WW-4889 Adds XML handler based on Apache Juneau

plugins/rest/pom.xml

@@ -55,6 +55,18 @@
             <optional>true</optional>
         </dependency>
 
+        <dependency>
+            <groupId>org.apache.juneau</groupId>
+            <artifactId>juneau-marshall</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+        <dependency>
+            <groupId>commons-beanutils</groupId>
+            <artifactId>commons-beanutils</artifactId>
+            <optional>true</optional>
+        </dependency>
+
         <dependency>
             <groupId>mockobjects</groupId>
             <artifactId>mockobjects-core</artifactId>

plugins/rest/src/main/java/org/apache/struts2/rest/handler/JuneauXmlHandler.java

@@ -0,0 +1,81 @@
+/*
+ * 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.rest.handler;
+
+import com.opensymphony.xwork2.ActionInvocation;
+import org.apache.commons.beanutils.BeanUtils;
+import org.apache.juneau.parser.ParseException;
+import org.apache.juneau.serializer.SerializeException;
+import org.apache.juneau.xml.XmlDocSerializer;
+import org.apache.juneau.xml.XmlParser;
+import org.apache.juneau.xml.XmlSerializer;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import java.io.IOException;
+import java.io.Reader;
+import java.io.Writer;
+import java.lang.reflect.InvocationTargetException;
+
+/**
+ * Handles XML content using Apache Juneau
+ * http://juneau.apache.org/#marshall.html
+ */
+public class JuneauXmlHandler extends AbstractContentTypeHandler {
+
+    private static final Logger LOG = LogManager.getLogger(JuneauXmlHandler.class);
+
+    private static final String DEFAULT_CONTENT_TYPE = "application/xml";
+
+    private final XmlParser parser = XmlParser.DEFAULT;
+    private final XmlSerializer serializer = XmlDocSerializer.DEFAULT;
+
+    public void toObject(ActionInvocation invocation, Reader in, Object target) throws IOException {
+        LOG.debug("Converting input into an object of: {}", target.getClass().getName());
+        try {
+            Object result = parser.parse(in, target.getClass());
+            BeanUtils.copyProperties(target, result);
+        } catch (ParseException | IllegalAccessException | InvocationTargetException e) {
+            throw new IOException(e);
+        }
+    }
+
+    public String fromObject(ActionInvocation invocation, Object obj, String resultCode, Writer stream) throws IOException {
+        LOG.debug("Converting an object of {} into string", obj.getClass().getName());
+        try {
+            serializer
+                .builder()
+                .locale(invocation.getInvocationContext().getLocale())
+                .build()
+                .serialize(obj, stream);
+            return null;
+        } catch (SerializeException e) {
+            throw new IOException(e);
+        }
+    }
+
+    public String getContentType() {
+        return DEFAULT_CONTENT_TYPE;
+    }
+
+    public String getExtension() {
+        return "xml";
+    }
+
+}

plugins/rest/src/test/java/org/apache/struts2/rest/handler/JuneauXmlHandlerTest.java

@@ -0,0 +1,93 @@
+/*
+ * 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.rest.handler;
+
+import com.opensymphony.xwork2.ActionContext;
+import com.opensymphony.xwork2.ActionInvocation;
+import com.opensymphony.xwork2.XWorkTestCase;
+import com.opensymphony.xwork2.mock.MockActionInvocation;
+
+import java.io.Reader;
+import java.io.StringReader;
+import java.io.StringWriter;
+import java.io.Writer;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Locale;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class JuneauXmlHandlerTest extends XWorkTestCase {
+
+    private String xml;
+    private JuneauXmlHandler handler;
+    private ActionInvocation ai;
+
+    public void setUp() throws Exception {
+        super.setUp();
+        xml = "<object>" +
+            "<name>Jan</name>" +
+            "<age>12</age>" +
+            "<parents>" +
+            "<string>Adam</string>" +
+            "<string>Ewa</string>" +
+            "</parents>" +
+            "</object>";
+        handler = new JuneauXmlHandler();
+        ai = new MockActionInvocation();
+        ActionContext context = new ActionContext(new HashMap<String, Object>());
+        context.setLocale(Locale.US);
+        ((MockActionInvocation) ai).setInvocationContext(context);
+    }
+
+    public void testObjectToXml() throws Exception {
+        // given
+        SimpleBean obj = new SimpleBean();
+        obj.setName("Jan");
+        obj.setAge(12L);
+        obj.setParents(Arrays.asList("Adam", "Ewa"));
+
+        // when
+        Writer stream = new StringWriter();
+        handler.fromObject(ai, obj, null, stream);
+
+        // then
+        stream.flush();
+        assertEquals(xml, stream.toString());
+    }
+
+    public void testXmlToObject() throws Exception {
+        // given
+        SimpleBean obj = new SimpleBean();
+
+        // when
+        Reader in = new StringReader(xml);
+        handler.toObject(ai, in, obj);
+
+        // then
+        assertNotNull(obj);
+        assertEquals(obj.getName(), "Jan");
+        assertEquals(obj.getAge().longValue(), 12L);
+        assertNotNull(obj.getParents());
+        assertThat(obj.getParents())
+                .hasSize(2)
+                .containsExactly("Adam", "Ewa");
+    }
+
+}

pom.xml

@@ -1072,6 +1072,12 @@
                 <version>${jackson.version}</version>
             </dependency>
 
+            <dependency>
+                <groupId>org.apache.juneau</groupId>
+                <artifactId>juneau-marshall</artifactId>
+                <version>7.2.2</version>
+            </dependency>
+
             <!-- CDI & Weld -->
             <dependency>
                 <groupId>javax.enterprise</groupId>