INT-814, INT-839 Added PublisherAnnotationBeanPostProcessor, added tests for documenting usage of @Publisher annotation and AOP-based MessagePublisherInterceptor

org.springframework.integration/src/main/java/org/springframework/integration/aop/PublisherAnnotationBeanPostProcessor.java

@@ -0,0 +1,108 @@
+/*
+ * 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.aop;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.Method;
+
+import org.springframework.aop.framework.ProxyFactory;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.core.annotation.AnnotationUtils;
+import org.springframework.integration.core.MessageChannel;
+
+/**
+ * Will post process beans that contain @{@link Publisher} annotation.
+ * 
+ * @author Oleg Zhurakousky
+ * @since 2.0
+ *
+ */
+public class PublisherAnnotationBeanPostProcessor implements BeanPostProcessor, BeanFactoryAware, InitializingBean {
+
+	private BeanFactory beanFactory;
+	private MessageChannel defaultChannel;
+	private PublisherAnnotationAdvisor advisor;
+	/**
+	 * 
+	 */
+	public PublisherAnnotationBeanPostProcessor(){}
+	/**
+	 * 
+	 * @param defaultChannel
+	 */
+	public PublisherAnnotationBeanPostProcessor(MessageChannel defaultChannel){
+		this.defaultChannel = defaultChannel;
+	}
+	/**
+	 * 
+	 */
+	public Object postProcessAfterInitialization(Object bean, String beanName)
+			throws BeansException {
+		if (this.containsPublisherAnnotations(bean)){
+			ProxyFactory pf = new ProxyFactory(bean);
+			pf.addAdvisor(advisor);
+			bean = pf.getProxy();
+		}
+		return bean;
+	}
+	/**
+	 * 
+	 */
+	public Object postProcessBeforeInitialization(Object bean, String beanName)
+			throws BeansException {
+		return bean;
+	}
+	/**
+	 * 
+	 * @return
+	 */
+	public BeanFactory getBeanFactory() {
+		return beanFactory;
+	}
+	/**
+	 * 
+	 */
+	public void setBeanFactory(BeanFactory beanFactory) {
+		this.beanFactory = beanFactory;
+	}
+	/**
+	 * 
+	 */
+	public void afterPropertiesSet(){
+		advisor = new PublisherAnnotationAdvisor();
+		advisor.setBeanFactory(beanFactory);
+		advisor.setDefaultChannel(defaultChannel);
+	}
+	/**
+	 * 
+	 * @param bean
+	 * @return
+	 */
+	private boolean containsPublisherAnnotations(Object bean){
+		Method[] methods = bean.getClass().getMethods();
+		for (Method method : methods) {
+			Annotation publisher = AnnotationUtils.findAnnotation(method, Publisher.class);
+			if (publisher != null){
+				return true;
+			}
+		}
+		return false;
+	}
+}