INT-1060 Added @Filter annotation.

org.springframework.integration/src/main/java/org/springframework/integration/annotation/Filter.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2002-2010 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.annotation;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a method is capable of playing the role of a Message Filter.
+ * <p>
+ * A method annotated with @Filter may accept a parameter of type
+ * {@link org.springframework.integration.core.Message} or of the expected
+ * Message payload's type. Any type conversion supported by default or any
+ * Converters registered with the "integrationConversionService" bean will be
+ * applied to the Message payload if necessary. Header values can also be passed
+ * as Message parameters by using the {@link Header @Header} parameter annotation.
+ * <p>
+ * The return type of the annotated method must be a boolean (or Boolean).
+ * 
+ * @author Mark Fisher
+ * @since 2.0
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface Filter {
+
+	String inputChannel() default "";
+
+	String outputChannel() default "";
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -53,15 +53,17 @@ public class FilterFactoryBean extends AbstractMessageHandlerFactoryBean {
 
 	@Override
 	MessageHandler createMethodInvokingHandler(Object targetObject, String targetMethodName) {
+		MessageSelector selector = null;
 		if (targetObject instanceof MessageSelector) {
-			return this.createFilter((MessageSelector) targetObject);
+			selector = (MessageSelector) targetObject;
 		}
-		if (StringUtils.hasText(targetMethodName)) {
-			MessageSelector selector = new MethodInvokingSelector(targetObject, targetMethodName);
-			return this.createFilter(selector);
+		else if (StringUtils.hasText(targetMethodName)) {
+			selector = new MethodInvokingSelector(targetObject, targetMethodName);
 		}
-		throw new IllegalArgumentException("Filter must provide a target method" +
-				" name if the 'ref' does not point to a MessageSelector instance.");
+		else {
+			selector = new MethodInvokingSelector(targetObject);
+		}
+		return this.createFilter(selector);
 	}
 
 	@Override

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

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2002-2010 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.config.annotation;
+
+import java.lang.reflect.Method;
+
+import org.springframework.beans.factory.ListableBeanFactory;
+import org.springframework.integration.annotation.Filter;
+import org.springframework.integration.filter.MessageFilter;
+import org.springframework.integration.filter.MethodInvokingSelector;
+import org.springframework.integration.message.MessageHandler;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
+
+/**
+ * Post-processor for Methods annotated with {@link Filter @Filter}.
+ *
+ * @author Mark Fisher
+ * @since 2.0
+ */
+public class FilterAnnotationPostProcessor extends AbstractMethodAnnotationPostProcessor<Filter> {
+
+	public FilterAnnotationPostProcessor(ListableBeanFactory beanFactory) {
+		super(beanFactory);
+	}
+
+
+	@Override
+	protected MessageHandler createHandler(Object bean, Method method, Filter annotation) {
+		Assert.isTrue(boolean.class.equals(method.getReturnType()) || Boolean.class.equals(method.getReturnType()),
+				"The Filter annotation may only be applied to methods with a boolean return type.");
+		MethodInvokingSelector selector = new MethodInvokingSelector(bean, method);
+		MessageFilter filter = new MessageFilter(selector);
+		String outputChannelName = annotation.outputChannel();
+		if (StringUtils.hasText(outputChannelName)) {
+			filter.setOutputChannel(this.channelResolver.resolveChannelName(outputChannelName));
+		}
+		return filter;
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -44,6 +44,7 @@ import org.springframework.context.Lifecycle;
 import org.springframework.context.SmartLifecycle;
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.integration.annotation.Aggregator;
+import org.springframework.integration.annotation.Filter;
 import org.springframework.integration.annotation.Router;
 import org.springframework.integration.annotation.ServiceActivator;
 import org.springframework.integration.annotation.Splitter;
@@ -57,7 +58,7 @@ import org.springframework.util.StringUtils;
 
 /**
  * A {@link BeanPostProcessor} implementation that processes method-level
- * messaging annotations such as @Transformer, @Splitter, and @Router.
+ * messaging annotations such as @Transformer, @Splitter, @Router, and @Filter.
  * 
  * @author Mark Fisher
  * @author Marius Bogoevici
@@ -87,11 +88,12 @@ public class MessagingAnnotationPostProcessor implements BeanPostProcessor, Bean
 
 	public void afterPropertiesSet() {
 		Assert.notNull(this.beanFactory, "BeanFactory must not be null");
-		postProcessors.put(Aggregator.class, new AggregatorAnnotationPostProcessor(this.beanFactory));
+		postProcessors.put(Filter.class, new FilterAnnotationPostProcessor(this.beanFactory));
 		postProcessors.put(Router.class, new RouterAnnotationPostProcessor(this.beanFactory));
+		postProcessors.put(Transformer.class, new TransformerAnnotationPostProcessor(this.beanFactory));
 		postProcessors.put(ServiceActivator.class, new ServiceActivatorAnnotationPostProcessor(this.beanFactory));
 		postProcessors.put(Splitter.class, new SplitterAnnotationPostProcessor(this.beanFactory));
-		postProcessors.put(Transformer.class, new TransformerAnnotationPostProcessor(this.beanFactory));
+		postProcessors.put(Aggregator.class, new AggregatorAnnotationPostProcessor(this.beanFactory));
 	}
 
 	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {

org.springframework.integration/src/main/java/org/springframework/integration/filter/MethodInvokingSelector.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2010 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.
@@ -18,6 +18,7 @@ package org.springframework.integration.filter;
 
 import java.lang.reflect.Method;
 
+import org.springframework.integration.annotation.Filter;
 import org.springframework.integration.handler.MethodInvokingMessageProcessor;
 import org.springframework.integration.selector.MessageSelector;
 import org.springframework.util.Assert;
@@ -41,4 +42,8 @@ public class MethodInvokingSelector extends AbstractMessageProcessingSelector {
 		super(new MethodInvokingMessageProcessor(object, methodName));
 	}
 
+	public MethodInvokingSelector(Object object) {
+		super(new MethodInvokingMessageProcessor(object, Filter.class));
+	}
+
 }