Removed Splitter interface and added AbstractMessageSplitter base class. The MethodInvokingSplitter is now capable of resolving methods when only an Object is provided to its constructor - either a single method containing the @Splitter annotation or a single public Method as a fallback (or if neither is satisifed, an IllegalArgumentException will be thrown).

org.springframework.integration/src/main/java/org/springframework/integration/config/SplitterParser.java

@@ -20,8 +20,9 @@ import org.w3c.dom.Element;
 
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.xml.ParserContext;
+import org.springframework.integration.splitter.DefaultMessageSplitter;
 import org.springframework.integration.splitter.MethodInvokingSplitter;
-import org.springframework.integration.splitter.SplitterEndpoint;
+import org.springframework.util.StringUtils;
 
 /**
  * Parser for the <splitter/> element.
@@ -32,12 +33,17 @@ public class SplitterParser extends AbstractEndpointParser {
 
 	@Override
 	protected BeanDefinitionBuilder parseConsumer(Element element, ParserContext parserContext) {
-		BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(SplitterEndpoint.class);
-		if (element.hasAttribute("ref")) {
-			String adapterBeanName = this.parseAdapter(element, parserContext, MethodInvokingSplitter.class);
-			builder.addConstructorArgReference(adapterBeanName);
+		if (element.hasAttribute(REF_ATTRIBUTE)) {
+			String ref = element.getAttribute(REF_ATTRIBUTE);
+			BeanDefinitionBuilder builder = BeanDefinitionBuilder.genericBeanDefinition(MethodInvokingSplitter.class);
+			builder.addConstructorArgReference(ref);
+			if (StringUtils.hasText(element.getAttribute(METHOD_ATTRIBUTE))) {
+				String method = element.getAttribute(METHOD_ATTRIBUTE);
+				builder.addConstructorArgValue(method);
+			}
+			return builder;
 		}
-		return builder;
+		return BeanDefinitionBuilder.genericBeanDefinition(DefaultMessageSplitter.class);
 	}
 
 }

org.springframework.integration/src/main/java/org/springframework/integration/config/annotation/SplitterAnnotationPostProcessor.java

@@ -22,7 +22,6 @@ import org.springframework.integration.annotation.Splitter;
 import org.springframework.integration.bus.MessageBus;
 import org.springframework.integration.message.MessageConsumer;
 import org.springframework.integration.splitter.MethodInvokingSplitter;
-import org.springframework.integration.splitter.SplitterEndpoint;
 
 /**
  * Post-processor for Methods annotated with {@link Splitter @Splitter}.
@@ -38,8 +37,7 @@ public class SplitterAnnotationPostProcessor extends AbstractMethodAnnotationPos
 
 	@Override
 	protected MessageConsumer createConsumer(Object bean, Method method, Splitter annotation) {
-		MethodInvokingSplitter splitter = new MethodInvokingSplitter(bean, method);
-		return new SplitterEndpoint(splitter);
+		return new MethodInvokingSplitter(bean, method);
 	}
 
 }

org.springframework.integration/src/main/java/org/springframework/integration/message/CompositeMessage.java

@@ -21,7 +21,6 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
-
 /**
  * @author Mark Fisher
  */

org.springframework.integration/src/main/java/org/springframework/integration/splitter/AbstractMessageSplitter.java

@@ -20,17 +20,30 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
 
+import org.springframework.integration.endpoint.AbstractReplyProducingMessageConsumer;
+import org.springframework.integration.message.CompositeMessage;
 import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageBuilder;
 import org.springframework.integration.message.MessageHeaders;
 
 /**
+ * Base class for Message-splitting consumers.
+ * 
  * @author Mark Fisher
  */
-public abstract class AbstractSplitter implements Splitter {
+public abstract class AbstractMessageSplitter extends AbstractReplyProducingMessageConsumer {
 
-	public List<Message<?>> split(Message<?> message) {
+	@Override
+	protected final boolean shouldSplitComposite() {
+		return true;
+	}
+
+	@Override
+	protected final Message<?> handle(Message<?> message) {
 		Object result = this.splitMessage(message);
+		if (result == null) {
+			return null;
+		}
 		MessageHeaders requestHeaders = message.getHeaders();
 		List<Message<?>> results = new ArrayList<Message<?>>();
 		if (result instanceof Collection) {
@@ -55,11 +68,20 @@ public abstract class AbstractSplitter implements Splitter {
 		if (results.isEmpty()) {
 			return null;
 		}
-		return results;
+		return new CompositeMessage(results);
 	}
 
+	/**
+	 * Subclasses must override this method to split the received Message. The
+	 * return value may be a Collection or Array. The individual elements may
+	 * be Messages, but it is not necessary. If the elements are not Messages,
+	 * each will be provided as the payload of a Message. It is also acceptable
+	 * to return a single Object or Message. In that case, a single reply
+	 * Message will be produced.
+	 */
 	protected abstract Object splitMessage(Message<?> message);
 
+
 	private Message<?> createSplitMessage(Object item, MessageHeaders requestHeaders, int sequenceNumber, int sequenceSize) {
 		if (item instanceof Message<?>) {
 			return setSplitMessageHeaders(MessageBuilder.fromMessage((Message<?>) item),

org.springframework.integration/src/main/java/org/springframework/integration/splitter/DefaultMessageSplitter.java

@@ -23,9 +23,14 @@ import java.util.StringTokenizer;
 import org.springframework.integration.message.Message;
 
 /**
+ * The default Message Splitter implementation. Returns individual Messages
+ * after receiving an array or Collection. If a value is provided for the
+ * 'delimiters' property, then String payloads will be tokenized based on
+ * those delimiters.
+ * 
  * @author Mark Fisher
  */
-public class DefaultSplitter extends AbstractSplitter {
+public class DefaultMessageSplitter extends AbstractMessageSplitter {
 
 	private volatile String delimiters;
 
@@ -39,7 +44,7 @@ public class DefaultSplitter extends AbstractSplitter {
 		this.delimiters = delimiters;
 	}
 
-	public Object splitMessage(Message<?> message) {
+	protected final Object splitMessage(Message<?> message) {
 		Object payload = message.getPayload();
 		if (payload instanceof String && this.delimiters != null) {
 			List<String> tokens = new ArrayList<String>();

org.springframework.integration/src/main/java/org/springframework/integration/splitter/MethodInvokingSplitter.java

@@ -19,11 +19,15 @@ package org.springframework.integration.splitter;
 import java.lang.reflect.Method;
 
 import org.springframework.beans.factory.InitializingBean;
+import org.springframework.integration.annotation.Splitter;
 import org.springframework.integration.message.Message;
 import org.springframework.integration.message.MessageMappingMethodInvoker;
+import org.springframework.integration.util.DefaultMethodResolver;
+import org.springframework.integration.util.MethodResolver;
+import org.springframework.util.Assert;
 
 /**
- * A {@link Splitter} implementation that invokes the specified method
+ * A Message Splitter implementation that invokes the specified method
  * on the given object. The method's return value will be split if it
  * 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
@@ -31,7 +35,9 @@ import org.springframework.integration.message.MessageMappingMethodInvoker;
  * 
  * @author Mark Fisher
  */
-public class MethodInvokingSplitter extends AbstractSplitter implements Splitter, InitializingBean {
+public class MethodInvokingSplitter extends AbstractMessageSplitter implements InitializingBean {
+
+	private final MethodResolver methodResolver = new DefaultMethodResolver(Splitter.class);
 
 	private final MessageMappingMethodInvoker invoker;
 
@@ -44,6 +50,14 @@ public class MethodInvokingSplitter extends AbstractSplitter implements Splitter
 		this.invoker = new MessageMappingMethodInvoker(object, methodName);
 	}
 
+	public MethodInvokingSplitter(Object object) {
+		Assert.notNull(object, "object must not be null");
+		Method method = this.methodResolver.findMethod(object.getClass()); 
+		Assert.notNull(method, "unable to resolve Splitter method on target class ["
+				+ object.getClass() + "]");
+		this.invoker = new MessageMappingMethodInvoker(object, method);
+	}
+
 
 	public void afterPropertiesSet() throws Exception {
 		this.invoker.afterPropertiesSet();

org.springframework.integration/src/main/java/org/springframework/integration/splitter/Splitter.java

@@ -1,33 +0,0 @@
-/*
- * Copyright 2002-2008 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.splitter;
-
-import java.util.List;
-
-import org.springframework.integration.message.Message;
-
-/**
- * Strategy interface for splitting a single {@link Message}
- * into multiple Messages.
- * 
- * @author Mark Fisher
- */
-public interface Splitter {
-
-	List<Message<?>> split(Message<?> message);
-
-}

org.springframework.integration/src/main/java/org/springframework/integration/splitter/SplitterEndpoint.java

@@ -1,58 +0,0 @@
-/*
- * Copyright 2002-2008 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.splitter;
-
-import java.util.List;
-
-import org.springframework.integration.endpoint.AbstractReplyProducingMessageConsumer;
-import org.springframework.integration.message.CompositeMessage;
-import org.springframework.integration.message.Message;
-import org.springframework.util.Assert;
-
-/**
- * @author Mark Fisher
- */
-public class SplitterEndpoint extends AbstractReplyProducingMessageConsumer {
-
-	private final Splitter splitter;
-
-
-	public SplitterEndpoint() {
-		this(new DefaultSplitter());
-	}
-
-	public SplitterEndpoint(Splitter splitter) {
-		Assert.notNull(splitter, "splitter must not be null");
-		this.splitter = splitter;
-	}
-
-
-	@Override
-	protected boolean shouldSplitComposite() {
-		return true;
-	}
-
-	@Override
-	protected Message<?> handle(Message<?> message) {
-		List<Message<?>> results = this.splitter.split(message);
-		if (results == null || results.isEmpty()) {
-			return null;
-		}
-		return new CompositeMessage(results);
-	}
-
-}