Merge pull request #8125 from eugenp/revert-8119-BAEL-3275-2

Revert "BAEL-3275: Using blocking queue for pub-sub"

xml/src/main/java/com/baeldung/xmlhtml/Application.java

@@ -0,0 +1,10 @@
+package com.baeldung.xmlhtml;
+
+import com.baeldung.xmlhtml.helpers.XMLRunner;
+
+public class Application {
+
+    public static void main(String[] args) {
+        XMLRunner.doWork();
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/Constants.java

@@ -0,0 +1,22 @@
+package com.baeldung.xmlhtml;
+
+public class Constants {
+
+    public static final String XML_FILE_IN = "src/main/resources/xml/in.xml";
+    public static final String JAXB_FILE_OUT = "src/main/resources/xml/jaxb.html";
+    public static final String JAXP_FILE_OUT = "src/main/resources/xml/jaxp.html";
+    public static final String STAX_FILE_OUT = "src/main/resources/xml/stax.html";
+
+    public static final String EXCEPTION_ENCOUNTERED = "Generic exception! Error: ";
+
+    public static final String LINE_BREAK = System.getProperty("line.separator");
+    public static final String WHITE_SPACE = " ";
+
+    public static final String DOCUMENT_START = "Document parsing has begun!";
+    public static final String DOCUMENT_END = "Document parsing has ended!";
+    public static final String ELEMENT_START = "Element parsing has begun!";
+    public static final String ELEMENT_END = "Element parsing has ended!";
+
+    public static final String BREAK = "\n";
+    public static final String TAB = "\t";
+}

xml/src/main/java/com/baeldung/xmlhtml/freemarker/FreemarkerTransformer.java

@@ -0,0 +1,41 @@
+package com.baeldung.xmlhtml.freemarker;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import freemarker.template.Configuration;
+import freemarker.template.Template;
+import freemarker.template.TemplateException;
+import freemarker.template.TemplateExceptionHandler;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.File;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+
+public class FreemarkerTransformer {
+    private StaxTransformer staxTransformer;
+    private String templateDirectory;
+    private String templateFile;
+
+    public FreemarkerTransformer(StaxTransformer staxTransformer, String templateDirectory, String templateFile) {
+        this.staxTransformer = staxTransformer;
+        this.templateDirectory = templateDirectory;
+        this.templateFile = templateFile;
+    }
+
+    public String html() throws IOException, TemplateException {
+        Configuration cfg = new Configuration(Configuration.VERSION_2_3_29);
+        cfg.setDirectoryForTemplateLoading(new File(templateDirectory));
+        cfg.setDefaultEncoding(StandardCharsets.UTF_8.toString());
+        cfg.setTemplateExceptionHandler(TemplateExceptionHandler.RETHROW_HANDLER);
+        cfg.setLogTemplateExceptions(false);
+        cfg.setWrapUncheckedExceptions(true);
+        cfg.setFallbackOnNullLoopVariable(false);
+        Template temp = cfg.getTemplate(templateFile);
+        try (Writer output = new StringWriter()) {
+            temp.process(staxTransformer.getMap(), output);
+            return output.toString();
+        }
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/helpers/XMLRunner.java

@@ -0,0 +1,12 @@
+package com.baeldung.xmlhtml.helpers;
+
+
+import com.baeldung.xmlhtml.helpers.jaxb.JAXBHelper;
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+
+public class XMLRunner {
+
+    public static void doWork() {
+        JAXBHelper.example();
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/helpers/jaxb/JAXBHelper.java

@@ -0,0 +1,77 @@
+package com.baeldung.xmlhtml.helpers.jaxb;
+
+import com.baeldung.xmlhtml.pojo.jaxb.html.ExampleHTML;
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.Body;
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.CustomElement;
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.Meta;
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.NestedElement;
+import com.baeldung.xmlhtml.pojo.jaxb.xml.XMLExample;
+
+import javax.xml.bind.JAXBContext;
+import javax.xml.bind.Marshaller;
+import javax.xml.bind.Unmarshaller;
+
+import java.io.File;
+
+import static com.baeldung.xmlhtml.Constants.*;
+
+public class JAXBHelper {
+
+    private static void print(String xmlContent) {
+        System.out.println(xmlContent);
+    }
+
+    private static Unmarshaller getContextUnmarshaller(Class clazz) {
+        Unmarshaller unmarshaller = null;
+        try {
+            JAXBContext context = JAXBContext.newInstance(clazz);
+            unmarshaller = context.createUnmarshaller();
+        } catch (Exception ex) {
+            System.out.println(EXCEPTION_ENCOUNTERED + ex);
+        }
+        return unmarshaller;
+    }
+
+    private static Marshaller getContextMarshaller(Class clazz) {
+        Marshaller marshaller = null;
+        try {
+            JAXBContext context = JAXBContext.newInstance(clazz);
+            marshaller = context.createMarshaller();
+            marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
+            marshaller.setProperty("jaxb.fragment", Boolean.TRUE);
+        } catch (Exception ex) {
+            System.out.println(EXCEPTION_ENCOUNTERED + ex);
+        }
+        return marshaller;
+    }
+
+    public static void example() {
+        try {
+            XMLExample xml = (XMLExample) JAXBHelper.getContextUnmarshaller(XMLExample.class).unmarshal(new File(XML_FILE_IN));
+            JAXBHelper.print(xml.toString());
+            ExampleHTML html = new ExampleHTML();
+
+            Body body = new Body();
+            CustomElement customElement = new CustomElement();
+            NestedElement nested = new NestedElement();
+            CustomElement child = new CustomElement();
+
+            customElement.setValue("descendantOne: " + xml.getAncestor().getDescendantOne().getValue());
+            child.setValue("descendantThree: " + xml.getAncestor().getDescendantTwo().getDescendantThree().getValue());
+            nested.setCustomElement(child);
+
+            body.setCustomElement(customElement);
+            body.setNestedElement(nested);
+
+            Meta meta = new Meta();
+            meta.setTitle("example");
+            html.getHead().add(meta);
+            html.setBody(body);
+
+            JAXBHelper.getContextMarshaller(ExampleHTML.class).marshal(html, new File(JAXB_FILE_OUT));
+
+        } catch (Exception ex) {
+            System.out.println(EXCEPTION_ENCOUNTERED + ex);
+        }
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/jaxp/JaxpTransformer.java

@@ -0,0 +1,103 @@
+package com.baeldung.xmlhtml.jaxp;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.xml.sax.SAXException;
+
+import javax.xml.XMLConstants;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class JaxpTransformer {
+
+    private Document input;
+    private DocumentBuilderFactory factory;
+
+    public JaxpTransformer(String resourcePath) throws ParserConfigurationException, IOException, SAXException {
+        // 1- Build the doc from the XML file
+        factory = DocumentBuilderFactory.newInstance();
+        factory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        factory.setFeature("http://apache.org/xml/features/disallow-doctype-decl", true);
+        input = factory
+          .newDocumentBuilder()
+          .parse(resourcePath);
+    }
+
+    public String html() throws ParserConfigurationException, TransformerException, IOException {
+        Element xml = input.getDocumentElement();
+        Document doc = factory
+          .newDocumentBuilder()
+          .newDocument();
+        //Build Map
+        Map<String, String> map = buildMap(xml);
+        //Head
+        Element html = doc.createElement("html");
+        html.setAttribute("lang", "en");
+        Element head = buildHead(map, doc);
+        html.appendChild(head);
+        //Body
+        Element body = buildBody(map, doc);
+        html.appendChild(body);
+        doc.appendChild(html);
+        return String.format("<!DOCTYPE html>%n%s", applyTransformation(doc));
+    }
+
+    private String applyTransformation(Document doc) throws TransformerException, IOException {
+        TransformerFactory transformerFactory = TransformerFactory.newInstance();
+        transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
+        transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_DTD, "");
+        transformerFactory.setAttribute(XMLConstants.ACCESS_EXTERNAL_STYLESHEET, "");
+        try (Writer output = new StringWriter()) {
+            Transformer transformer = transformerFactory.newTransformer();
+            transformer.transform(new DOMSource(doc), new StreamResult(output));
+            return output.toString();
+        }
+    }
+
+    private Map<String, String> buildMap(Element xml) {
+        Map<String, String> map = new HashMap<>();
+        map.put("heading", xml
+          .getElementsByTagName("heading")
+          .item(0)
+          .getTextContent());
+        map.put("from", String.format("from: %s", xml
+          .getElementsByTagName("from")
+          .item(0)
+          .getTextContent()));
+        map.put("content", xml
+          .getElementsByTagName("content")
+          .item(0)
+          .getTextContent());
+        return map;
+    }
+
+    private Element buildHead(Map<String, String> map, Document doc) {
+        Element head = doc.createElement("head");
+        Element title = doc.createElement("title");
+        title.setTextContent(map.get("heading"));
+        head.appendChild(title);
+        return head;
+    }
+
+    private Element buildBody(Map<String, String> map, Document doc) {
+        Element body = doc.createElement("body");
+        Element from = doc.createElement("p");
+        from.setTextContent(map.get("from"));
+        Element success = doc.createElement("p");
+        success.setTextContent(map.get("content"));
+        body.appendChild(from);
+        body.appendChild(success);
+        return body;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/mustache/MustacheTransformer.java

@@ -0,0 +1,31 @@
+package com.baeldung.xmlhtml.mustache;
+
+import com.baeldung.xmlhtml.stax.StaxTransformer;
+import com.github.mustachejava.DefaultMustacheFactory;
+import com.github.mustachejava.Mustache;
+import com.github.mustachejava.MustacheFactory;
+
+import javax.xml.stream.XMLStreamException;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+
+public class MustacheTransformer {
+    private StaxTransformer staxTransformer;
+    private String templateFile;
+
+    public MustacheTransformer(StaxTransformer staxTransformer, String templateFile) {
+        this.staxTransformer = staxTransformer;
+        this.templateFile = templateFile;
+    }
+
+    public String html() throws IOException {
+        MustacheFactory mf = new DefaultMustacheFactory();
+        Mustache mustache = mf.compile(templateFile);
+        try (Writer output = new StringWriter()) {
+            mustache.execute(output, staxTransformer.getMap());
+            output.flush();
+            return output.toString();
+        }
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/html/ExampleHTML.java

@@ -0,0 +1,38 @@
+package com.baeldung.xmlhtml.pojo.jaxb.html;
+
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.Body;
+import com.baeldung.xmlhtml.pojo.jaxb.html.elements.Meta;
+
+import javax.xml.bind.annotation.*;
+import java.util.ArrayList;
+import java.util.List;
+
+@XmlType(propOrder = {"head", "body"})
+@XmlRootElement(name = "html")
+public class ExampleHTML {
+
+    private List<Meta> head = new ArrayList<>();
+
+    private Body body;
+
+    public ExampleHTML() { }
+
+    public List<Meta> getHead() {
+        return head;
+    }
+
+    @XmlElementWrapper(name = "head")
+    @XmlElement(name = "meta")
+    public void setHead(List<Meta> head) {
+        this.head = head;
+    }
+
+    public Body getBody() {
+        return body;
+    }
+
+    @XmlElement(name = "body")
+    public void setBody(Body body) {
+        this.body = body;
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/html/elements/Body.java

@@ -0,0 +1,29 @@
+package com.baeldung.xmlhtml.pojo.jaxb.html.elements;
+
+import javax.xml.bind.annotation.XmlElement;
+
+public class Body {
+
+    private CustomElement customElement;
+
+    public CustomElement getCustomElement() {
+        return customElement;
+    }
+
+    @XmlElement(name = "p")
+    public void setCustomElement(CustomElement customElement) {
+        this.customElement = customElement;
+    }
+
+    private NestedElement nestedElement;
+
+    public NestedElement getNestedElement() {
+        return nestedElement;
+    }
+
+    @XmlElement(name = "div")
+    public void setNestedElement(NestedElement nestedElement) {
+        this.nestedElement = nestedElement;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/html/elements/CustomElement.java

@@ -0,0 +1,18 @@
+package com.baeldung.xmlhtml.pojo.jaxb.html.elements;
+
+import javax.xml.bind.annotation.XmlValue;
+
+public class CustomElement {
+
+    private String value;
+
+    @XmlValue
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/html/elements/Meta.java

@@ -0,0 +1,30 @@
+package com.baeldung.xmlhtml.pojo.jaxb.html.elements;
+
+import javax.xml.bind.annotation.XmlAttribute;
+import javax.xml.bind.annotation.XmlValue;
+
+public class Meta {
+
+    private String title;
+
+    public String getTitle() {
+        return title;
+    }
+
+    @XmlAttribute(name = "title")
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    private String value;
+
+    @XmlValue
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/html/elements/NestedElement.java

@@ -0,0 +1,17 @@
+package com.baeldung.xmlhtml.pojo.jaxb.html.elements;
+
+import javax.xml.bind.annotation.XmlElement;
+
+public class NestedElement {
+
+    private CustomElement customElement;
+
+    public CustomElement getCustomElement() {
+        return customElement;
+    }
+
+    @XmlElement(name = "p")
+    public void setCustomElement(CustomElement customElement) {
+        this.customElement = customElement;
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/xml/XMLExample.java

@@ -0,0 +1,21 @@
+package com.baeldung.xmlhtml.pojo.jaxb.xml;
+
+import com.baeldung.xmlhtml.pojo.jaxb.xml.elements.Ancestor;
+
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlRootElement;
+
+@XmlRootElement(name = "xmlexample")
+public class XMLExample {
+
+    private Ancestor ancestor;
+
+    @XmlElement(name = "ancestor")
+    public void setAncestor(Ancestor ancestor) {
+        this.ancestor = ancestor;
+    }
+
+    public Ancestor getAncestor() {
+        return ancestor;
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/xml/elements/Ancestor.java

@@ -0,0 +1,28 @@
+package com.baeldung.xmlhtml.pojo.jaxb.xml.elements;
+
+import javax.xml.bind.annotation.XmlElement;
+
+public class Ancestor {
+
+    private DescendantOne descendantOne;
+    private DescendantTwo descendantTwo;
+
+    public DescendantOne getDescendantOne() {
+        return descendantOne;
+    }
+
+    @XmlElement(name = "descendantOne")
+    public void setDescendantOne(DescendantOne descendantOne) {
+        this.descendantOne = descendantOne;
+    }
+
+    public DescendantTwo getDescendantTwo() {
+        return descendantTwo;
+    }
+
+    @XmlElement(name = "descendantTwo")
+    public void setDescendantTwo(DescendantTwo descendantTwo) {
+        this.descendantTwo = descendantTwo;
+    }
+}
+

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/xml/elements/DescendantOne.java

@@ -0,0 +1,19 @@
+package com.baeldung.xmlhtml.pojo.jaxb.xml.elements;
+
+import javax.xml.bind.annotation.XmlValue;
+
+public class DescendantOne {
+
+    private String value;
+
+    @XmlValue
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+}
+

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/xml/elements/DescendantThree.java

@@ -0,0 +1,18 @@
+package com.baeldung.xmlhtml.pojo.jaxb.xml.elements;
+
+import javax.xml.bind.annotation.XmlValue;
+
+public class DescendantThree {
+
+    private String value;
+
+    @XmlValue
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+}

xml/src/main/java/com/baeldung/xmlhtml/pojo/jaxb/xml/elements/DescendantTwo.java

@@ -0,0 +1,17 @@
+package com.baeldung.xmlhtml.pojo.jaxb.xml.elements;
+
+import javax.xml.bind.annotation.XmlElement;
+
+public class DescendantTwo {
+
+    private DescendantThree descendantThree;
+
+    public DescendantThree getDescendantThree() {
+        return descendantThree;
+    }
+
+    @XmlElement(name = "descendantThree")
+    public void setDescendant(DescendantThree descendantThree) {
+        this.descendantThree = descendantThree;
+    }
+}

xml/src/main/java/com/baeldung/xmlhtml/stax/StaxTransformer.java

@@ -0,0 +1,99 @@
+package com.baeldung.xmlhtml.stax;
+
+import javax.xml.stream.*;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.HashMap;
+import java.util.Map;
+
+public class StaxTransformer {
+
+    private Map<String, String> map;
+
+    public StaxTransformer(String resourcePath) throws IOException, XMLStreamException {
+        XMLInputFactory factory = XMLInputFactory.newInstance();
+        factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, Boolean.FALSE);
+        factory.setProperty(XMLInputFactory.SUPPORT_DTD, Boolean.FALSE);
+        XMLStreamReader input = null;
+        try (FileInputStream file = new FileInputStream(resourcePath)) {
+            input = factory.createXMLStreamReader(file);
+            map = buildMap(input);
+        } finally {
+            if (input != null) {
+                input.close();
+            }
+        }
+    }
+
+    public String html() throws XMLStreamException, IOException {
+        try (Writer output = new StringWriter()) {
+            XMLStreamWriter writer = XMLOutputFactory
+              .newInstance()
+              .createXMLStreamWriter(output);
+            //Head
+            writer.writeDTD("<!DOCTYPE html>");
+            writer.writeCharacters(String.format("%n"));
+            writer.writeStartElement("html");
+            writer.writeAttribute("lang", "en");
+            writer.writeCharacters(String.format("%n"));
+            writer.writeStartElement("head");
+            writer.writeCharacters(String.format("%n"));
+            writer.writeDTD("<META http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">");
+            writer.writeCharacters(String.format("%n"));
+            writer.writeStartElement("title");
+            writer.writeCharacters(map.get("heading"));
+            writer.writeEndElement();
+            writer.writeCharacters(String.format("%n"));
+            writer.writeEndElement();
+            writer.writeCharacters(String.format("%n"));
+            //Body
+            writer.writeStartElement("body");
+            writer.writeCharacters(String.format("%n"));
+            writer.writeStartElement("p");
+            writer.writeCharacters(map.get("from"));
+            writer.writeEndElement();
+            writer.writeCharacters(String.format("%n"));
+            writer.writeStartElement("p");
+            writer.writeCharacters(map.get("content"));
+            writer.writeEndElement();
+            writer.writeCharacters(String.format("%n"));
+            writer.writeEndElement();
+            writer.writeCharacters(String.format("%n"));
+            writer.writeEndDocument();
+            writer.writeCharacters(String.format("%n"));
+            writer.flush();
+            return output.toString();
+        }
+    }
+
+    private Map<String, String> buildMap(XMLStreamReader input) throws XMLStreamException {
+        Map<String, String> tempMap = new HashMap<>();
+        while (input.hasNext()) {
+            input.next();
+            if (input.isStartElement()) {
+                if (input
+                  .getLocalName()
+                  .equals("heading")) {
+                    tempMap.put("heading", input.getElementText());
+                }
+                if (input
+                  .getLocalName()
+                  .equals("from")) {
+                    tempMap.put("from", String.format("from: %s", input.getElementText()));
+                }
+                if (input
+                  .getLocalName()
+                  .equals("content")) {
+                    tempMap.put("content", input.getElementText());
+                }
+            }
+        }
+        return tempMap;
+    }
+
+    public Map<String, String> getMap() {
+        return map;
+    }
+}