uploadedFiles) {
         this.uploadedFile = uploadedFiles.get(0);
         this.fileName = uploadedFile.getName();
         this.contentType = uploadedFile.getContentType();

apps/showcase/src/main/resources/struts-fileupload.xml

@@ -24,6 +24,9 @@
 	"https://struts.apache.org/dtds/struts-6.0.dtd">
 
 <struts>
+
+	<constant name="struts.multipart.maxSize" value="10240" />
+
 	<package name="fileupload" extends="struts-default" namespace="/fileupload">
 
         <action name="upload" class="org.apache.struts2.showcase.fileupload.FileUploadAction" method="input">

apps/showcase/src/main/webapp/WEB-INF/fileupload/upload-success.jsp

@@ -41,7 +41,8 @@
 		        <li>FileName: <s:property value="fileName" /></li>
 		        <li>Original FileName: <s:property value="originalName" /></li>
 		        <li>File: <s:property value="uploadedFile" /></li>
-		        <li>Caption:<s:property value="caption" /></li>
+				<li>Size: <s:property value="uploadSize" /></li>
+				<li>Caption: <s:property value="caption" /></li>
 	        </ul>
 		</div>
 	</div>

apps/showcase/src/test/java/it/org/apache/struts2/showcase/FileUploadTest.java

@@ -18,9 +18,6 @@
  */
 package it.org.apache.struts2.showcase;
 
-import java.io.File;
-import java.io.FileWriter;
-
 import org.htmlunit.WebClient;
 import org.htmlunit.html.HtmlFileInput;
 import org.htmlunit.html.HtmlForm;
@@ -29,6 +26,10 @@ import org.htmlunit.html.HtmlPage;
 import org.htmlunit.html.HtmlSubmitInput;
 import org.junit.Test;
 
+import java.io.File;
+import java.io.FileWriter;
+import java.security.SecureRandom;
+
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class FileUploadTest {
@@ -46,6 +47,42 @@ public class FileUploadTest {
 
             try (FileWriter writer = new FileWriter(tempFile)) {
                 writer.append("Some strings");
+                writer.flush();
+            }
+
+            uploadInput.setValue(tempFile.getAbsolutePath());
+            final HtmlSubmitInput button = form.getInputByValue("Submit");
+            final HtmlPage resultPage = button.click();
+
+            String content = resultPage.getVisibleText();
+            assertThat(content).contains(
+                    "ContentType: text/plain",
+                    "Original FileName: " + tempFile.getName(),
+                    "Caption: some caption",
+                    "Size: 12"
+            );
+        }
+    }
+
+    @Test
+    public void testUploadOverMaxSize() throws Exception {
+        try (final WebClient webClient = new WebClient()) {
+            final HtmlPage page = webClient.getPage(ParameterUtils.getBaseUrl() + "/fileupload/doUpload.action");
+            final HtmlForm form = page.getFormByName("doUpload");
+            HtmlInput captionInput = form.getInputByName("caption");
+            HtmlFileInput uploadInput = form.getInputByName("upload");
+
+            captionInput.type("Large file");
+
+            File tempFile = File.createTempFile("testEmptyFile", ".txt");
+            SecureRandom rng = new SecureRandom();
+            tempFile.deleteOnExit();
+            try (FileWriter writer = new FileWriter(tempFile)) {
+                for (int i = 0; i < 10240; ++i) {
+                    String line = String.format("%s %s%n", rng.nextInt(), rng.nextInt());
+                    writer.append(line);
+                }
+                writer.flush();
             }
 
             uploadInput.setValue(tempFile.getAbsolutePath());
@@ -55,9 +92,7 @@ public class FileUploadTest {
             String content = resultPage.getVisibleText();
             System.out.println(content);
             assertThat(content).contains(
-                    "ContentType: text/plain",
-                    "Original FileName: " + tempFile.getName(),
-                    "Caption:some caption"
+                    "Request exceeded allowed size limit! Max size allowed is: 10,240!"
             );
         }
     }

core/pom.xml

@@ -19,7 +19,8 @@
  * under the License.
  */
 -->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <parent>
         <groupId>org.apache.struts</groupId>
@@ -216,8 +217,7 @@
         <!-- File upload -->
         <dependency>
             <groupId>org.apache.commons</groupId>
-            <artifactId>commons-fileupload2-jakarta</artifactId>
-            <version>2.0.0-M1</version>
+            <artifactId>commons-fileupload2-jakarta-servlet6</artifactId>
         </dependency>
         <dependency>
             <groupId>commons-io</groupId>

core/src/main/java/org/apache/struts2/StrutsConstants.java

@@ -140,21 +140,28 @@ public final class StrutsConstants {
     public static final String STRUTS_UI_ESCAPE_HTML_BODY = "struts.ui.escapeHtmlBody";
 
     /** The maximum size of a multipart request (file upload) */
-    public static final String STRUTS_MULTIPART_MAXSIZE = "struts.multipart.maxSize";
+    public static final String STRUTS_MULTIPART_MAX_SIZE = "struts.multipart.maxSize";
+
+    /** The maximum size of all uploaded files.
+       Used only with {@link org.apache.struts2.dispatcher.multipart.JakartaStreamMultiPartRequest} */
+    public static final String STRUTS_MULTIPART_MAX_SIZE_OF_FILES = "struts.multipart.maxSizeOfFiles";
 
     /** The maximum number of files allowed in a multipart request */
-    public static final String STRUTS_MULTIPART_MAXFILES = "struts.multipart.maxFiles";
+    public static final String STRUTS_MULTIPART_MAX_FILES = "struts.multipart.maxFiles";
 
     /** The maximum length of a string parameter in a multipart request. */
     public static final String STRUTS_MULTIPART_MAX_STRING_LENGTH = "struts.multipart.maxStringLength";
 
     /** The maximum size per file in a multipart request */
-    public static final String STRUTS_MULTIPART_MAXFILESIZE = "struts.multipart.maxFileSize";
-    /** The directory to use for storing uploaded files */
-    public static final String STRUTS_MULTIPART_SAVEDIR = "struts.multipart.saveDir";
+    public static final String STRUTS_MULTIPART_MAX_FILE_SIZE = "struts.multipart.maxFileSize";
 
-    /** Declares the buffer size to be used during streaming multipart content to disk. Used only with {@link org.apache.struts2.dispatcher.multipart.JakartaStreamMultiPartRequest} */
-    public static final String STRUTS_MULTIPART_BUFFERSIZE = "struts.multipart.bufferSize";
+    /** The directory to use for storing uploaded files */
+    public static final String STRUTS_MULTIPART_SAVE_DIR = "struts.multipart.saveDir";
+
+    /** Declares the buffer size to be used during streaming multipart content to disk.
+     * Used only with {@link org.apache.struts2.dispatcher.multipart.JakartaStreamMultiPartRequest}
+     */
+    public static final String STRUTS_MULTIPART_BUFFER_SIZE = "struts.multipart.bufferSize";
 
     /**
      * The org.apache.struts2.dispatcher.multipart.MultiPartRequest parser implementation

core/src/main/java/org/apache/struts2/action/UploadedFilesAware.java

@@ -20,6 +20,7 @@ package org.apache.struts2.action;
 
 import org.apache.struts2.dispatcher.multipart.UploadedFile;
 
+import java.io.File;
 import java.util.List;
 
 /**
@@ -35,6 +36,6 @@ public interface UploadedFilesAware {
      *
      * @param uploadedFiles a list of {@link UploadedFile}, cannot be null. It can be empty.
      */
-    void withUploadedFiles(List<UploadedFile> uploadedFiles);
+    void withUploadedFiles(List<UploadedFile<File>> uploadedFiles);
 
 }

core/src/main/java/org/apache/struts2/config/entities/ConstantConfig.java

@@ -199,12 +199,12 @@ public class ConstantConfig {
         map.put(StrutsConstants.STRUTS_UI_TEMPLATEDIR, uiTemplateDir);
         map.put(StrutsConstants.STRUTS_UI_THEME, uiTheme);
         map.put(StrutsConstants.STRUTS_UI_THEME_EXPANSION_TOKEN, uiThemeExpansionToken);
-        map.put(StrutsConstants.STRUTS_MULTIPART_MAXSIZE, Objects.toString(multipartMaxSize, null));
-        map.put(StrutsConstants.STRUTS_MULTIPART_MAXFILES, Objects.toString(multipartMaxFiles, null));
-        map.put(StrutsConstants.STRUTS_MULTIPART_MAXFILESIZE, Objects.toString(multipartMaxFileSize, null));
+        map.put(StrutsConstants.STRUTS_MULTIPART_MAX_SIZE, Objects.toString(multipartMaxSize, null));
+        map.put(StrutsConstants.STRUTS_MULTIPART_MAX_FILES, Objects.toString(multipartMaxFiles, null));
+        map.put(StrutsConstants.STRUTS_MULTIPART_MAX_FILE_SIZE, Objects.toString(multipartMaxFileSize, null));
         map.put(StrutsConstants.STRUTS_MULTIPART_MAX_STRING_LENGTH, Objects.toString(multipartMaxStringLength, null));
-        map.put(StrutsConstants.STRUTS_MULTIPART_SAVEDIR, multipartSaveDir);
-        map.put(StrutsConstants.STRUTS_MULTIPART_BUFFERSIZE, Objects.toString(multipartBufferSize, null));
+        map.put(StrutsConstants.STRUTS_MULTIPART_SAVE_DIR, multipartSaveDir);
+        map.put(StrutsConstants.STRUTS_MULTIPART_BUFFER_SIZE, Objects.toString(multipartBufferSize, null));
         map.put(StrutsConstants.STRUTS_MULTIPART_PARSER, beanConfToString(multipartParser));
         map.put(StrutsConstants.STRUTS_MULTIPART_ENABLED, Objects.toString(multipartEnabled, null));
         map.put(StrutsConstants.STRUTS_MULTIPART_VALIDATION_REGEX, Objects.toString(multipartValidationRegex, null));

core/src/main/java/org/apache/struts2/dispatcher/Dispatcher.java

@@ -147,7 +147,7 @@ public class Dispatcher {
     private String defaultLocale;
 
     /**
-     * Store state of StrutsConstants.STRUTS_MULTIPART_SAVEDIR setting.
+     * Store state of {@link StrutsConstants#STRUTS_MULTIPART_SAVE_DIR} setting.
      */
     private String multipartSaveDir;
 
@@ -315,7 +315,7 @@ public class Dispatcher {
      *
      * @param val New setting
      */
-    @Inject(StrutsConstants.STRUTS_MULTIPART_SAVEDIR)
+    @Inject(StrutsConstants.STRUTS_MULTIPART_SAVE_DIR)
     public void setMultipartSaveDir(String val) {
         multipartSaveDir = val;
     }
@@ -323,7 +323,7 @@ public class Dispatcher {
     /**
      * @deprecated since 6.4.0, no replacement.
      */
-    @Deprecated(since = "6.4.9", forRemoval = true)
+    @Deprecated(since = "6.4.0", forRemoval = true)
     public void setMultipartHandler(String val) {
         // no-op
     }
@@ -868,11 +868,12 @@ public class Dispatcher {
      * @return the path to save uploaded files to
      */
     protected String getSaveDir() {
-        String saveDir = multipartSaveDir.trim();
+        String saveDir = Objects.toString(multipartSaveDir, "").trim();
 
-        if (saveDir.equals("")) {
-            File tempdir = (File) servletContext.getAttribute("jakarta.servlet.context.tempdir");
-            LOG.info("Unable to find 'struts.multipart.saveDir' property setting. Defaulting to jakarta.servlet.context.tempdir");
+        if (saveDir.isEmpty()) {
+            File tempdir = (File) servletContext.getAttribute(ServletContext.TEMPDIR);
+            LOG.info("Unable to find: {} property setting. Defaulting to: {}",
+                    StrutsConstants.STRUTS_MULTIPART_SAVE_DIR, ServletContext.TEMPDIR);
 
             if (tempdir != null) {
                 saveDir = tempdir.toString();
@@ -885,9 +886,9 @@ public class Dispatcher {
                 if (!multipartSaveDir.mkdirs()) {
                     String logMessage;
                     try {
-                        logMessage = "Could not find create multipart save directory '" + multipartSaveDir.getCanonicalPath() + "'.";
+                        logMessage = "Could not create multipart save directory '" + multipartSaveDir.getCanonicalPath() + "'.";
                     } catch (IOException e) {
-                        logMessage = "Could not find create multipart save directory '" + multipartSaveDir.toString() + "'.";
+                        logMessage = "Could not create multipart save directory '" + multipartSaveDir + "'.";
                     }
                     if (devMode) {
                         LOG.error(logMessage);

core/src/main/java/org/apache/struts2/dispatcher/multipart/AbstractMultiPartRequest.java

@@ -18,23 +18,35 @@
  */
 package org.apache.struts2.dispatcher.multipart;
 
-import com.opensymphony.xwork2.LocaleProviderFactory;
 import com.opensymphony.xwork2.inject.Inject;
+import jakarta.servlet.http.HttpServletRequest;
+import org.apache.commons.fileupload2.core.FileUploadByteCountLimitException;
+import org.apache.commons.fileupload2.core.FileUploadContentTypeException;
+import org.apache.commons.fileupload2.core.FileUploadException;
+import org.apache.commons.fileupload2.core.FileUploadFileCountLimitException;
+import org.apache.commons.fileupload2.core.FileUploadSizeException;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
+import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.struts2.StrutsConstants;
 import org.apache.struts2.dispatcher.LocalizedMessage;
 
-import jakarta.servlet.http.HttpServletRequest;
+import java.io.IOException;
+import java.nio.charset.Charset;
+import java.nio.file.Path;
 import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.List;
-import java.util.Locale;
+import java.util.Map;
 
 /**
  * Abstract class with some helper methods, it should be used
  * when starting development of another implementation of {@link MultiPartRequest}
  */
-public abstract class AbstractMultiPartRequest implements MultiPartRequest {
+public abstract class AbstractMultiPartRequest<T> implements MultiPartRequest {
 
     protected static final String STRUTS_MESSAGES_UPLOAD_ERROR_PARAMETER_TOO_LONG_KEY = "struts.messages.upload.error.parameter.too.long";
 
@@ -55,6 +67,11 @@ public abstract class AbstractMultiPartRequest implements MultiPartRequest {
      */
     protected Long maxSize;
 
+    /**
+     * Specifies the maximum size of all the uploaded files.
+     */
+    protected Long maxSizeOfFiles;
+
     /**
      * Specifies the maximum number of files in one request.
      */
@@ -75,17 +92,25 @@ public abstract class AbstractMultiPartRequest implements MultiPartRequest {
      */
     protected int bufferSize = BUFFER_SIZE;
 
+    /**
+     * Defines default encoding to encode data from request used if not provided with request
+     */
     protected String defaultEncoding;
 
     /**
-     * Localization to be used regarding errors.
+     * Map between file fields and file data.
      */
-    protected Locale defaultLocale = Locale.ENGLISH;
+    protected Map<String, List<UploadedFile<T>>> uploadedFiles = new HashMap<>();
+
+    /**
+     * Map between non-file fields and values.
+     */
+    protected Map<String, List<String>> parameters = new HashMap<>();
 
     /**
      * @param bufferSize Sets the buffer size to be used.
      */
-    @Inject(value = StrutsConstants.STRUTS_MULTIPART_BUFFERSIZE, required = false)
+    @Inject(value = StrutsConstants.STRUTS_MULTIPART_BUFFER_SIZE, required = false)
     public void setBufferSize(String bufferSize) {
         this.bufferSize = Integer.parseInt(bufferSize);
     }
@@ -98,45 +123,154 @@ public abstract class AbstractMultiPartRequest implements MultiPartRequest {
     /**
      * @param maxSize Injects the Struts multipart request maximum size.
      */
-    @Inject(StrutsConstants.STRUTS_MULTIPART_MAXSIZE)
+    @Inject(StrutsConstants.STRUTS_MULTIPART_MAX_SIZE)
     public void setMaxSize(String maxSize) {
         this.maxSize = Long.parseLong(maxSize);
     }
 
-    @Inject(StrutsConstants.STRUTS_MULTIPART_MAXFILES)
+    /**
+     * @param maxSizeOfFiles Injects the Struts maximum size of all uploaded files.
+     */
+    @Inject(value = StrutsConstants.STRUTS_MULTIPART_MAX_SIZE_OF_FILES, required = false)
+    public void setMaxSizeOfFiles(String maxSizeOfFiles) {
+        this.maxSizeOfFiles = Long.parseLong(maxSizeOfFiles);
+    }
+
+    /**
+     * @param maxFiles Injects the Struts maximum size of an individual file uploaded.
+     */
+    @Inject(StrutsConstants.STRUTS_MULTIPART_MAX_FILES)
     public void setMaxFiles(String maxFiles) {
         this.maxFiles = Long.parseLong(maxFiles);
     }
 
-    @Inject(value = StrutsConstants.STRUTS_MULTIPART_MAXFILESIZE, required = false)
+    /**
+     * @param maxFileSize Injects the Struts maximum number of files, which can be uploaded.
+     */
+    @Inject(value = StrutsConstants.STRUTS_MULTIPART_MAX_FILE_SIZE, required = false)
     public void setMaxFileSize(String maxFileSize) {
         this.maxFileSize = Long.parseLong(maxFileSize);
     }
 
+    /**
+     * @param maxStringLength Injects the Struts maximum size of single form field.
+     */
     @Inject(StrutsConstants.STRUTS_MULTIPART_MAX_STRING_LENGTH)
     public void setMaxStringLength(String maxStringLength) {
         this.maxStringLength = Long.parseLong(maxStringLength);
     }
 
-    @Inject
-    public void setLocaleProviderFactory(LocaleProviderFactory localeProviderFactory) {
-        defaultLocale = localeProviderFactory.createLocaleProvider().getLocale();
+    /**
+     * Process the request extract file upload data
+     *
+     * @param request current {@link HttpServletRequest}
+     * @param saveDir a temporary directory to store files
+     */
+    protected abstract void processUpload(HttpServletRequest request, String saveDir) throws IOException;
+
+    /**
+     * @param request multipart request
+     * @return character encoding from request or {@link #defaultEncoding}
+     */
+    protected Charset readCharsetEncoding(HttpServletRequest request) {
+        String charsetStr = StringUtils.isBlank(request.getCharacterEncoding())
+                ? defaultEncoding
+                : request.getCharacterEncoding();
+
+        return Charset.forName(charsetStr);
     }
 
     /**
-     * @param request Inspect the servlet request and set the locale if one wasn't provided by
-     * the Struts2 framework.
+     * Creates an instance of {@link JakartaServletDiskFileUpload} used by the parser to extract uploaded files
+     *
+     * @param charset used charset from incoming request
+     * @param saveDir a temporary folder to store uploaded files (not always needed)
      */
-    protected void setLocale(HttpServletRequest request) {
-        if (defaultLocale == null) {
-            defaultLocale = request.getLocale();
+    protected abstract JakartaServletDiskFileUpload createJakartaFileUpload(Charset charset, Path saveDir);
+
+    protected JakartaServletDiskFileUpload prepareServletFileUpload(Charset charset, Path saveDir) {
+        JakartaServletDiskFileUpload servletFileUpload = createJakartaFileUpload(charset, saveDir);
+
+        if (maxSize != null) {
+            LOG.debug("Applies max size: {} to file upload request", maxSize);
+            servletFileUpload.setSizeMax(maxSize);
+        }
+        if (maxFiles != null) {
+            LOG.debug("Applies max files number: {} to file upload request", maxFiles);
+            servletFileUpload.setFileCountMax(maxFiles);
+        }
+        if (maxFileSize != null) {
+            LOG.debug("Applies max size of single file: {} to file upload request", maxFileSize);
+            servletFileUpload.setFileSizeMax(maxFileSize);
+        }
+        return servletFileUpload;
+    }
+
+    protected boolean exceedsMaxStringLength(String fieldName, String fieldValue) {
+        if (maxStringLength != null && fieldValue.length() > maxStringLength) {
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Form field: {} of size: {} bytes exceeds limit of: {}.",
+                        sanitizeNewlines(fieldName), fieldValue.length(), maxStringLength);
+            }
+            LocalizedMessage localizedMessage = new LocalizedMessage(this.getClass(),
+                    STRUTS_MESSAGES_UPLOAD_ERROR_PARAMETER_TOO_LONG_KEY, null,
+                    new Object[]{fieldName, maxStringLength, fieldValue.length()});
+            if (!errors.contains(localizedMessage)) {
+                errors.add(localizedMessage);
+            }
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Processes the upload.
+     *
+     * @param request the servlet request
+     * @param saveDir location of the save dir
+     */
+    public void parse(HttpServletRequest request, String saveDir) throws IOException {
+        try {
+            processUpload(request, saveDir);
+        } catch (FileUploadException e) {
+            LOG.debug("Request exceeded size limit!", e);
+            LocalizedMessage errorMessage;
+            if (e instanceof FileUploadByteCountLimitException ex) {
+                errorMessage = buildErrorMessage(e, new Object[]{
+                        ex.getFieldName(), ex.getFileName(), ex.getPermitted(), ex.getActualSize()
+                });
+            } else if (e instanceof FileUploadFileCountLimitException ex) {
+                errorMessage = buildErrorMessage(e, new Object[]{
+                        ex.getPermitted(), ex.getActualSize()
+                });
+            } else if (e instanceof FileUploadSizeException ex) {
+                errorMessage = buildErrorMessage(e, new Object[]{
+                        ex.getPermitted(), ex.getActualSize()
+                });
+            } else if (e instanceof FileUploadContentTypeException ex) {
+                errorMessage = buildErrorMessage(e, new Object[]{
+                        ex.getContentType()
+                });
+            } else {
+                errorMessage = buildErrorMessage(e, new Object[]{});
+            }
+
+            if (!errors.contains(errorMessage)) {
+                errors.add(errorMessage);
+            }
+        } catch (IOException e) {
+            LOG.debug("Unable to parse request", e);
+            LocalizedMessage errorMessage = buildErrorMessage(e, new Object[]{});
+            if (!errors.contains(errorMessage)) {
+                errors.add(errorMessage);
+            }
         }
     }
 
     /**
      * Build error message.
      *
-     * @param e the Throwable/Exception
+     * @param e    the Throwable/Exception
      * @param args arguments
      * @return error message
      */
@@ -147,13 +281,6 @@ public abstract class AbstractMultiPartRequest implements MultiPartRequest {
         return new LocalizedMessage(this.getClass(), errorKey, e.getMessage(), args);
     }
 
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getErrors()
-    */
-    public List<LocalizedMessage> getErrors() {
-        return errors;
-    }
-
     /**
      * @param originalFileName file name
      * @return the canonical name based on the supplied filename
@@ -171,4 +298,109 @@ public abstract class AbstractMultiPartRequest implements MultiPartRequest {
         return fileName;
     }
 
+    protected String sanitizeNewlines(String before) {
+        return before.replaceAll("\\R", "_");
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getErrors()
+     */
+    public List<LocalizedMessage> getErrors() {
+        return errors;
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileParameterNames()
+     */
+    public Enumeration<String> getFileParameterNames() {
+        return Collections.enumeration(uploadedFiles.keySet());
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getContentType(java.lang.String)
+     */
+    public String[] getContentType(String fieldName) {
+        return uploadedFiles.getOrDefault(fieldName, Collections.emptyList()).stream()
+                .map(UploadedFile::getContentType)
+                .toArray(String[]::new);
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFile(java.lang.String)
+     */
+    @SuppressWarnings("unchecked")
+    public UploadedFile<T>[] getFile(String fieldName) {
+        return uploadedFiles.getOrDefault(fieldName, Collections.emptyList())
+                .toArray(UploadedFile[]::new);
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileNames(java.lang.String)
+     */
+    public String[] getFileNames(String fieldName) {
+        return uploadedFiles.getOrDefault(fieldName, Collections.emptyList()).stream()
+                .map(file -> getCanonicalName(file.getName()))
+                .toArray(String[]::new);
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFilesystemName(java.lang.String)
+     */
+    public String[] getFilesystemName(String fieldName) {
+        return uploadedFiles.getOrDefault(fieldName, Collections.emptyList()).stream()
+                .map(UploadedFile::getAbsolutePath)
+                .toArray(String[]::new);
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameter(java.lang.String)
+     */
+    public String getParameter(String name) {
+        List<String> paramValue = parameters.getOrDefault(name, Collections.emptyList());
+        if (!paramValue.isEmpty()) {
+            return paramValue.get(0);
+        }
+
+        return null;
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterNames()
+     */
+    public Enumeration<String> getParameterNames() {
+        return Collections.enumeration(parameters.keySet());
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterValues(java.lang.String)
+     */
+    public String[] getParameterValues(String name) {
+        return parameters.getOrDefault(name, Collections.emptyList())
+                .toArray(String[]::new);
+    }
+
+    /* (non-Javadoc)
+     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#cleanUp()
+     */
+    public void cleanUp() {
+        try {
+            LOG.debug("Performing File Upload temporary storage cleanup.");
+            for (List<UploadedFile<T>> uploadedFileList : uploadedFiles.values()) {
+                for (UploadedFile<T> uploadedFile : uploadedFileList) {
+                    if (uploadedFile.isFile()) {
+                        LOG.debug("Deleting file: {}", uploadedFile.getName());
+                        if (!uploadedFile.delete()) {
+                            LOG.warn("There was a problem attempting to delete file: {}", uploadedFile.getName());
+                        }
+                    } else {
+                        LOG.debug("File: {} already deleted", uploadedFile.getName());
+                    }
+                }
+            }
+        } finally {
+            uploadedFiles = new HashMap<>();
+            parameters = new HashMap<>();
+        }
+    }
+
 }

core/src/main/java/org/apache/struts2/dispatcher/multipart/JakartaMultiPartRequest.java

@@ -21,375 +21,108 @@ package org.apache.struts2.dispatcher.multipart;
 import jakarta.servlet.http.HttpServletRequest;
 import org.apache.commons.fileupload2.core.DiskFileItem;
 import org.apache.commons.fileupload2.core.DiskFileItemFactory;
-import org.apache.commons.fileupload2.core.FileItem;
-import org.apache.commons.fileupload2.core.FileUploadByteCountLimitException;
-import org.apache.commons.fileupload2.core.FileUploadContentTypeException;
-import org.apache.commons.fileupload2.core.FileUploadException;
-import org.apache.commons.fileupload2.core.FileUploadFileCountLimitException;
-import org.apache.commons.fileupload2.core.FileUploadSizeException;
-import org.apache.commons.fileupload2.core.RequestContext;
-import org.apache.commons.fileupload2.jakarta.JakartaServletFileUpload;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
 import org.apache.commons.lang3.StringUtils;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.struts2.dispatcher.LocalizedMessage;
 
 import java.io.File;
 import java.io.IOException;
-import java.io.InputStream;
-import java.io.UncheckedIOException;
 import java.nio.charset.Charset;
+import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Enumeration;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.Set;
 
 /**
- * Multipart form data request adapter for Jakarta Commons Fileupload package.
+ * Multipart form data request adapter for Jakarta Commons FileUpload package.
  */
-public class JakartaMultiPartRequest extends AbstractMultiPartRequest {
+public class JakartaMultiPartRequest extends AbstractMultiPartRequest<File> {
 
-    static final Logger LOG = LogManager.getLogger(JakartaMultiPartRequest.class);
-
-    // maps parameter name -> List of FileItem objects
-    protected Map<String, List<FileItem>> files = new HashMap<>();
-
-    // maps parameter name -> List of param values
-    protected Map<String, List<String>> params = new HashMap<>();
-
-    /**
-     * Creates a new request wrapper to handle multipart data using methods adapted from Jason Pell's
-     * multipart classes (see class description).
-     *
-     * @param saveDir the directory to save off the file
-     * @param request the request containing the multipart
-     * @throws java.io.IOException is thrown if encoding fails.
-     */
-    public void parse(HttpServletRequest request, String saveDir) throws IOException {
-        try {
-            setLocale(request);
-            processUpload(request, saveDir);
-        } catch (FileUploadException e) {
-            LOG.debug("Request exceeded size limit!", e);
-            LocalizedMessage errorMessage;
-            if (e instanceof FileUploadByteCountLimitException) {
-                FileUploadByteCountLimitException ex = (FileUploadByteCountLimitException) e;
-                errorMessage = buildErrorMessage(e, new Object[]{
-                        ex.getFieldName(), ex.getFileName(), ex.getPermitted(), ex.getActualSize()
-                });
-            } else if (e instanceof FileUploadFileCountLimitException) {
-                FileUploadFileCountLimitException ex = (FileUploadFileCountLimitException) e;
-                errorMessage = buildErrorMessage(e, new Object[]{
-                        ex.getPermitted(), ex.getActualSize()
-                });
-            } else if (e instanceof FileUploadSizeException) {
-                FileUploadSizeException ex = (FileUploadSizeException) e;
-                errorMessage = buildErrorMessage(e, new Object[]{
-                        ex.getPermitted(), ex.getActualSize()
-                });
-            } else if (e instanceof FileUploadContentTypeException) {
-                FileUploadContentTypeException ex = (FileUploadContentTypeException) e;
-                errorMessage = buildErrorMessage(e, new Object[]{
-                        ex.getContentType()
-                });
-            } else {
-                errorMessage = buildErrorMessage(e, new Object[]{});
-            }
-
-            if (!errors.contains(errorMessage)) {
-                errors.add(errorMessage);
-            }
-        } catch (Exception e) {
-            LOG.debug("Unable to parse request", e);
-            LocalizedMessage errorMessage = buildErrorMessage(e, new Object[]{});
-            if (!errors.contains(errorMessage)) {
-                errors.add(errorMessage);
-            }
-        }
-    }
+    private static final Logger LOG = LogManager.getLogger(JakartaMultiPartRequest.class);
 
+    @Override
     protected void processUpload(HttpServletRequest request, String saveDir) throws IOException {
+        Charset charset = readCharsetEncoding(request);
 
-        if (JakartaServletFileUpload.isMultipartContent(request)) {
-            for (FileItem item : parseRequest(request, saveDir)) {
-                LOG.debug("Found file item: [{}]", sanitizeNewlines(item.getFieldName()));
-                if (item.isFormField()) {
-                    processNormalFormField(item, request.getCharacterEncoding());
-                } else {
-                    processFileField(item);
-                }
+        JakartaServletDiskFileUpload servletFileUpload =
+                prepareServletFileUpload(charset, Path.of(saveDir));
+
+        for (DiskFileItem item : servletFileUpload.parseRequest(request)) {
+            LOG.debug(() -> "Processing a form field: " + sanitizeNewlines(item.getFieldName()));
+            if (item.isFormField()) {
+                processNormalFormField(item, charset);
+            } else {
+                LOG.debug(() -> "Processing a file: " + sanitizeNewlines(item.getFieldName()));
+                processFileField(item);
             }
         }
     }
 
-    protected void processFileField(FileItem item) {
-        LOG.debug("Item is a file upload");
+    protected JakartaServletDiskFileUpload createJakartaFileUpload(Charset charset, Path saveDir) {
+        DiskFileItemFactory.Builder builder = DiskFileItemFactory.builder();
 
-        // Skip file uploads that don't have a file name - meaning that no file was selected.
-        if (item.getName() == null || item.getName().trim().isEmpty()) {
-            LOG.debug("No file has been uploaded for the field: {}", sanitizeNewlines(item.getFieldName()));
-            return;
-        }
+        LOG.debug("Using file save directory: {}", saveDir);
+        builder.setPath(saveDir);
 
-        List<FileItem> values;
-        if (files.get(item.getFieldName()) != null) {
-            values = files.get(item.getFieldName());
+        LOG.debug("Sets minimal buffer size to always write file to disk");
+        builder.setBufferSize(1);
+
+        LOG.debug("Using charset: {}", charset);
+        builder.setCharset(charset);
+
+        DiskFileItemFactory factory = builder.get();
+        return new JakartaServletDiskFileUpload(factory);
+    }
+
+    protected void processNormalFormField(DiskFileItem item, Charset charset) throws IOException {
+        LOG.debug("Item: {} is a normal form field", item.getName());
+
+        List<String> values;
+        String fieldName = item.getFieldName();
+        if (parameters.get(fieldName) != null) {
+            values = parameters.get(fieldName);
         } else {
             values = new ArrayList<>();
         }
 
-        values.add(item);
-        files.put(item.getFieldName(), values);
+        String fieldValue = item.getString(charset);
+        if (exceedsMaxStringLength(fieldName, fieldValue)) {
+            return;
+        }
+        if (item.getSize() == 0) {
+            values.add(StringUtils.EMPTY);
+        } else {
+            values.add(fieldValue);
+        }
+        parameters.put(fieldName, values);
     }
 
-    protected void processNormalFormField(FileItem item, String charset) throws IOException {
-        try {
-            LOG.debug("Item is a normal form field");
-            Charset encoding = Charset.forName(charset);
-
-            List<String> values;
-            if (params.get(item.getFieldName()) != null) {
-                values = params.get(item.getFieldName());
-            } else {
-                values = new ArrayList<>();
-            }
-
-            long size = item.getSize();
-            if (size > maxStringLength) {
-                LOG.debug("Form field {} of size {} bytes exceeds limit of {}.", sanitizeNewlines(item.getFieldName()), size, maxStringLength);
-                LocalizedMessage localizedMessage = new LocalizedMessage(this.getClass(),
-                        STRUTS_MESSAGES_UPLOAD_ERROR_PARAMETER_TOO_LONG_KEY, null,
-                        new Object[]{item.getFieldName(), maxStringLength, size});
-                if (!errors.contains(localizedMessage)) {
-                    errors.add(localizedMessage);
-                }
-                return;
-            }
-            if (size == 0) {
-                values.add(StringUtils.EMPTY);
-            } else if (charset == null) {
-                values.add(item.getString()); // WW-633
-            } else {
-                values.add(item.getString(encoding));
-            }
-            params.put(item.getFieldName(), values);
-        } finally {
-            item.delete();
-        }
-    }
-
-    protected List<FileItem> parseRequest(HttpServletRequest servletRequest, String saveDir) throws FileUploadException {
-        DiskFileItemFactory fac = createDiskFileItemFactory(saveDir);
-        JakartaServletFileUpload upload = createServletFileUpload(fac);
-
-
-        return upload.parseRequest(createRequestContext(servletRequest));
-    }
-
-    protected JakartaServletFileUpload createServletFileUpload(DiskFileItemFactory fac) {
-        JakartaServletFileUpload upload = new JakartaServletFileUpload(fac);
-        if (maxSize != null) {
-            upload.setSizeMax(maxSize);
-        }
-        if (maxFiles != null) {
-            upload.setFileCountMax(maxFiles);
-        }
-        if (maxFileSize != null) {
-            upload.setFileSizeMax(maxFileSize);
-        }
-        return upload;
-    }
-
-    protected DiskFileItemFactory createDiskFileItemFactory(String saveDir) {
-        DiskFileItemFactory.Builder fac = DiskFileItemFactory.builder();
-        // Make sure that the data is written to file, even if the file is empty.
-        //setting 0 or -1 no longer seems to work for fileupload buffer size, so using 1 instead.
-        fac.setBufferSize(1);
-        if (saveDir != null) {
-            fac.setPath(saveDir);
-        }
-        return fac.get();
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileParameterNames()
-     */
-    public Enumeration<String> getFileParameterNames() {
-        return Collections.enumeration(files.keySet());
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getContentType(java.lang.String)
-     */
-    public String[] getContentType(String fieldName) {
-        List<FileItem> items = files.get(fieldName);
-
-        if (items == null) {
-            return null;
+    protected void processFileField(DiskFileItem item) {
+        // Skip file uploads that don't have a file name - meaning that no file was selected.
+        if (item.getName() == null || item.getName().trim().isEmpty()) {
+            LOG.debug(() -> "No file has been uploaded for the field: " + sanitizeNewlines(item.getFieldName()));
+            return;
         }
 
-        List<String> contentTypes = new ArrayList<>(items.size());
-        for (FileItem fileItem : items) {
-            contentTypes.add(fileItem.getContentType());
+        List<UploadedFile<File>> values;
+        if (uploadedFiles.get(item.getFieldName()) != null) {
+            values = uploadedFiles.get(item.getFieldName());
+        } else {
+            values = new ArrayList<>();
         }
 
-        return contentTypes.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFile(java.lang.String)
-     */
-    public UploadedFile[] getFile(String fieldName) {
-        List<FileItem> items = files.get(fieldName);
-
-        if (items == null) {
-            return null;
-        }
-
-        List<UploadedFile> fileList = new ArrayList<>(items.size());
-        for (FileItem fileItem : items) {
-            DiskFileItem diskFileItem = (DiskFileItem) fileItem;
-            File storeLocation = diskFileItem.getPath().toFile();
-
-            // Ensure file exists even if it is empty.
-            if (diskFileItem.getSize() == 0 && !storeLocation.exists()) {
-                try {
-                    storeLocation.createNewFile();
-                } catch (IOException e) {
-                    LOG.error("Cannot write uploaded empty file to disk: {}", storeLocation.getAbsolutePath(), e);
-                }
-            }
-            UploadedFile uploadedFile = StrutsUploadedFile.Builder.create(storeLocation)
-                    .withContentType(fileItem.getContentType())
-                    .withOriginalName(fileItem.getName())
+        if (item.isInMemory()) {
+            LOG.warn("Storing uploaded files just in memory isn't supported currently, skipping file: {}!", item.getName());
+        } else {
+            UploadedFile<File> uploadedFile = StrutsUploadedFile.Builder
+                    .create(item.getPath().toFile())
+                    .withOriginalName(item.getName())
+                    .withContentType(item.getContentType())
                     .build();
-            fileList.add(uploadedFile);
+            values.add(uploadedFile);
         }
 
-        return fileList.toArray(new UploadedFile[0]);
+        uploadedFiles.put(item.getFieldName(), values);
     }
 
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileNames(java.lang.String)
-     */
-    public String[] getFileNames(String fieldName) {
-        List<FileItem> items = files.get(fieldName);
-
-        if (items == null) {
-            return null;
-        }
-
-        List<String> fileNames = new ArrayList<>(items.size());
-        for (FileItem fileItem : items) {
-            fileNames.add(getCanonicalName(fileItem.getName()));
-        }
-
-        return fileNames.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFilesystemName(java.lang.String)
-     */
-    public String[] getFilesystemName(String fieldName) {
-        List<FileItem> items = files.get(fieldName);
-
-        if (items == null) {
-            return null;
-        }
-
-        List<String> fileNames = new ArrayList<>(items.size());
-        for (FileItem fileItem : items) {
-            fileNames.add(((DiskFileItem) fileItem).getPath().toFile().getName());
-        }
-
-        return fileNames.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameter(java.lang.String)
-     */
-    public String getParameter(String name) {
-        List<String> v = params.get(name);
-        if (v != null && !v.isEmpty()) {
-            return v.get(0);
-        }
-
-        return null;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterNames()
-     */
-    public Enumeration<String> getParameterNames() {
-        return Collections.enumeration(params.keySet());
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterValues(java.lang.String)
-     */
-    public String[] getParameterValues(String name) {
-        List<String> v = params.get(name);
-        if (v != null && !v.isEmpty()) {
-            return v.toArray(new String[0]);
-        }
-
-        return null;
-    }
-
-    /**
-     * Creates a RequestContext needed by Jakarta Commons Upload.
-     *
-     * @param req the request.
-     * @return a new request context.
-     */
-    protected RequestContext createRequestContext(final HttpServletRequest req) {
-        return new RequestContext() {
-            public String getCharacterEncoding() {
-                return req.getCharacterEncoding();
-            }
-
-            public String getContentType() {
-                return req.getContentType();
-            }
-
-            public long getContentLength() {
-                return req.getContentLength();
-            }
-
-            public InputStream getInputStream() throws IOException {
-                InputStream in = req.getInputStream();
-                if (in == null) {
-                    throw new IOException("Missing content in the request");
-                }
-                return req.getInputStream();
-            }
-        };
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#cleanUp()
-     */
-    public void cleanUp() {
-        Set<String> names = files.keySet();
-        for (String name : names) {
-            List<FileItem> items = files.get(name);
-            for (FileItem item : items) {
-                LOG.debug("Removing file {} {}", name, item);
-                if (!item.isInMemory()) {
-                    try {
-                        item.delete();
-                    } catch (IOException e) {
-                        throw new UncheckedIOException(e);
-                    }
-                }
-            }
-        }
-    }
-
-    private String sanitizeNewlines(String before) {
-        return before.replaceAll("[\n\r]", "_");
-    }
 }

core/src/main/java/org/apache/struts2/dispatcher/multipart/JakartaStreamMultiPartRequest.java

@@ -18,30 +18,28 @@
  */
 package org.apache.struts2.dispatcher.multipart;
 
-import org.apache.commons.fileupload2.core.DiskFileItem;
+import jakarta.servlet.http.HttpServletRequest;
 import org.apache.commons.fileupload2.core.DiskFileItemFactory;
-import org.apache.commons.fileupload2.jakarta.JakartaServletFileUpload;
-import org.apache.commons.fileupload2.core.FileUploadSizeException;
-import org.apache.commons.fileupload2.core.FileItemInputIterator;
 import org.apache.commons.fileupload2.core.FileItemInput;
+import org.apache.commons.fileupload2.core.FileUploadFileCountLimitException;
+import org.apache.commons.fileupload2.core.FileUploadSizeException;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 import org.apache.struts2.dispatcher.LocalizedMessage;
 
-import jakarta.servlet.http.HttpServletRequest;
 import java.io.BufferedOutputStream;
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
-import java.io.Serializable;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.ArrayList;
-import java.util.Collections;
-import java.util.Enumeration;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 import java.util.UUID;
 
 /**
@@ -52,155 +50,9 @@ import java.util.UUID;
  *
  * @since 2.3.18
  */
-public class JakartaStreamMultiPartRequest extends AbstractMultiPartRequest {
+public class JakartaStreamMultiPartRequest extends AbstractMultiPartRequest<File> {
 
-    static final Logger LOG = LogManager.getLogger(JakartaStreamMultiPartRequest.class);
-
-    /**
-     * Map between file fields and file data.
-     */
-    protected Map<String, List<FileInfo>> fileInfos = new HashMap<>();
-
-    /**
-     * Map between non-file fields and values.
-     */
-    protected Map<String, List<String>> parameters = new HashMap<>();
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#cleanUp()
-     */
-    public void cleanUp() {
-        LOG.debug("Performing File Upload temporary storage cleanup.");
-        for (List<FileInfo> fileInfoList : fileInfos.values()) {
-            for (FileInfo fileInfo : fileInfoList) {
-                File file = fileInfo.getFile();
-                LOG.debug("Deleting file '{}'.", file.getName());
-                if (!file.delete()) {
-                    LOG.warn("There was a problem attempting to delete file '{}'.", file.getName());
-                }
-            }
-        }
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getContentType(java.lang.String)
-     */
-    public String[] getContentType(String fieldName) {
-        List<FileInfo> infos = fileInfos.get(fieldName);
-        if (infos == null) {
-            return null;
-        }
-
-        List<String> types = new ArrayList<>(infos.size());
-        for (FileInfo fileInfo : infos) {
-            types.add(fileInfo.getContentType());
-        }
-
-        return types.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFile(java.lang.String)
-     */
-    public UploadedFile[] getFile(String fieldName) {
-        List<FileInfo> infos = fileInfos.get(fieldName);
-        if (infos == null) {
-            return null;
-        }
-
-        return infos.stream().map(fileInfo ->
-            StrutsUploadedFile.Builder.create(fileInfo.getFile())
-                .withContentType(fileInfo.contentType)
-                .withOriginalName(fileInfo.originalName)
-                .build()
-        ).toArray(UploadedFile[]::new);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileNames(java.lang.String)
-     */
-    public String[] getFileNames(String fieldName) {
-        List<FileInfo> infos = fileInfos.get(fieldName);
-        if (infos == null) {
-            return null;
-        }
-
-        List<String> names = new ArrayList<>(infos.size());
-        for (FileInfo fileInfo : infos) {
-            names.add(getCanonicalName(fileInfo.getOriginalName()));
-        }
-
-        return names.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFileParameterNames()
-     */
-    public Enumeration<String> getFileParameterNames() {
-        return Collections.enumeration(fileInfos.keySet());
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getFilesystemName(java.lang.String)
-     */
-    public String[] getFilesystemName(String fieldName) {
-        List<FileInfo> infos = fileInfos.get(fieldName);
-        if (infos == null) {
-            return null;
-        }
-
-        List<String> names = new ArrayList<>(infos.size());
-        for (FileInfo fileInfo : infos) {
-            names.add(fileInfo.getFile().getName());
-        }
-
-        return names.toArray(new String[0]);
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameter(java.lang.String)
-     */
-    public String getParameter(String name) {
-        List<String> values = parameters.get(name);
-        if (values != null && !values.isEmpty()) {
-            return values.get(0);
-        }
-        return null;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterNames()
-     */
-    public Enumeration<String> getParameterNames() {
-        return Collections.enumeration(parameters.keySet());
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#getParameterValues(java.lang.String)
-     */
-    public String[] getParameterValues(String name) {
-        List<String> values = parameters.get(name);
-        if (values != null && !values.isEmpty()) {
-            return values.toArray(new String[0]);
-        }
-        return null;
-    }
-
-    /* (non-Javadoc)
-     * @see org.apache.struts2.dispatcher.multipart.MultiPartRequest#parse(jakarta.servlet.http.HttpServletRequest, java.lang.String)
-     */
-    public void parse(HttpServletRequest request, String saveDir) throws IOException {
-        try {
-            setLocale(request);
-            processUpload(request, saveDir);
-        } catch (Exception e) {
-            LOG.debug("Error occurred during parsing of multi part request", e);
-            LocalizedMessage errorMessage = buildErrorMessage(e, new Object[]{});
-            if (!errors.contains(errorMessage)) {
-                errors.add(errorMessage);
-            }
-        }
-    }
+    private static final Logger LOG = LogManager.getLogger(JakartaStreamMultiPartRequest.class);
 
     /**
      * Processes the upload.
@@ -208,153 +60,147 @@ public class JakartaStreamMultiPartRequest extends AbstractMultiPartRequest {
      * @param request the servlet request
      * @param saveDir location of the save dir
      */
-    protected void processUpload(HttpServletRequest request, String saveDir) throws Exception {
+    @Override
+    protected void processUpload(HttpServletRequest request, String saveDir) throws IOException {
+        Charset charset = readCharsetEncoding(request);
+        Path location = Path.of(saveDir);
 
-        // Sanity check that the request is a multi-part/form-data request.
-        if (JakartaServletFileUpload.isMultipartContent(request)) {
+        JakartaServletDiskFileUpload servletFileUpload =
+                prepareServletFileUpload(charset, location);
 
-            // Sanity check on request size.
-            boolean requestSizePermitted = isRequestSizePermitted(request);
-
-            // Interface with Commons FileUpload API
-            // Using the Streaming API
-            JakartaServletFileUpload<DiskFileItem, DiskFileItemFactory> servletFileUpload = new JakartaServletFileUpload<>();
-            if (maxSize != null) {
-                servletFileUpload.setSizeMax(maxSize);
-            }
-            if (maxFiles != null) {
-                servletFileUpload.setFileCountMax(maxFiles);
-            }
-            if (maxFileSize != null) {
-                servletFileUpload.setFileSizeMax(maxFileSize);
-            }
-            FileItemInputIterator i = servletFileUpload.getItemIterator(request);
-
-            // Iterate the file items
-            while (i.hasNext()) {
-                try {
-                    FileItemInput itemStream = i.next();
-
-                    // If the file item stream is a form field, delegate to the
-                    // field item stream handler
-                    if (itemStream.isFormField()) {
-                        processFileItemStreamAsFormField(itemStream);
-                    }
-
-                    // Delegate the file item stream for a file field to the
-                    // file item stream handler, but delegation is skipped
-                    // if the requestSizePermitted check failed based on the
-                    // complete content-size of the request.
-                    else {
-
-                        // prevent processing file field item if request size not allowed.
-                        if (!requestSizePermitted) {
-                            addFileSkippedError(itemStream.getName(), request);
-                            LOG.debug("Skipped stream '{}', request maximum size ({}) exceeded.", itemStream.getName(), maxSize);
-                            continue;
-                        }
-
-                        processFileItemStreamAsFileField(itemStream, saveDir);
-                    }
-                } catch (IOException e) {
-                    LOG.warn("Error occurred during process upload", e);
-                }
-            }
-        }
-    }
-
-    /**
-     * Defines whether the request allowed based on content length.
-     *
-     * @param request the servlet request
-     * @return true if request size is permitted
-     */
-    protected boolean isRequestSizePermitted(HttpServletRequest request) {
-        // if maxSize is specified as -1, there is no sanity check and it's
-        // safe to return true for any request, delegating the failure
-        // checks later in the upload process.
-        if (maxSize == null || maxSize == -1 || request == null) {
-            return true;
-        }
-        return request.getContentLength() < maxSize;
-    }
-
-    /**
-     * @param request the servlet request
-     * @return the request content length.
-     */
-    protected long getRequestSize(HttpServletRequest request) {
-        return request != null ? request.getContentLength() : 0;
-    }
-
-    /**
-     * Add a file skipped message notification for action messages.
-     *
-     * @param fileName file name
-     * @param request  the servlet request
-     */
-    protected void addFileSkippedError(String fileName, HttpServletRequest request) {
-        String exceptionMessage = "Skipped file " + fileName + "; request size limit exceeded.";
-        long allowedMaxSize = maxSize != null ? maxSize : -1;
-        FileUploadSizeException exception = new FileUploadSizeException(exceptionMessage, getRequestSize(request), allowedMaxSize);
-        LocalizedMessage message = buildErrorMessage(exception, new Object[]{fileName, getRequestSize(request), allowedMaxSize});
-        if (!errors.contains(message)) {
-            errors.add(message);
-        }
-    }
-
-    /**
-     * Processes the FileItemStream as a Form Field.
-     *
-     * @param itemStream file item stream
-     */
-    protected void processFileItemStreamAsFormField(FileItemInput itemStream) {
-        String fieldName = itemStream.getFieldName();
-        try {
-            List<String> values;
-
-            String fieldValue = itemStream.getInputStream().toString();
-            if (!parameters.containsKey(fieldName)) {
-                values = new ArrayList<>();
-                parameters.put(fieldName, values);
+        LOG.debug("Using Jakarta Stream API to process request");
+        servletFileUpload.getItemIterator(request).forEachRemaining(item -> {
+            if (item.isFormField()) {
+                LOG.debug(() -> "Processing a form field: " + sanitizeNewlines(item.getFieldName()));
+                processFileItemAsFormField(item);
             } else {
-                values = parameters.get(fieldName);
+                LOG.debug(() -> "Processing a file: " + sanitizeNewlines(item.getFieldName()));
+                processFileItemAsFileField(item, location);
             }
-            values.add(fieldValue);
-        } catch (IOException e) {
-            LOG.warn("Failed to handle form field '{}'.", fieldName, e);
+        });
+    }
+
+    protected JakartaServletDiskFileUpload createJakartaFileUpload(Charset charset, Path location) {
+        DiskFileItemFactory.Builder builder = DiskFileItemFactory.builder();
+
+        LOG.debug("Using file save directory: {}", location);
+        builder.setPath(location);
+
+        LOG.debug("Sets buffer size: {}", bufferSize);
+        builder.setBufferSize(bufferSize);
+
+        LOG.debug("Using charset: {}", charset);
+        builder.setCharset(charset);
+
+        DiskFileItemFactory factory = builder.get();
+        return new JakartaServletDiskFileUpload(factory);
+    }
+
+    private String readStream(InputStream inputStream) throws IOException {
+        ByteArrayOutputStream result = new ByteArrayOutputStream();
+        byte[] buffer = new byte[1024];
+        for (int length; (length = inputStream.read(buffer)) != -1; ) {
+            result.write(buffer, 0, length);
         }
+        return result.toString(StandardCharsets.UTF_8);
     }
 
     /**
-     * Processes the FileItemStream as a file field.
+     * Processes the FileItem as a normal form field.
      *
-     * @param itemStream file item stream
-     * @param location   location
+     * @param fileItemInput a form field item input
      */
-    protected void processFileItemStreamAsFileField(FileItemInput itemStream, String location) {
-        // Skip file uploads that don't have a file name - meaning that no file was selected.
-        if (itemStream.getName() == null || itemStream.getName().trim().isEmpty()) {
-            LOG.debug("No file has been uploaded for the field: {}", itemStream.getFieldName());
+    protected void processFileItemAsFormField(FileItemInput fileItemInput) throws IOException {
+        String fieldName = fileItemInput.getFieldName();
+        String fieldValue = readStream(fileItemInput.getInputStream());
+
+        if (exceedsMaxStringLength(fieldName, fieldValue)) {
             return;
         }
 
-        File file = null;
-        try {
-            // Create the temporary upload file.
-            file = createTemporaryFile(itemStream.getName(), location);
+        List<String> values;
+        if (parameters.containsKey(fieldName)) {
+            values = parameters.get(fieldName);
+        } else {
+            values = new ArrayList<>();
+            parameters.put(fieldName, values);
+        }
+        values.add(fieldValue);
+    }
 
-            if (streamFileToDisk(itemStream, file)) {
-                createFileInfoFromItemStream(itemStream, file);
+    /**
+     * @return actual size of already uploaded files
+     */
+    protected Long actualSizeOfUploadedFiles() {
+        return uploadedFiles.values().stream()
+                .map(files -> files.stream().map(UploadedFile::length).reduce(0L, Long::sum))
+                .reduce(0L, Long::sum);
+    }
+
+    private boolean exceedsMaxFiles(FileItemInput fileItemInput) {
+        if (maxFiles != null && maxFiles == uploadedFiles.size()) {
+            if (LOG.isDebugEnabled()) {
+                LOG.debug("Cannot accept another file: {} as it will exceed max files: {}",
+                        sanitizeNewlines(fileItemInput.getName()), maxFiles);
             }
-        } catch (IOException e) {
-            if (file != null) {
-                try {
-                    file.delete();
-                } catch (SecurityException se) {
-                    LOG.warn("Failed to delete '{}' due to security exception above.", file.getName(), se);
-                }
+            LocalizedMessage errorMessage = buildErrorMessage(new FileUploadFileCountLimitException(
+                            String.format("File %s exceeds allowed maximum number of files %s",
+                                    fileItemInput.getName(), maxFiles),
+                            maxFiles, uploadedFiles.size()),
+                    new Object[]{maxFiles, uploadedFiles.size()});
+            if (!errors.contains(errorMessage)) {
+                errors.add(errorMessage);
             }
+            return true;
+        }
+        return false;
+    }
+
+    private void exceedsMaxSizeOfFiles(FileItemInput fileItemInput, File file, Long currentFilesSize) {
+        if (LOG.isDebugEnabled()) {
+            LOG.debug("File: {} of size: {} exceeds allowed max size: {}, actual size of already uploaded files: {}",
+                    sanitizeNewlines(fileItemInput.getName()), file.length(), maxSizeOfFiles, currentFilesSize
+            );
+        }
+        LocalizedMessage errorMessage = buildErrorMessage(new FileUploadSizeException(
+                        String.format("Size %s of file %s exceeds allowed max size %s",
+                                file.length(), fileItemInput.getName(), maxSizeOfFiles),
+                        maxSizeOfFiles, currentFilesSize),
+                new Object[]{maxSizeOfFiles, currentFilesSize});
+        if (!errors.contains(errorMessage)) {
+            errors.add(errorMessage);
+        }
+        if (!file.delete() && LOG.isWarnEnabled()) {
+            LOG.warn("Cannot delete file: {} which exceeds maximum size: {} of all files!",
+                    sanitizeNewlines(fileItemInput.getName()), maxSizeOfFiles);
+        }
+    }
+
+    /**
+     * Processes the FileItem as a file field.
+     *
+     * @param fileItemInput file item representing upload file
+     * @param location      location
+     */
+    protected void processFileItemAsFileField(FileItemInput fileItemInput, Path location) throws IOException {
+        // Skip file uploads that don't have a file name - meaning that no file was selected.
+        if (fileItemInput.getName() == null || fileItemInput.getName().trim().isEmpty()) {
+            LOG.debug(() -> "No file has been uploaded for the field: " + sanitizeNewlines(fileItemInput.getFieldName()));
+            return;
+        }
+
+        if (exceedsMaxFiles(fileItemInput)) {
+            return;
+        }
+
+        File file = createTemporaryFile(fileItemInput.getName(), location);
+        streamFileToDisk(fileItemInput, file);
+
+        Long currentFilesSize = maxSizeOfFiles != null ? actualSizeOfUploadedFiles() : null;
+        if (maxSizeOfFiles != null && currentFilesSize + file.length() >= maxSizeOfFiles) {
+            exceedsMaxSizeOfFiles(fileItemInput, file, currentFilesSize);
+        } else {
+            createUploadedFile(fileItemInput, file);
         }
     }
 
@@ -363,121 +209,54 @@ public class JakartaStreamMultiPartRequest extends AbstractMultiPartRequest {
      *
      * @param fileName file name
      * @param location location
-     * @return temporary file based on the given filename and location
-     * @throws IOException in case of IO errors
+     * @return a temporary file based on the given filename and location
      */
-    protected File createTemporaryFile(String fileName, String location) throws IOException {
-        String name = fileName
-            .substring(fileName.lastIndexOf('/') + 1)
-            .substring(fileName.lastIndexOf('\\') + 1);
-
-        String prefix = name;
-        String suffix = "";
-
-        if (name.contains(".")) {
-            prefix = name.substring(0, name.lastIndexOf('.'));
-            suffix = name.substring(name.lastIndexOf('.'));
-        }
-
-        if (prefix.length() < 3) {
-            prefix = UUID.randomUUID().toString();
-        }
-
-        File file = File.createTempFile(prefix + "_", suffix, new File(location));
-        LOG.debug("Creating temporary file '{}' (originally '{}').", file.getName(), fileName);
+    protected File createTemporaryFile(String fileName, Path location) {
+        String uid = UUID.randomUUID().toString().replace("-", "_");
+        File file = location.resolve("upload_" + uid + ".tmp").toFile();
+        LOG.debug("Creating temporary file: {} (originally: {})", file.getName(), fileName);
         return file;
     }
 
     /**
      * Streams the file upload stream to the specified file.
      *
-     * @param itemStream file item stream
-     * @param file       the file
-     * @return true if stream was successfully
-     * @throws IOException in case of IO errors
+     * @param fileItemInput file item input
+     * @param file          the file
      */
-    protected boolean streamFileToDisk(FileItemInput itemStream, File file) throws IOException {
-        boolean result;
-        try (InputStream input = itemStream.getInputStream();
-                OutputStream output = new BufferedOutputStream(Files.newOutputStream(file.toPath()), bufferSize)) {
+    protected void streamFileToDisk(FileItemInput fileItemInput, File file) throws IOException {
+        InputStream input = fileItemInput.getInputStream();
+        try (OutputStream output = new BufferedOutputStream(Files.newOutputStream(file.toPath()), bufferSize)) {
             byte[] buffer = new byte[bufferSize];
-            LOG.debug("Streaming file using buffer size {}.", bufferSize);
+            LOG.debug("Streaming file: {} using buffer size: {}", fileItemInput.getName(), bufferSize);
             for (int length; ((length = input.read(buffer)) > 0); ) {
                 output.write(buffer, 0, length);
             }
-            result = true;
         }
-        return result;
     }
 
     /**
-     * Creates an internal <code>FileInfo</code> structure used to pass information
-     * to the <code>FileUploadInterceptor</code> during the interceptor stack
-     * invocation process.
+     * Create {@link UploadedFile} abstraction over uploaded file
      *
-     * @param itemStream file item stream
-     * @param file       the file
+     * @param fileItemInput file item stream
+     * @param file          the file
      */
-    protected void createFileInfoFromItemStream(FileItemInput itemStream, File file) {
-        // gather attributes from file upload stream.
-        String fileName = itemStream.getName();
-        String fieldName = itemStream.getFieldName();
-        // create internal structure
-        FileInfo fileInfo = new FileInfo(file, itemStream.getContentType(), fileName);
-        // append or create new entry.
-        if (!fileInfos.containsKey(fieldName)) {
-            List<FileInfo> infos = new ArrayList<>();
-            infos.add(fileInfo);
-            fileInfos.put(fieldName, infos);
+    protected void createUploadedFile(FileItemInput fileItemInput, File file) {
+        String fileName = fileItemInput.getName();
+        String fieldName = fileItemInput.getFieldName();
+
+        UploadedFile<File> uploadedFile = StrutsUploadedFile.Builder
+                .create(file)
+                .withOriginalName(fileName)
+                .withContentType(fileItemInput.getContentType())
+                .build();
+
+        if (uploadedFiles.containsKey(fieldName)) {
+            uploadedFiles.get(fieldName).add(uploadedFile);
         } else {
-            fileInfos.get(fieldName).add(fileInfo);
-        }
-    }
-
-    /**
-     * Internal data structure used to store a reference to information needed
-     * to later pass post processing data to the <code>FileUploadInterceptor</code>.
-     *
-     * @since 7.0.0
-     */
-    public static class FileInfo implements Serializable {
-
-        private final File file;
-        private final String contentType;
-        private final String originalName;
-
-        /**
-         * Default constructor.
-         *
-         * @param file         the file
-         * @param contentType  content type
-         * @param originalName original file name
-         */
-        public FileInfo(File file, String contentType, String originalName) {
-            this.file = file;
-            this.contentType = contentType;
-            this.originalName = originalName;
-        }
-
-        /**
-         * @return the file
-         */
-        public File getFile() {
-            return file;
-        }
-
-        /**
-         * @return content type
-         */
-        public String getContentType() {
-            return contentType;
-        }
-
-        /**
-         * @return original file name
-         */
-        public String getOriginalName() {
-            return originalName;
+            List<UploadedFile<File>> infos = new ArrayList<>();
+            infos.add(uploadedFile);
+            uploadedFiles.put(fieldName, infos);
         }
     }
 

core/src/main/java/org/apache/struts2/dispatcher/multipart/MultiPartRequest.java

@@ -32,7 +32,7 @@ import jakarta.servlet.http.HttpServletRequest;
 public interface MultiPartRequest {
 
     void parse(HttpServletRequest request, String saveDir) throws IOException;
-    
+
     /**
      * Returns an enumeration of the parameter names for uploaded files
      *
@@ -58,7 +58,7 @@ public interface MultiPartRequest {
      * @param fieldName input field name
      * @return a UploadedFile[] object for files associated with the specified input field name
      */
-    UploadedFile[] getFile(String fieldName);
+    <T> UploadedFile<T>[] getFile(String fieldName);
 
     /**
      * Returns a String[] of file names for files associated with the specified input field name

core/src/main/java/org/apache/struts2/dispatcher/multipart/MultiPartRequestWrapper.java

@@ -25,6 +25,8 @@ import org.apache.struts2.dispatcher.LocalizedMessage;
 import org.apache.struts2.dispatcher.StrutsRequestWrapper;
 
 import jakarta.servlet.http.HttpServletRequest;
+
+import java.io.File;
 import java.io.IOException;
 import java.util.*;
 
@@ -137,7 +139,7 @@ public class MultiPartRequestWrapper extends StrutsRequestWrapper {
      * @param fieldName input field name
      * @return a File[] object for files associated with the specified input field name
      */
-    public UploadedFile[] getFiles(String fieldName) {
+    public UploadedFile<File>[] getFiles(String fieldName) {
         if (multi == null) {
             return null;
         }

core/src/main/java/org/apache/struts2/dispatcher/multipart/StrutsUploadedFile.java

@@ -20,7 +20,7 @@ package org.apache.struts2.dispatcher.multipart;
 
 import java.io.File;
 
-public class StrutsUploadedFile implements UploadedFile {
+public class StrutsUploadedFile implements UploadedFile<File> {
 
     private final File file;
     private final String contentType;
@@ -28,6 +28,7 @@ public class StrutsUploadedFile implements UploadedFile {
 
     /**
      * Use builder instead of constructor
+     *
      * @param file an uploaded file
      * @deprecated since Struts 6.4.0
      */
@@ -87,9 +88,9 @@ public class StrutsUploadedFile implements UploadedFile {
     @Override
     public String toString() {
         return "StrutsUploadedFile{" +
-            "contentType='" + contentType + '\'' +
-            ", originalName='" + originalName + '\'' +
-            '}';
+                "contentType='" + contentType + '\'' +
+                ", originalName='" + originalName + '\'' +
+                '}';
     }
 
     public static class Builder {
@@ -115,7 +116,7 @@ public class StrutsUploadedFile implements UploadedFile {
             return this;
         }
 
-        public UploadedFile build() {
+        public UploadedFile<File> build() {
             return new StrutsUploadedFile(this.file, this.contentType, this.originalName);
         }
     }

core/src/main/java/org/apache/struts2/dispatcher/multipart/UploadedFile.java

@@ -21,24 +21,48 @@ package org.apache.struts2.dispatcher.multipart;
 import java.io.Serializable;
 
 /**
- * Virtual representation of a uploaded file used by {@link MultiPartRequest}
+ * Virtual representation of an uploaded file used by {@link MultiPartRequest}
  */
-public interface UploadedFile extends Serializable {
+public interface UploadedFile<T> extends Serializable {
 
+    /**
+     * @return size of the content of file/stream/array
+     */
     Long length();
 
+    /**
+     * @return a local name of the file
+     */
     String getName();
 
+    /**
+     * @return original file name from upload source
+     */
     String getOriginalName();
 
+    /**
+     * @return indicates if this is a real file or maybe just in-memory stream
+     */
     boolean isFile();
 
+    /**
+     * @return removes a local copy of the uploaded file/stream
+     */
     boolean delete();
 
+    /**
+     * @return an absolute path of the file if possible
+     */
     String getAbsolutePath();
 
-    Object getContent();
+    /**
+     * @return content of the upload file
+     */
+    T getContent();
 
+    /**
+     * @return content type of the uploaded file
+     */
     String getContentType();
 
 }

core/src/main/java/org/apache/struts2/interceptor/ActionFileUploadInterceptor.java

@@ -28,6 +28,7 @@ import org.apache.struts2.action.UploadedFilesAware;
 import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
 import org.apache.struts2.dispatcher.multipart.UploadedFile;
 
+import java.io.File;
 import java.util.ArrayList;
 import java.util.Enumeration;
 import java.util.List;
@@ -153,19 +154,19 @@ public class ActionFileUploadInterceptor extends AbstractFileUploadInterceptor {
 
         // bind allowed Files
         Enumeration<String> fileParameterNames = multiWrapper.getFileParameterNames();
-        List<UploadedFile> acceptedFiles = new ArrayList<>();
+        List<UploadedFile<File>> acceptedFiles = new ArrayList<>();
 
         while (fileParameterNames != null && fileParameterNames.hasMoreElements()) {
             // get the value of this input tag
             String inputName = fileParameterNames.nextElement();
-            UploadedFile[] uploadedFiles = multiWrapper.getFiles(inputName);
+            UploadedFile<File>[] uploadedFiles = multiWrapper.getFiles(inputName);
 
             if (uploadedFiles == null || uploadedFiles.length == 0) {
                 if (LOG.isWarnEnabled()) {
                     LOG.warn(getTextMessage(action, STRUTS_MESSAGES_INVALID_FILE_KEY, new String[]{inputName}));
                 }
             } else {
-                for (UploadedFile uploadedFile : uploadedFiles) {
+                for (UploadedFile<File> uploadedFile : uploadedFiles) {
                     if (acceptFile(action, uploadedFile, uploadedFile.getOriginalName(), uploadedFile.getContentType(), inputName)) {
                         acceptedFiles.add(uploadedFile);
                     }

core/src/test/java/org/apache/struts2/config/SettingsTest.java

@@ -35,8 +35,8 @@ public class SettingsTest extends StrutsInternalTestCase {
     public void testSettings() {
         Settings settings = new DefaultSettings();
 
-        assertEquals("12345", settings.get(StrutsConstants.STRUTS_MULTIPART_MAXSIZE));
-        assertEquals("\\temp", settings.get(StrutsConstants.STRUTS_MULTIPART_SAVEDIR));
+        assertEquals("12345", settings.get(StrutsConstants.STRUTS_MULTIPART_MAX_SIZE));
+        assertEquals("\\temp", settings.get(StrutsConstants.STRUTS_MULTIPART_SAVE_DIR));
 
         assertEquals("test,org/apache/struts2/othertest", settings.get( StrutsConstants.STRUTS_CUSTOM_PROPERTIES));
         assertEquals("testvalue", settings.get("testkey"));

core/src/test/java/org/apache/struts2/dispatcher/multipart/AbstractMultiPartRequestTest.java

@@ -0,0 +1,485 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.struts2.dispatcher.multipart;
+
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
+import org.apache.struts2.dispatcher.LocalizedMessage;
+import org.assertj.core.api.InstanceOfAssertFactories;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.springframework.mock.web.MockHttpServletRequest;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+abstract class AbstractMultiPartRequestTest {
+
+    protected static Path tempDir;
+
+    protected MockHttpServletRequest mockRequest;
+
+    protected final String boundary = "_boundary_";
+    protected final String endline = "\r\n";
+
+    protected AbstractMultiPartRequest<File> multiPart;
+
+    abstract protected AbstractMultiPartRequest<File> createMultipartRequest();
+
+    @BeforeClass
+    public static void beforeClass() {
+        String dirProp = System.getProperty("java.io.tmpdir");
+        if (Path.of(dirProp).toFile().exists()) {
+            tempDir = Path.of(dirProp, "multi-part-test");
+        } else {
+            tempDir = Path.of("target", "multi-part-test");
+        }
+    }
+
+    @Before
+    public void before() {
+        mockRequest = new MockHttpServletRequest();
+        mockRequest.setCharacterEncoding(StandardCharsets.UTF_8.name());
+        mockRequest.setMethod("post");
+        mockRequest.setContentType("multipart/form-data; boundary=" + boundary);
+
+        multiPart = createMultipartRequest();
+    }
+
+    @After
+    public void after() {
+        multiPart.cleanUp();
+    }
+
+    @Test
+    public void uploadedFilesToDisk() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.setBufferSize("1"); // always write files into disk
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .containsOnly("file1", "file2");
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test1.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent()).asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("1,2,3,4");
+        });
+        assertThat(multiPart.getFile("file2")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test2.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("5,6,7,8");
+        });
+    }
+
+    @Test
+    public void uploadedMultipleFilesToDisk() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file1", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.setBufferSize("1"); // always write files into disk
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .containsOnly("file1");
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            if (Objects.equals(file.getName(), "test1.csv")) {
+                assertThat(file.isFile())
+                        .isTrue();
+                assertThat(file.getOriginalName())
+                        .isEqualTo("test1.csv");
+                assertThat(file.getContentType())
+                        .isEqualTo("text/csv");
+                assertThat(file.getContent()).asInstanceOf(InstanceOfAssertFactories.FILE)
+                        .exists()
+                        .content()
+                        .isEqualTo("1,2,3,4");
+            }
+            if (Objects.equals(file.getName(), "test2.csv")) {
+                assertThat(file.isFile())
+                        .isTrue();
+                assertThat(file.getOriginalName())
+                        .isEqualTo("test2.csv");
+                assertThat(file.getContentType())
+                        .isEqualTo("text/csv");
+                assertThat(file.getContent())
+                        .asInstanceOf(InstanceOfAssertFactories.FILE)
+                        .exists()
+                        .content()
+                        .isEqualTo("5,6,7,8");
+            }
+        });
+    }
+
+    @Test
+    public void uploadedFilesWithLargeBuffer() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.setBufferSize("8192"); // streams files into disk using larger buffer
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .containsOnly("file1", "file2");
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test1.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("1,2,3,4");
+        });
+        assertThat(multiPart.getFile("file2")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test2.csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("5,6,7,8");
+        });
+    }
+
+    @Test
+    public void cleanUp() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .containsOnly("file1", "file2");
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test1.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent()).asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("1,2,3,4");
+        });
+        assertThat(multiPart.getFile("file2")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test2.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("5,6,7,8");
+        });
+
+        List<UploadedFile<File>> uploadedFiles = new ArrayList<>();
+        for (Map.Entry<String, List<UploadedFile<File>>> entry : multiPart.uploadedFiles.entrySet()) {
+            uploadedFiles.addAll(entry.getValue());
+        }
+
+        // when
+        multiPart.cleanUp();
+
+        // then
+        assertThat(multiPart.uploadedFiles)
+                .isEmpty();
+        assertThat(multiPart.parameters)
+                .isEmpty();
+        assertThat(uploadedFiles).allSatisfy(file ->
+                assertThat(file.getContent()).asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .doesNotExist()
+        );
+    }
+
+    @Test
+    public void nonMultiPartUpload() throws IOException {
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        // given
+        mockRequest.setContentType("");
+
+        // when
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.FileUploadContentTypeException");
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .isEmpty();
+    }
+
+    @Test
+    public void maxSize() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.setMaxSize("1");
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.uploadedFiles)
+                .isEmpty();
+
+        assertThat(multiPart.getErrors())
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.FileUploadSizeException");
+    }
+
+    @Test
+    public void maxFilesSize() throws IOException {
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        multiPart.setMaxFileSize("1");
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        assertThat(multiPart.getErrors())
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.FileUploadByteCountLimitException");
+    }
+
+    @Test
+    public void maxFiles() throws IOException {
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.US_ASCII));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        multiPart.setMaxFiles("1");
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        assertThat(multiPart.errors)
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.FileUploadFileCountLimitException");
+    }
+
+    @Test
+    public void maxStringLength() throws IOException {
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                formField("longText", "very long text") +
+                formField("shortText", "short text") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        multiPart.setMaxStringLength("10");
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        assertThat(multiPart.getErrors())
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.parameter.too.long");
+    }
+
+    @Test
+    public void mismatchCharset() throws IOException {
+        // give
+        String content = formFile("file1", "test1.csv", "Ł,Ś,Ż,Ó") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        mockRequest.setCharacterEncoding(null);
+        multiPart.setDefaultEncoding(StandardCharsets.ISO_8859_1.name());
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getFileParameterNames().asIterator()).toIterable()
+                .asList()
+                .containsOnly("file1");
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test1.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("Ł,Ś,Ż,Ó");
+        });
+    }
+
+    @Test
+    public void normalFields() throws IOException {
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                formField("longText", "very long text") +
+                formField("shortText", "short text") +
+                formField("multi", "multi1") +
+                formField("multi", "multi2") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        assertThat(multiPart.getErrors())
+                .isEmpty();
+
+        assertThat(multiPart.getParameterNames().asIterator()).toIterable()
+                .containsOnly("longText", "shortText", "multi");
+        assertThat(multiPart.getParameterValues("longText"))
+                .contains("very long text");
+        assertThat(multiPart.getParameterValues("shortText"))
+                .contains("short text");
+        assertThat(multiPart.getParameter("longText"))
+                .isEqualTo("very long text");
+        assertThat(multiPart.getParameter("shortText"))
+                .isEqualTo("short text");
+        assertThat(multiPart.getParameterValues("multi"))
+                .containsOnly("multi1", "multi2");
+    }
+
+    protected String formFile(String fieldName, String filename, String content) {
+        return endline +
+                "--" + boundary + endline +
+                "Content-Disposition: form-data; name=\"" + fieldName + "\"; filename=\"" + filename + "\"" +
+                endline +
+                "Content-Type: text/csv" +
+                endline +
+                endline +
+                content;
+    }
+
+    protected String formField(String fieldName, String content) {
+        return endline +
+                "--" + boundary + endline +
+                "Content-Disposition: form-data; name=\"" + fieldName + "\"" +
+                endline +
+                endline +
+                content;
+    }
+}

core/src/test/java/org/apache/struts2/dispatcher/multipart/JakartaMultiPartRequestTest.java

@@ -0,0 +1,30 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.struts2.dispatcher.multipart;
+
+import java.io.File;
+
+public class JakartaMultiPartRequestTest extends AbstractMultiPartRequestTest {
+
+    @Override
+    protected AbstractMultiPartRequest<File> createMultipartRequest() {
+        return new JakartaMultiPartRequest();
+    }
+
+}

core/src/test/java/org/apache/struts2/dispatcher/multipart/JakartaStreamMultiPartRequestTest.java

@@ -18,54 +18,57 @@
  */
 package org.apache.struts2.dispatcher.multipart;
 
-import java.io.ByteArrayInputStream;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
+import org.apache.struts2.dispatcher.LocalizedMessage;
+import org.assertj.core.api.InstanceOfAssertFactories;
+import org.junit.Test;
+
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
-import java.nio.file.Path;
-import java.nio.file.Paths;
 
-import org.apache.struts2.dispatcher.LocalizedMessage;
-import org.junit.Assert;
-import org.junit.Before;
-import org.junit.Test;
-import org.mockito.Mockito;
-import org.springframework.mock.web.DelegatingServletInputStream;
+import static org.assertj.core.api.Assertions.assertThat;
 
-import jakarta.servlet.http.HttpServletRequest;
+public class JakartaStreamMultiPartRequestTest extends AbstractMultiPartRequestTest {
 
-public class JakartaStreamMultiPartRequestTest {
-
-    private JakartaStreamMultiPartRequest multiPart;
-    private Path tempDir;
-
-    @Before
-    public void initialize() {
-        multiPart = new JakartaStreamMultiPartRequest();
-        tempDir = Paths.get("target", "multi-part-test");
+    @Override
+    protected AbstractMultiPartRequest createMultipartRequest() {
+        return new JakartaStreamMultiPartRequest();
     }
 
-    /**
-     * Number of bytes in files greater than 2GB overflow the {@code int} primative.
-     * The {@link HttpServletRequest#getContentLength()} returns {@literal -1}
-     * when the header is not present or the size is greater than {@link Integer#MAX_VALUE}.
-     */
     @Test
-    public void unknownContentLength() throws IOException {
-        HttpServletRequest request = Mockito.mock(HttpServletRequest.class);
-        Mockito.when(request.getContentType()).thenReturn("multipart/form-data; charset=utf-8; boundary=__X_BOUNDARY__");
-        Mockito.when(request.getMethod()).thenReturn("POST");
-        Mockito.when(request.getContentLength()).thenReturn(-1);
-        String entity = "\r\n--__X_BOUNDARY__\r\n" +
-            "Content-Disposition: form-data; name=\"upload\"; filename=\"test.csv\"\r\n" +
-            "Content-Type: text/csv\r\n\r\n1,2\r\n\r\n" +
-            "--__X_BOUNDARY__\r\n" +
-            "Content-Disposition: form-data; name=\"upload2\"; filename=\"test2.csv\"\r\n" +
-            "Content-Type: text/csv\r\n\r\n3,4\r\n\r\n" +
-            "--__X_BOUNDARY__--\r\n";
-        Mockito.when(request.getInputStream()).thenReturn(new DelegatingServletInputStream(new ByteArrayInputStream(entity.getBytes(StandardCharsets.UTF_8))));
-        multiPart.setMaxSize("4");
-        multiPart.parse(request, tempDir.toString());
-        LocalizedMessage next = multiPart.getErrors().iterator().next();
-        Assert.assertEquals(next.getTextKey(), "struts.messages.upload.error.FileUploadSizeException");
+    public void maxSizeOfFiles() throws IOException {
+        // given
+        String content = formFile("file1", "test1.csv", "1,2,3,4") +
+                formFile("file2", "test2.csv", "5,6,7,8") +
+                endline + "--" + boundary + "--";
+
+        mockRequest.setContent(content.getBytes(StandardCharsets.UTF_8));
+
+        assertThat(JakartaServletDiskFileUpload.isMultipartContent(mockRequest)).isTrue();
+
+        // when
+        multiPart.setMaxSizeOfFiles("10");
+        multiPart.parse(mockRequest, tempDir.toString());
+
+        // then
+        assertThat(multiPart.uploadedFiles)
+                .hasSize(1);
+        assertThat(multiPart.getFile("file1")).allSatisfy(file -> {
+            assertThat(file.isFile())
+                    .isTrue();
+            assertThat(file.getOriginalName())
+                    .isEqualTo("test1.csv");
+            assertThat(file.getContentType())
+                    .isEqualTo("text/csv");
+            assertThat(file.getContent())
+                    .asInstanceOf(InstanceOfAssertFactories.FILE)
+                    .exists()
+                    .content()
+                    .isEqualTo("1,2,3,4");
+        });
+        assertThat(multiPart.getErrors())
+                .map(LocalizedMessage::getTextKey)
+                .containsExactly("struts.messages.upload.error.FileUploadSizeException");
     }
+
 }

core/src/test/java/org/apache/struts2/interceptor/ActionFileUploadInterceptorTest.java

@@ -26,8 +26,8 @@ import com.opensymphony.xwork2.mock.MockActionInvocation;
 import com.opensymphony.xwork2.mock.MockActionProxy;
 import com.opensymphony.xwork2.util.ClassLoaderUtil;
 import jakarta.servlet.http.HttpServletRequest;
-import org.apache.commons.fileupload2.jakarta.JakartaServletDiskFileUpload;
-import org.apache.commons.fileupload2.jakarta.JakartaServletFileUpload;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletDiskFileUpload;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletFileUpload;
 import org.apache.struts2.ServletActionContext;
 import org.apache.struts2.StrutsInternalTestCase;
 import org.apache.struts2.action.UploadedFilesAware;
@@ -52,7 +52,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
 
-    public static final UploadedFile EMPTY_FILE = new UploadedFile() {
+    private static final UploadedFile<String> EMPTY_FILE = new UploadedFile<>() {
         @Override
         public Long length() {
             return 0L;
@@ -79,8 +79,8 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         }
 
         @Override
-        public byte[] getContent() {
-            return new byte[0];
+        public String getContent() {
+            return "";
         }
 
         @Override
@@ -210,7 +210,7 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         URL url = ClassLoaderUtil.getResource("log4j2.xml", ActionFileUploadInterceptorTest.class);
         File file = new File(new URI(url.toString()));
         assertTrue("log4j2.xml should be in src/test folder", file.exists());
-        UploadedFile uploadedFile = StrutsUploadedFile.Builder.create(file).withContentType("text/html").withOriginalName("filename").build();
+        UploadedFile<File> uploadedFile = StrutsUploadedFile.Builder.create(file).withContentType("text/html").withOriginalName("filename").build();
         boolean notOk = interceptor.acceptFile(validation, uploadedFile, "filename", "text/html", "inputName");
 
         assertFalse(notOk);
@@ -221,15 +221,15 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         String msg = errors.get(0);
         // the error message should contain at least this test
         assertThat(msg).contains(
-            "The file is too large to be uploaded",
-            "inputName",
-            "log4j2.xml",
-            "allowed mx size is 10"
+                "The file is too large to be uploaded",
+                "inputName",
+                "log4j2.xml",
+                "allowed mx size is 10"
         );
     }
 
     public void testNoMultipartRequest() throws Exception {
-        MyFileUploadAction action = new MyFileUploadAction();
+        MyFileUploadAction<File> action = new MyFileUploadAction<>();
 
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
@@ -250,13 +250,13 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         req.setContentType("multipart/form-data"); // not a multipart contentype
         req.setMethod("post");
 
-        MyFileUploadAction action = container.inject(MyFileUploadAction.class);
+        MyFileUploadAction<File> action = container.inject(MyFileUploadAction.class);
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
 
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
@@ -271,13 +271,13 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         req.addHeader("Content-type", "multipart/form-data");
         req.setContent(null); // there is no content
 
-        MyFileUploadAction action = container.inject(MyFileUploadAction.class);
+        MyFileUploadAction<File> action = container.inject(MyFileUploadAction.class);
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
 
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
@@ -301,19 +301,19 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
                 """);
         req.setContent(content.getBytes(StandardCharsets.US_ASCII));
 
-        MyFileUploadAction action = new MyFileUploadAction();
+        MyFileUploadAction<File> action = new MyFileUploadAction<>();
 
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
         assertFalse(action.hasErrors());
 
-        List<UploadedFile> files = action.getUploadFiles();
+        List<UploadedFile<File>> files = action.getUploadFiles();
 
         assertNotNull(files);
         assertEquals(1, files.size());
@@ -329,33 +329,27 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         MockHttpServletRequest req = new MockHttpServletRequest();
         req.setCharacterEncoding(StandardCharsets.UTF_8.name());
         req.setMethod("POST");
-        req.addHeader("Content-type", "multipart/form-data; boundary=" + boundary);
+        req.addHeader("Content-type", "multipart/form-data; boundary=\"" + boundary + "\"");
         String content = encodeTextFile("test.html", "text/plain", plainContent) +
-            encodeTextFile("test1.html", "text/html", htmlContent) +
-            encodeTextFile("test2.html", "text/html", htmlContent) +
-            endline +
-            endline +
-            endline +
-            "--" +
-            boundary +
-            "--" +
-            endline;
+                encodeTextFile("test1.html", "text/html", htmlContent) +
+                encodeTextFile("test2.html", "text/html", htmlContent) +
+                endline + "--" + boundary + "--";
         req.setContent(content.getBytes());
 
         assertTrue(JakartaServletDiskFileUpload.isMultipartContent(req));
 
-        MyFileUploadAction action = new MyFileUploadAction();
+        MyFileUploadAction<File> action = new MyFileUploadAction<>();
         container.inject(action);
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.setAllowedTypes("text/html");
         interceptor.intercept(mai);
 
-        List<UploadedFile> files = action.getUploadFiles();
+        List<UploadedFile<File>> files = action.getUploadFiles();
 
         assertNotNull(files);
         assertEquals("files accepted ", 2, files.size());
@@ -369,19 +363,19 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         req.setMethod("POST");
         req.addHeader("Content-type", "multipart/form-data; boundary=" + boundary);
         String content = encodeTextFile("test.html", "text/plain", plainContent) +
-            encodeTextFile("test1.html", "text/html", htmlContent) +
-            encodeTextFile("test2.html", "text/html", htmlContent) +
-            encodeTextFile("test3.html", "text/html", htmlContent) +
-            endline +
-            "--" +
-            boundary +
-            "--" +
-            endline;
+                encodeTextFile("test1.html", "text/html", htmlContent) +
+                encodeTextFile("test2.html", "text/html", htmlContent) +
+                encodeTextFile("test3.html", "text/html", htmlContent) +
+                endline +
+                "--" +
+                boundary +
+                "--" +
+                endline;
         req.setContent(content.getBytes());
 
         assertTrue(JakartaServletFileUpload.isMultipartContent(req));
 
-        MyFileUploadAction action = new MyFileUploadAction();
+        MyFileUploadAction<File> action = new MyFileUploadAction<>();
         container.inject(action);
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
@@ -417,14 +411,14 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
                 """);
         req.setContent(content.getBytes(StandardCharsets.US_ASCII));
 
-        MyFileUploadAction action = container.inject(MyFileUploadAction.class);
+        MyFileUploadAction<File> action = container.inject(MyFileUploadAction.class);
 
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
         ActionContext.getContext()
-            .withServletRequest(createMultipartRequestMaxFileSize(req));
+                .withServletRequest(createMultipartRequestMaxFileSize(req));
 
         interceptor.intercept(mai);
 
@@ -435,8 +429,8 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         String msg = errors.iterator().next();
         // FIXME: the expected size is 40 - length of the string
         assertEquals(
-            "File deleteme.txt assigned to file exceeded allowed size limit! Max size allowed is: 10 but file was: 10!",
-            msg);
+                "File deleteme.txt assigned to file exceeded allowed size limit! Max size allowed is: 10 but file was: 11!",
+                msg);
     }
 
     public void testMultipartRequestMaxStringLength() throws Exception {
@@ -464,14 +458,14 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
                 """);
         req.setContent(content.getBytes(StandardCharsets.US_ASCII));
 
-        MyFileUploadAction action = container.inject(MyFileUploadAction.class);
+        MyFileUploadAction<File> action = container.inject(MyFileUploadAction.class);
 
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
         ActionContext.getContext()
-            .withServletRequest(createMultipartRequestMaxStringLength(req));
+                .withServletRequest(createMultipartRequestMaxStringLength(req));
 
         interceptor.intercept(mai);
 
@@ -481,8 +475,8 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         assertEquals(1, errors.size());
         String msg = errors.iterator().next();
         assertEquals(
-            "The request parameter \"normalFormField2\" was too long. Max length allowed is 20, but found 27!",
-            msg);
+                "The request parameter \"normalFormField2\" was too long. Max length allowed is 20, but found 27!",
+                msg);
     }
 
     public void testMultipartRequestLocalizedError() throws Exception {
@@ -502,15 +496,15 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
                 """);
         req.setContent(content.getBytes(StandardCharsets.US_ASCII));
 
-        MyFileUploadAction action = container.inject(MyFileUploadAction.class);
+        MyFileUploadAction<File> action = container.inject(MyFileUploadAction.class);
 
         MockActionInvocation mai = new MockActionInvocation();
         mai.setAction(action);
         mai.setResultCode("success");
         mai.setInvocationContext(ActionContext.getContext());
         ActionContext.getContext()
-            .withLocale(Locale.GERMAN)
-            .withServletRequest(createMultipartRequestMaxSize(req, 10));
+                .withLocale(Locale.GERMAN)
+                .withServletRequest(createMultipartRequestMaxSize(req, 10));
 
         interceptor.intercept(mai);
 
@@ -524,20 +518,15 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
     }
 
     private String encodeTextFile(String filename, String contentType, String content) {
-        return "\r\n" +
-            "--" +
-            "simple boundary" +
-            "\r\n" +
-            "Content-Disposition: form-data; name=\"" +
-            "file" +
-            "\"; filename=\"" +
-            filename +
-            "\r\n" +
-            "Content-Type: " +
-            contentType +
-            "\r\n" +
-            "\r\n" +
-            content;
+        return endline +
+                "--" + boundary +
+                endline +
+                "Content-Disposition: form-data; name=\"" + "file" + "\"; filename=\"" + filename +
+                endline +
+                "Content-Type: " + contentType +
+                endline +
+                endline +
+                content;
     }
 
     private MultiPartRequestWrapper createMultipartRequestMaxFileSize(HttpServletRequest req) {
@@ -557,12 +546,12 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
     }
 
     private MultiPartRequestWrapper createMultipartRequest(HttpServletRequest req, int maxsize, int maxfilesize, int maxfiles, int maxStringLength) {
-
         JakartaMultiPartRequest jak = new JakartaMultiPartRequest();
         jak.setMaxSize(String.valueOf(maxsize));
         jak.setMaxFileSize(String.valueOf(maxfilesize));
         jak.setMaxFiles(String.valueOf(maxfiles));
         jak.setMaxStringLength(String.valueOf(maxStringLength));
+        jak.setDefaultEncoding(StandardCharsets.UTF_8.name());
         return new MultiPartRequestWrapper(jak, req, tempDir.getAbsolutePath(), new DefaultLocaleProvider());
     }
 
@@ -582,15 +571,15 @@ public class ActionFileUploadInterceptorTest extends StrutsInternalTestCase {
         super.tearDown();
     }
 
-    public static class MyFileUploadAction extends ActionSupport implements UploadedFilesAware {
-        private List<UploadedFile> uploadedFiles;
+    public static class MyFileUploadAction<T> extends ActionSupport implements UploadedFilesAware {
+        private List<UploadedFile<File>> uploadedFiles;
 
         @Override
-        public void withUploadedFiles(List<UploadedFile> uploadedFiles) {
+        public void withUploadedFiles(List<UploadedFile<File>> uploadedFiles) {
             this.uploadedFiles = uploadedFiles;
         }
 
-        public List<UploadedFile> getUploadFiles() {
+        public List<UploadedFile<File>> getUploadFiles() {
             return this.uploadedFiles;
         }
     }

core/src/test/java/org/apache/struts2/interceptor/FileUploadInterceptorTest.java

@@ -18,8 +18,24 @@
  */
 package org.apache.struts2.interceptor;
 
+import com.opensymphony.xwork2.ActionContext;
+import com.opensymphony.xwork2.ActionSupport;
+import com.opensymphony.xwork2.DefaultLocaleProvider;
+import com.opensymphony.xwork2.ValidationAwareSupport;
+import com.opensymphony.xwork2.mock.MockActionInvocation;
+import com.opensymphony.xwork2.util.ClassLoaderUtil;
+import jakarta.servlet.http.HttpServletRequest;
+import org.apache.commons.fileupload2.jakarta.servlet6.JakartaServletFileUpload;
+import org.apache.struts2.ServletActionContext;
+import org.apache.struts2.StrutsInternalTestCase;
+import org.apache.struts2.dispatcher.HttpParameters;
+import org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest;
+import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
+import org.apache.struts2.dispatcher.multipart.StrutsUploadedFile;
+import org.apache.struts2.dispatcher.multipart.UploadedFile;
+import org.springframework.mock.web.MockHttpServletRequest;
+
 import java.io.File;
-import java.io.IOException;
 import java.net.URI;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
@@ -29,35 +45,14 @@ import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 
-import org.apache.commons.fileupload2.jakarta.JakartaServletFileUpload;
-import org.apache.struts2.ServletActionContext;
-import org.apache.struts2.StrutsInternalTestCase;
-import org.apache.struts2.TestAction;
-import org.apache.struts2.dispatcher.HttpParameters;
-import org.apache.struts2.dispatcher.multipart.JakartaMultiPartRequest;
-import org.apache.struts2.dispatcher.multipart.MultiPartRequestWrapper;
-import org.apache.struts2.dispatcher.multipart.StrutsUploadedFile;
-import org.apache.struts2.dispatcher.multipart.UploadedFile;
-import org.springframework.mock.web.MockHttpServletRequest;
-
-import com.opensymphony.xwork2.ActionContext;
-import com.opensymphony.xwork2.ActionSupport;
-import com.opensymphony.xwork2.DefaultLocaleProvider;
-import com.opensymphony.xwork2.ValidationAwareSupport;
-import com.opensymphony.xwork2.mock.MockActionInvocation;
-import com.opensymphony.xwork2.util.ClassLoaderUtil;
-
-import jakarta.servlet.http.HttpServletRequest;
-
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * Test case for FileUploadInterceptor.
  */
-
 public class FileUploadInterceptorTest extends StrutsInternalTestCase {
 
-    public static final UploadedFile EMPTY_FILE = new UploadedFile() {
+    private static final UploadedFile<String> EMPTY_FILE = new UploadedFile<>() {
         @Override
         public Long length() {
             return 0L;
@@ -84,8 +79,8 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         }
 
         @Override
-        public byte[] getContent() {
-            return new byte[0];
+        public String getContent() {
+            return "";
         }
 
         @Override
@@ -210,7 +205,11 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         URL url = ClassLoaderUtil.getResource("log4j2.xml", FileUploadInterceptorTest.class);
         File file = new File(new URI(url.toString()));
         assertTrue("log4j2.xml should be in src/test folder", file.exists());
-        UploadedFile uploadedFile = StrutsUploadedFile.Builder.create(file).withContentType("text/html").withOriginalName("filename").build();
+        UploadedFile<File> uploadedFile = StrutsUploadedFile.Builder.create(file)
+                .withContentType("text/html")
+                .withOriginalName("filename")
+                .build();
+
         boolean notOk = interceptor.acceptFile(validation, uploadedFile, "filename", "text/html", "inputName");
 
         assertFalse(notOk);
@@ -221,10 +220,10 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         String msg = errors.get(0);
         // the error message should contain at least this test
         assertThat(msg).contains(
-            "The file is too large to be uploaded",
-            "inputName",
-            "log4j2.xml",
-            "allowed mx size is 10"
+                "The file is too large to be uploaded",
+                "inputName",
+                "log4j2.xml",
+                "allowed mx size is 10"
         );
     }
 
@@ -253,7 +252,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
 
         ActionContext.getContext().withParameters(HttpParameters.create().build());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
@@ -275,7 +274,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
 
         ActionContext.getContext().withParameters(HttpParameters.create().build());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
@@ -306,7 +305,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
         Map<String, Object> param = new HashMap<>();
         ActionContext.getContext().withParameters(HttpParameters.create(param).build());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.intercept(mai);
 
@@ -314,7 +313,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
 
         HttpParameters parameters = mai.getInvocationContext().getParameters();
         assertEquals(3, parameters.keySet().size());
-        UploadedFile[] files = (UploadedFile[]) parameters.get("file").getObject();
+        UploadedFile<File>[] files = (UploadedFile<File>[]) parameters.get("file").getObject();
         String[] fileContentTypes = parameters.get("fileContentType").getMultipleValues();
         String[] fileRealFilenames = parameters.get("fileFileName").getMultipleValues();
 
@@ -343,15 +342,15 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         req.setMethod("POST");
         req.addHeader("Content-type", "multipart/form-data; boundary=" + bondary);
         String content = encodeTextFile("test.html", "text/plain", plainContent) +
-            encodeTextFile("test1.html", "text/html", htmlContent) +
-            encodeTextFile("test2.html", "text/html", htmlContent) +
-            endline +
-            endline +
-            endline +
-            "--" +
-            bondary +
-            "--" +
-            endline;
+                encodeTextFile("test1.html", "text/html", htmlContent) +
+                encodeTextFile("test2.html", "text/html", htmlContent) +
+                endline +
+                endline +
+                endline +
+                "--" +
+                bondary +
+                "--" +
+                endline;
         req.setContent(content.getBytes());
 
         assertTrue(JakartaServletFileUpload.isMultipartContent(req));
@@ -364,14 +363,14 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
         Map<String, Object> param = new HashMap<>();
         ActionContext.getContext().withParameters(HttpParameters.create(param).build());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxSize(req, 2000));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxSize(req, 2000));
 
         interceptor.setAllowedTypes("text/html");
         interceptor.intercept(mai);
 
         HttpParameters parameters = mai.getInvocationContext().getParameters();
         assertEquals(3, parameters.keySet().size());
-        UploadedFile[] files = (UploadedFile[]) parameters.get("file").getObject();
+        UploadedFile<File>[] files = (UploadedFile<File>[]) parameters.get("file").getObject();
         String[] fileContentTypes = parameters.get("fileContentType").getMultipleValues();
         String[] fileRealFilenames = parameters.get("fileFileName").getMultipleValues();
 
@@ -396,14 +395,14 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         req.setMethod("POST");
         req.addHeader("Content-type", "multipart/form-data; boundary=" + boundary);
         String content = encodeTextFile("test.html", "text/plain", plainContent) +
-            encodeTextFile("test1.html", "text/html", htmlContent) +
-            encodeTextFile("test2.html", "text/html", htmlContent) +
-            encodeTextFile("test3.html", "text/html", htmlContent) +
-            endline +
-            "--" +
-            boundary +
-            "--" +
-            endline;
+                encodeTextFile("test1.html", "text/html", htmlContent) +
+                encodeTextFile("test2.html", "text/html", htmlContent) +
+                encodeTextFile("test3.html", "text/html", htmlContent) +
+                endline +
+                "--" +
+                boundary +
+                "--" +
+                endline;
         req.setContent(content.getBytes());
 
         assertTrue(JakartaServletFileUpload.isMultipartContent(req));
@@ -416,7 +415,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
         Map<String, Object> param = new HashMap<>();
         ActionContext.getContext().withParameters(HttpParameters.create(param).build());
-        ActionContext.getContext().put(ServletActionContext.HTTP_REQUEST, createMultipartRequestMaxFiles(req));
+        ActionContext.getContext().withServletRequest(createMultipartRequestMaxFiles(req));
 
         interceptor.setAllowedTypes("text/html");
         interceptor.intercept(mai);
@@ -466,7 +465,7 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         String msg = errors.iterator().next();
         // FIXME: the expected size is 40 - length of the string
         assertEquals(
-                "File deleteme.txt assigned to file exceeded allowed size limit! Max size allowed is: 10 but file was: 10!",
+                "File deleteme.txt assigned to file exceeded allowed size limit! Max size allowed is: 10 but file was: 11!",
                 msg);
     }
 
@@ -543,9 +542,9 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
         mai.setInvocationContext(ActionContext.getContext());
         Map<String, Object> param = new HashMap<>();
         ActionContext.getContext()
-            .withParameters(HttpParameters.create(param).build())
-            .withLocale(Locale.GERMAN)
-            .withServletRequest(createMultipartRequestMaxSize(req, 10));
+                .withParameters(HttpParameters.create(param).build())
+                .withLocale(Locale.GERMAN)
+                .withServletRequest(createMultipartRequestMaxSize(req, 10));
 
         interceptor.intercept(mai);
 
@@ -560,19 +559,19 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
 
     private String encodeTextFile(String filename, String contentType, String content) {
         return "\r\n" +
-            "--" +
-            "simple boundary" +
-            "\r\n" +
-            "Content-Disposition: form-data; name=\"" +
-            "file" +
-            "\"; filename=\"" +
-            filename +
-            "\r\n" +
-            "Content-Type: " +
-            contentType +
-            "\r\n" +
-            "\r\n" +
-            content;
+                "--" +
+                "simple boundary" +
+                "\r\n" +
+                "Content-Disposition: form-data; name=\"" +
+                "file" +
+                "\"; filename=\"" +
+                filename +
+                "\r\n" +
+                "Content-Type: " +
+                contentType +
+                "\r\n" +
+                "\r\n" +
+                content;
     }
 
     private MultiPartRequestWrapper createMultipartRequestMaxFileSize(HttpServletRequest req) {
@@ -592,12 +591,12 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
     }
 
     private MultiPartRequestWrapper createMultipartRequest(HttpServletRequest req, int maxsize, int maxfilesize, int maxfiles, int maxStringLength) {
-
         JakartaMultiPartRequest jak = new JakartaMultiPartRequest();
         jak.setMaxSize(String.valueOf(maxsize));
         jak.setMaxFileSize(String.valueOf(maxfilesize));
         jak.setMaxFiles(String.valueOf(maxfiles));
         jak.setMaxStringLength(String.valueOf(maxStringLength));
+        jak.setDefaultEncoding(StandardCharsets.UTF_8.name());
         return new MultiPartRequestWrapper(jak, req, tempDir.getAbsolutePath(), new DefaultLocaleProvider());
     }
 
@@ -618,11 +617,6 @@ public class FileUploadInterceptorTest extends StrutsInternalTestCase {
     }
 
     public static class MyFileupAction extends ActionSupport {
-
-        private static final long serialVersionUID = 6255238895447968889L;
-
-        // no methods
     }
 
-
 }

core/src/test/resources/log4j2.xml

@@ -29,5 +29,6 @@
         <Root level="info">
             <AppenderRef ref="STDOUT"/>
         </Root>
+        <Logger name="org.apache.struts2.dispatcher.multipart" level="debug"/>
     </Loggers>
 </Configuration>

pom.xml

@@ -818,8 +818,8 @@
             </dependency>
             <dependency>
                 <groupId>org.apache.commons</groupId>
-                <artifactId>commons-fileupload2-jakarta</artifactId>
-                <version>2.0.0-M1</version>
+                <artifactId>commons-fileupload2-jakarta-servlet6</artifactId>
+                <version>2.0.0-M2</version>
             </dependency>
             <dependency>
                 <groupId>commons-io</groupId>