Reorganized handler packaging and added AbstractMessageHandlerAdapter

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

@@ -24,7 +24,6 @@ import org.springframework.beans.factory.parsing.BeanComponentDefinition;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
-import org.springframework.integration.endpoint.annotation.MessageEndpointAnnotationPostProcessor;
 
 /**
  * Parser for the <em>annotation-driven</em> element of the integration

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

@@ -23,8 +23,8 @@ import org.springframework.beans.factory.support.DefaultBeanNameGenerator;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.integration.endpoint.GenericMessageEndpoint;
 import org.springframework.integration.endpoint.InboundMethodInvokingChannelAdapter;
-import org.springframework.integration.endpoint.MessageHandlerAdapter;
 import org.springframework.integration.endpoint.OutboundMethodInvokingChannelAdapter;
+import org.springframework.integration.handler.DefaultMessageHandlerAdapter;
 import org.springframework.util.Assert;
 
 /**
@@ -47,7 +47,7 @@ public class ComponentConfigurer {
 
 	public String serviceActivator(String inputChannel, String outputChannel, String objectRef, String method) {
 		RootBeanDefinition endpointDef = new RootBeanDefinition(GenericMessageEndpoint.class);
-		RootBeanDefinition adapterDef = new RootBeanDefinition(MessageHandlerAdapter.class);
+		RootBeanDefinition adapterDef = new RootBeanDefinition(DefaultMessageHandlerAdapter.class);
 		adapterDef.getPropertyValues().addPropertyValue("object", new RuntimeBeanReference(objectRef));
 		adapterDef.getPropertyValues().addPropertyValue("method", method);
 		String adapterName = beanNameGenerator.generateBeanName(adapterDef, this.registry);

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

@@ -28,7 +28,7 @@ import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.integration.bus.ConsumerPolicy;
 import org.springframework.integration.endpoint.GenericMessageEndpoint;
-import org.springframework.integration.endpoint.MessageHandlerAdapter;
+import org.springframework.integration.handler.DefaultMessageHandlerAdapter;
 import org.springframework.util.StringUtils;
 
 /**
@@ -82,7 +82,7 @@ public class EndpointParser implements BeanDefinitionParser {
 		if (StringUtils.hasText(handlerRef)) {
 			String handlerMethod = element.getAttribute(HANDLER_METHOD_ATTRIBUTE);
 			if (StringUtils.hasText(handlerMethod)) {
-				BeanDefinition handlerAdapterDef = new RootBeanDefinition(MessageHandlerAdapter.class);
+				BeanDefinition handlerAdapterDef = new RootBeanDefinition(DefaultMessageHandlerAdapter.class);
 				handlerAdapterDef.getPropertyValues().addPropertyValue(OBJECT_PROPERTY, new RuntimeBeanReference(handlerRef));
 				handlerAdapterDef.getPropertyValues().addPropertyValue(METHOD_PROPERTY, handlerMethod);
 				String adapterBeanName = parserContext.getReaderContext().generateBeanName(handlerAdapterDef);

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

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.integration.endpoint.annotation;
+package org.springframework.integration.config;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
@@ -34,8 +34,14 @@ import org.springframework.integration.bus.MessageBus;
 import org.springframework.integration.endpoint.GenericMessageEndpoint;
 import org.springframework.integration.endpoint.InboundMethodInvokingChannelAdapter;
 import org.springframework.integration.endpoint.OutboundMethodInvokingChannelAdapter;
+import org.springframework.integration.endpoint.annotation.DefaultOutput;
+import org.springframework.integration.endpoint.annotation.MessageEndpoint;
+import org.springframework.integration.endpoint.annotation.Polled;
 import org.springframework.integration.handler.MessageHandler;
 import org.springframework.integration.handler.MessageHandlerChain;
+import org.springframework.integration.handler.annotation.AnnotationHandlerCreator;
+import org.springframework.integration.handler.annotation.DefaultAnnotationHandlerCreator;
+import org.springframework.integration.handler.annotation.Handler;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.StringUtils;

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

@@ -28,8 +28,8 @@ import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.integration.bus.MessageBus;
 import org.springframework.integration.endpoint.GenericMessageEndpoint;
-import org.springframework.integration.endpoint.MessageHandlerAdapter;
 import org.springframework.integration.endpoint.annotation.Subscriber;
+import org.springframework.integration.handler.DefaultMessageHandlerAdapter;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ReflectionUtils;
@@ -81,7 +81,7 @@ public class SubscriberAnnotationPostProcessor implements BeanPostProcessor {
 				Annotation annotation = method.getAnnotation(subscriberAnnotationType);
 				if (annotation != null) {
 					String channelName = (String) AnnotationUtils.getValue(annotation, channelNameAttribute);
-					MessageHandlerAdapter adapter = new MessageHandlerAdapter();
+					DefaultMessageHandlerAdapter adapter = new DefaultMessageHandlerAdapter();
 					adapter.setMethod(method.getName());
 					adapter.setObject(bean);
 					adapter.afterPropertiesSet();

spring-integration-core/src/main/java/org/springframework/integration/handler/AbstractMessageHandlerAdapter.java

@@ -14,25 +14,27 @@
  * limitations under the License.
  */
 
-package org.springframework.integration.endpoint;
+package org.springframework.integration.handler;
 
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.core.Ordered;
-import org.springframework.integration.handler.MessageHandler;
+import org.springframework.integration.endpoint.SimpleMethodInvoker;
 import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageMapper;
 import org.springframework.integration.message.SimplePayloadMessageMapper;
 import org.springframework.util.Assert;
 
 /**
- * An implementation of {@link MessageHandler} that invokes the specified method
- * on the provided target object. It then uses a {@link MessageMapper} strategy
- * for converting the object to a {@link Message}. If the method has a non-null
- * return value, a reply message will be generated by the mapper.
+ * Base implementation of the {@link MessageHandler} interface that creates an
+ * invoker for the specified method and target object. It also accepts an
+ * implementation of the {@link MessageMapper} strategy which it exposes to
+ * subclasses for converting the {@link Message} to an object. Likewise, if the
+ * method has a non-null return value, a reply message will be generated by the
+ * mapper.
  * 
  * @author Mark Fisher
  */
-public class MessageHandlerAdapter<T> implements MessageHandler, Ordered, InitializingBean {
+public abstract class AbstractMessageHandlerAdapter<T> implements MessageHandler, Ordered, InitializingBean {
 
 	private T object;
 
@@ -50,11 +52,28 @@ public class MessageHandlerAdapter<T> implements MessageHandler, Ordered, Initia
 		this.object = object;
 	}
 
+	protected Object getObject() {
+		return this.object;
+	}
+
 	public void setMethod(String method) {
 		Assert.notNull(method, "'method' must not be null");
 		this.method = method;
 	}
 
+	public String getMethod() {
+		return this.method;
+	}
+
+	public void setMapper(MessageMapper mapper) {
+		Assert.notNull(mapper, "'mapper' must not be null");
+		this.mapper = mapper;
+	}
+
+	protected MessageMapper getMapper() {
+		return this.mapper;
+	}
+
 	public void setOrder(int order) {
 		this.order = order;
 	}
@@ -68,11 +87,21 @@ public class MessageHandlerAdapter<T> implements MessageHandler, Ordered, Initia
 	}
 
 	public Message handle(Message message) {
-		Object result = this.invoker.invokeMethod(this.mapper.fromMessage(message));
+		Object result = this.doHandle(message, invoker);
 		if (result != null) {
+			if (result instanceof Message) {
+				return (Message) result;
+			}
 			return this.mapper.toMessage(result);
 		}
 		return null;
 	}
 
+	/**
+	 * Subclasses must implement this method. The invoker has been created for
+	 * the provided target object and method. May return an object of type
+	 * {@link Message}, else rely on the message mapper to convert.
+	 */
+	protected abstract Object doHandle(Message message, SimpleMethodInvoker invoker);
+
 }

spring-integration-core/src/main/java/org/springframework/integration/handler/DefaultMessageHandlerAdapter.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2002-2007 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.integration.handler;
+
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.core.Ordered;
+import org.springframework.integration.endpoint.SimpleMethodInvoker;
+import org.springframework.integration.message.Message;
+import org.springframework.integration.message.MessageMapper;
+
+/**
+ * An implementation of {@link MessageHandler} that invokes the specified method
+ * on the provided target object. It then uses a {@link MessageMapper} strategy
+ * for converting the object to a {@link Message}. If the method has a non-null
+ * return value, a reply message will be generated by the mapper.
+ * 
+ * @author Mark Fisher
+ */
+public class DefaultMessageHandlerAdapter<T> extends AbstractMessageHandlerAdapter<T> 
+		implements Ordered, InitializingBean {
+
+	public Object doHandle(Message message, SimpleMethodInvoker invoker) {
+		return invoker.invokeMethod(this.getMapper().fromMessage(message));
+	}
+
+}

spring-integration-core/src/main/java/org/springframework/integration/handler/annotation/AnnotationHandlerCreator.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.integration.endpoint.annotation;
+package org.springframework.integration.handler.annotation;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;

spring-integration-core/src/main/java/org/springframework/integration/handler/annotation/DefaultAnnotationHandlerCreator.java

@@ -14,19 +14,19 @@
  * limitations under the License.
  */
 
-package org.springframework.integration.endpoint.annotation;
+package org.springframework.integration.handler.annotation;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.core.annotation.Order;
-import org.springframework.integration.endpoint.MessageHandlerAdapter;
 import org.springframework.integration.handler.MessageHandler;
+import org.springframework.integration.handler.DefaultMessageHandlerAdapter;
 
 /**
  * Default implementation of the handler creator strategy that creates a
- * {@link MessageHandlerAdapter} for the provided object and method. This
+ * {@link DefaultMessageHandlerAdapter} for the provided object and method. This
  * version does not even consider the annotation itself. It does however
  * respect an {@link Order} annotation if present.
  * 
@@ -35,7 +35,7 @@ import org.springframework.integration.handler.MessageHandler;
 public class DefaultAnnotationHandlerCreator implements AnnotationHandlerCreator {
 
 	public MessageHandler createHandler(Object object, Method method, Annotation annotation) {
-		MessageHandlerAdapter<Object> adapter = new MessageHandlerAdapter<Object>();
+		DefaultMessageHandlerAdapter<Object> adapter = new DefaultMessageHandlerAdapter<Object>();
 		adapter.setObject(object);
 		adapter.setMethod(method.getName());
 		Order orderAnnotation = (Order) AnnotationUtils.getAnnotation(method, Order.class);

spring-integration-core/src/main/java/org/springframework/integration/handler/annotation/Handler.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.integration.endpoint.annotation;
+package org.springframework.integration.handler.annotation;
 
 import java.lang.annotation.Documented;
 import java.lang.annotation.ElementType;
@@ -23,6 +23,8 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.springframework.integration.endpoint.annotation.MessageEndpoint;
+
 /**
  * Indicates that a method is capable of handling a message or message payload.
  * The method may only accept a single parameter, and the enclosing class should