INT-2433: Get Rid of MessageProcessors wrapping

Previously, provided `MessageProcessor` to create a `MessageHandler`
for endpoint was wrapped to `MethodInvokingMessageProcessor`,
e.g. `GroovyScriptExecutingMessageProcessor`.

Check the type of provided object in the constructor
of `MethodInvoking*` strategies and use it directly if it is `MessageProcessor`

JIRA: https://jira.springsource.org/browse/INT-2433

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

@@ -34,6 +34,7 @@ import org.springframework.util.StringUtils;
  * @author Mark Fisher
  * @author Alexander Peters
  * @author Gary Russell
+ * @author Artem Bilan
  */
 abstract class AbstractStandardMessageHandlerFactoryBean extends AbstractSimpleMessageHandlerFactoryBean<MessageHandler> {
 
@@ -135,7 +136,7 @@ abstract class AbstractStandardMessageHandlerFactoryBean extends AbstractSimpleM
 	}
 
 	<T> MessageHandler createMessageProcessingHandler(MessageProcessor<T> processor) {
-		return this.createMethodInvokingHandler(processor, "processMessage");
+		return this.createMethodInvokingHandler(processor, null);
 	}
 
 	MessageHandler createDefaultHandler() {

spring-integration-core/src/main/java/org/springframework/integration/filter/MethodInvokingSelector.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.
@@ -20,13 +20,15 @@ import java.lang.reflect.Method;
 
 import org.springframework.integration.annotation.Filter;
 import org.springframework.integration.core.MessageSelector;
+import org.springframework.integration.handler.MessageProcessor;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 import org.springframework.util.Assert;
 
 /**
  * A method-invoking implementation of {@link MessageSelector}.
- * 
+ *
  * @author Mark Fisher
+ * @author Artem Bilan
  */
 public class MethodInvokingSelector extends AbstractMessageProcessingSelector {
 
@@ -42,8 +44,10 @@ public class MethodInvokingSelector extends AbstractMessageProcessingSelector {
 		super(new MethodInvokingMessageProcessor<Boolean>(object, methodName));
 	}
 
+	@SuppressWarnings("unchecked")
 	public MethodInvokingSelector(Object object) {
-		super(new MethodInvokingMessageProcessor<Boolean>(object, Filter.class));
+		super(object instanceof MessageProcessor<?> ? (MessageProcessor<Boolean>) object :
+				new MethodInvokingMessageProcessor<Boolean>(object, Filter.class));
 	}
 
 }

spring-integration-core/src/main/java/org/springframework/integration/router/AbstractMessageProcessingRouter.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.
@@ -28,16 +28,16 @@ import org.springframework.util.Assert;
 /**
  * A base class for Router implementations that delegate to a
  * {@link MessageProcessor} instance.
- * 
+ *
  * @author Mark Fisher
  * @since 2.0
  */
 class AbstractMessageProcessingRouter extends AbstractMappingMessageRouter {
 
-	private final MessageProcessor<Object> messageProcessor;
+	private final MessageProcessor<?> messageProcessor;
 
 
-	AbstractMessageProcessingRouter(MessageProcessor<Object> messageProcessor) {
+	AbstractMessageProcessingRouter(MessageProcessor<?> messageProcessor) {
 		Assert.notNull(messageProcessor, "messageProcessor must not be null");
 		this.messageProcessor = messageProcessor;
 	}
@@ -47,7 +47,7 @@ class AbstractMessageProcessingRouter extends AbstractMappingMessageRouter {
 	public final void onInit() {
 		super.onInit();
 		if (this.messageProcessor instanceof AbstractMessageProcessor) {
-			((AbstractMessageProcessor<Object>) this.messageProcessor).setConversionService(this.getConversionService());
+			((AbstractMessageProcessor<?>) this.messageProcessor).setConversionService(this.getConversionService());
 		}
 		if (this.messageProcessor instanceof BeanFactoryAware) {
 			((BeanFactoryAware) this.messageProcessor).setBeanFactory(this.getBeanFactory());

spring-integration-core/src/main/java/org/springframework/integration/router/MethodInvokingRouter.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.
@@ -19,6 +19,7 @@ package org.springframework.integration.router;
 import java.lang.reflect.Method;
 
 import org.springframework.integration.annotation.Router;
+import org.springframework.integration.handler.MessageProcessor;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 import org.springframework.integration.support.channel.ChannelResolver;
 
@@ -28,8 +29,9 @@ import org.springframework.integration.support.channel.ChannelResolver;
  * String to be interpreted as a channel name, or a Collection (or Array) of
  * either type. If the method returns channel names, then a
  * {@link ChannelResolver} is required.
- * 
+ *
  * @author Mark Fisher
+ * @author Artem Bilan
  */
 public class MethodInvokingRouter extends AbstractMessageProcessingRouter {
 
@@ -42,7 +44,8 @@ public class MethodInvokingRouter extends AbstractMessageProcessingRouter {
 	}
 
 	public MethodInvokingRouter(Object object) {
-		super(new MethodInvokingMessageProcessor<Object>(object, Router.class));
+		super(object instanceof MessageProcessor<?> ? (MessageProcessor<?>) object :
+				new MethodInvokingMessageProcessor<Object>(object, Router.class));
 	}
 
 }

spring-integration-core/src/main/java/org/springframework/integration/splitter/MethodInvokingSplitter.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.
@@ -20,6 +20,7 @@ import java.lang.reflect.Method;
 import java.util.Collection;
 
 import org.springframework.integration.annotation.Splitter;
+import org.springframework.integration.handler.MessageProcessor;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 
 /**
@@ -28,8 +29,9 @@ import org.springframework.integration.handler.MethodInvokingMessageProcessor;
  * is a Collection or Array. If the return value is not a Collection or
  * Array, then the single Object will be returned as the payload of a
  * single reply Message.
- * 
+ *
  * @author Mark Fisher
+ * @author Artem Bilan
  */
 public class MethodInvokingSplitter extends AbstractMessageProcessingSplitter {
 
@@ -41,8 +43,10 @@ public class MethodInvokingSplitter extends AbstractMessageProcessingSplitter {
 		super(new MethodInvokingMessageProcessor<Collection<?>>(object, methodName));
 	}
 
+	@SuppressWarnings("unchecked")
 	public MethodInvokingSplitter(Object object) {
-		super(new MethodInvokingMessageProcessor<Collection<?>>(object, Splitter.class));
+		super(object instanceof MessageProcessor<?> ? (MessageProcessor<Collection<?>>) object :
+				new MethodInvokingMessageProcessor<Collection<?>>(object, Splitter.class));
 	}
 
 }

spring-integration-core/src/main/java/org/springframework/integration/transformer/MethodInvokingTransformer.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.
@@ -19,6 +19,7 @@ package org.springframework.integration.transformer;
 import java.lang.reflect.Method;
 
 import org.springframework.integration.annotation.Transformer;
+import org.springframework.integration.handler.MessageProcessor;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 
 /**
@@ -26,8 +27,9 @@ import org.springframework.integration.handler.MethodInvokingMessageProcessor;
  * on the given object. The method's return value will be considered as
  * the payload of a new Message unless the return value is itself already
  * a Message.
- * 
+ *
  * @author Mark Fisher
+ * @author Artem Bilan
  */
 public class MethodInvokingTransformer extends AbstractMessageProcessingTransformer {
 
@@ -40,7 +42,8 @@ public class MethodInvokingTransformer extends AbstractMessageProcessingTransfor
 	}
 
 	public MethodInvokingTransformer(Object object) {
-		super(new MethodInvokingMessageProcessor<Object>(object, Transformer.class));
+		super(object instanceof MessageProcessor<?> ? (MessageProcessor<?>) object :
+				new MethodInvokingMessageProcessor<Object>(object, Transformer.class));
 	}
 
 }