Introduce Marshalling MessageConverter

This commit introduces a messaging.converter.MessageConverter that
marshals to/from XML using the abstractions provided in the OXM module.

Issue: SPR-12726

spring-messaging/src/test/java/org/springframework/messaging/converter/MarshallingMessageConverterTests.java

@@ -0,0 +1,101 @@
+/*
+ * Copyright 2002-2015 the original author or authors.
+ *
+ * Licensed 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.springframework.messaging.converter;
+
+import java.io.IOException;
+import java.nio.charset.Charset;
+import javax.xml.bind.annotation.XmlRootElement;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import org.springframework.messaging.Message;
+import org.springframework.messaging.support.MessageBuilder;
+import org.springframework.oxm.jaxb.Jaxb2Marshaller;
+
+import static org.custommonkey.xmlunit.XMLAssert.assertXMLEqual;
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Arjen Poutsma
+ */
+public class MarshallingMessageConverterTests {
+
+	private static Charset UTF_8 = Charset.forName("UTF-8");
+
+
+	private MarshallingMessageConverter converter;
+
+
+	@Before
+	public void createMarshaller() throws Exception {
+		Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
+		marshaller.setClassesToBeBound(MyBean.class);
+		marshaller.afterPropertiesSet();
+
+		converter = new MarshallingMessageConverter(marshaller);
+	}
+	@Test
+	public void fromMessage() throws Exception {
+		String payload = "<myBean><name>Foo</name></myBean>";
+		Message<?> message = MessageBuilder.withPayload(payload.getBytes(UTF_8)).build();
+		MyBean actual = (MyBean) converter.fromMessage(message, MyBean.class);
+
+		assertEquals("Foo", actual.getName());
+	}
+
+	@Test(expected = MessageConversionException.class)
+	public void fromMessageInvalidXml() throws Exception {
+		String payload = "<myBean><name>Foo</name><myBean>";
+		Message<?> message = MessageBuilder.withPayload(payload.getBytes(UTF_8)).build();
+		converter.fromMessage(message, MyBean.class);
+	}
+
+	@Test(expected = MessageConversionException.class)
+	public void fromMessageValidXmlWithUnknownProperty() throws IOException {
+		String payload = "<myBean><age>42</age><myBean>";
+		Message<?> message = MessageBuilder.withPayload(payload.getBytes(UTF_8)).build();
+		MyBean myBean = (MyBean)converter.fromMessage(message, MyBean.class);
+	}
+
+	@Test
+	public void toMessage() throws Exception {
+		MyBean payload = new MyBean();
+		payload.setName("Foo");
+
+		Message<?> message = converter.toMessage(payload, null);
+		String actual = new String((byte[]) message.getPayload(), UTF_8);
+
+		assertXMLEqual("<myBean><name>Foo</name></myBean>", actual);
+	}
+
+
+	@XmlRootElement
+	public static class MyBean {
+
+		private String name;
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+}