INT-3193: Add ObjectToMapTransformer flatten attr

JIRA: https://jira.springsource.org/browse/INT-3193

spring-integration-core/src/main/java/org/springframework/integration/config/xml/ObjectToMapTransformerParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2010 the original author or authors.
+ * Copyright 2002-2013 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.
@@ -22,6 +22,7 @@ import org.w3c.dom.Element;
 
 /**
  * @author Oleg Zhurakousky
+ * @author Mauro Franceschini
  * @since 2.0
  */
 public class ObjectToMapTransformerParser extends AbstractTransformerParser {
@@ -33,5 +34,6 @@ public class ObjectToMapTransformerParser extends AbstractTransformerParser {
 
 	@Override
 	protected void parseTransformer(Element element, ParserContext parserContext, BeanDefinitionBuilder builder) {
+        IntegrationNamespaceUtils.setValueIfAttributeDefined(builder, element, "flatten", "shouldFlattenKeys");
 	}
 }

spring-integration-core/src/main/resources/org/springframework/integration/config/xml/spring-integration-3.0.xsd

@@ -2169,6 +2169,15 @@
 			<xsd:complexContent>
 				<xsd:extension base="specialized-transformer-type">
 					<xsd:attributeGroup ref="inputOutputChannelGroup" />
+					<xsd:attribute name="flatten" type="xsd:string" default="true">
+						<xsd:annotation>
+							<xsd:documentation>
+								Specifies if the result Map of Maps should be transformed further to flat keys of
+								object's property paths.
+								Default is 'true'.
+							</xsd:documentation>
+						</xsd:annotation>
+					</xsd:attribute>
 				</xsd:extension>
 			</xsd:complexContent>
 		</xsd:complexType>

spring-integration-core/src/test/java/org/springframework/integration/config/xml/ObjectToMapTransformerParserTests-context.xml

@@ -15,4 +15,12 @@
 
 	<object-to-map-transformer input-channel="directInput" output-channel="output"/>
 
+	<channel id="nestedInput"/>
+
+	<channel id="nestedOutput">
+		<queue capacity="1"/>
+	</channel>
+
+	<object-to-map-transformer input-channel="nestedInput" output-channel="nestedOutput" flatten="false"/>
+
 </beans:beans>

spring-integration-core/src/test/java/org/springframework/integration/config/xml/ObjectToMapTransformerParserTests.java

@@ -21,6 +21,7 @@ import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.hamcrest.Matchers;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -40,10 +41,12 @@ import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertThat;
 
 /**
  * @author Oleg Zhurakousky
  * @author Gunnar Hillert
+ * @author Mauro Franceschini
  */
 @ContextConfiguration
 @RunWith(SpringJUnit4ClassRunner.class)
@@ -57,6 +60,14 @@ public class ObjectToMapTransformerParserTests {
 	@Qualifier("output")
 	private PollableChannel output;
 
+    @Autowired
+    @Qualifier("nestedInput")
+    private MessageChannel nestedInput;
+
+    @Autowired
+    @Qualifier("nestedOutput")
+    private PollableChannel nestedOutput;
+
 
 	@SuppressWarnings("unchecked")
 	@Test
@@ -90,6 +101,23 @@ public class ObjectToMapTransformerParserTests {
 		directInput.send(message);
 	}
 
+	@Test
+	public void testObjectToNotFlattenedMapTransformer(){
+		Employee employee = this.buildEmployee();
+
+		Message<Employee> message = MessageBuilder.withPayload(employee).build();
+		nestedInput.send(message);
+
+		@SuppressWarnings("unchecked")
+		Message<Map<String, Object>> outputMessage = (Message<Map<String, Object>>) nestedOutput.receive(1000);
+		Map<String, Object> transformedMap = outputMessage.getPayload();
+		assertNotNull(outputMessage.getPayload());
+
+		assertEquals(employee.getCompanyName(), transformedMap.get("companyName"));
+		assertThat(transformedMap.get("companyAddress"), Matchers.instanceOf(Map.class));
+		assertThat(transformedMap.get("departments"), Matchers.instanceOf(List.class));
+	}
+
 	@SuppressWarnings({ "unchecked", "rawtypes" })
 	public Employee buildEmployee(){
 		Address companyAddress = new Address();

src/reference/docbook/transformer.xml

@@ -184,10 +184,33 @@ public class Kid {
    // setters and getters are omitted
 }]]></programlisting>
     </para>
+	<para>
+	If you need to create a "structured" map, you can provide the 'flatten' attribute. The default value for this
+	attribute is 'true' meaning the default behavior; if you provide a 'false' value, then the structure will be a
+	map of maps.
+	</para>
+	<para>
+	For example:
+	<programlisting language="java"><![CDATA[public class Parent {
+	private Child child;
+	private String name;
+	// setters and getters are omitted
+}
+
+public class Child {
+	private String name;
+	private List<String> nickNames;
+	// setters and getters are omitted
+}]]></programlisting>
+	... will be transformed to a Map which looks like this:
+	<code>{name=George, child={name=Jenna, nickNames=[Bimbo, ...]}}</code>
+	</para>
     <para>
     To configure these transformers, Spring Integration provides namespace support
     Object-to-Map:
 <programlisting language="xml"><![CDATA[<int:object-to-map-transformer input-channel="directInput" output-channel="output"/>]]></programlisting>
+  or
+<programlisting language="xml"><![CDATA[<int:object-to-map-transformer input-channel="directInput" output-channel="output" flatten="false"/>]]></programlisting>
     Map-to-Object
 <programlisting language="xml"><![CDATA[<int:map-to-object-transformer input-channel="input" 
                          output-channel="output"