/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.synapse.mediators.spring;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.synapse.MessageContext;
import org.apache.synapse.SynapseException;
import org.apache.synapse.Mediator;
import org.apache.synapse.Constants;
import org.apache.synapse.mediators.AbstractMediator;
import org.apache.synapse.config.Util;
import org.apache.synapse.config.Property;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.GenericApplicationContext;
import org.springframework.core.io.InputStreamResource;
/**
* This mediator allows Spring beans implementing the org.apache.synapse.Mediator
* interface to mediate messages passing through Synapse.
*
* A Spring mediator is instantiated by Spring (see www.springframework.org). The mediator
* refers to a Spring bean name, and also either a Spring configuration defined to Synapse
* or an inlined Spring configuration.
*/
public class SpringMediator extends AbstractMediator {
private static final Log log = LogFactory.getLog(SpringMediator.class);
private static final Log trace = LogFactory.getLog(Constants.TRACE_LOGGER);
/**
* The Spring bean ref to be used
*/
private String beanName = null;
/**
* The named Spring config to be used
*/
private String configKey = null;
/**
* The Spring ApplicationContext to be used
*/
private ApplicationContext appContext = null;
public boolean mediate(MessageContext synCtx) {
boolean shouldTrace = shouldTrace(synCtx.getTracingState());
if (shouldTrace) {
trace.trace("Start : Spring mediator");
}
Property dp = synCtx.getConfiguration().getPropertyObject(configKey);
// if the configKey refers to a dynamic property
if (dp != null && dp.isDynamic()) {
if (!dp.isCached() || dp.isExpired()) {
buildAppContext(synCtx);
}
// if the property is not a DynamicProperty, we will create an ApplicationContext only once
} else {
if (appContext == null) {
buildAppContext(synCtx);
}
}
if (appContext != null) {
Object o = appContext.getBean(beanName);
if (o != null && Mediator.class.isAssignableFrom(o.getClass())) {
Mediator m = (Mediator) o;
if (shouldTrace) {
trace.trace("Loaded mediator from bean : " + beanName + " executing...");
}
return m.mediate(synCtx);
} else {
if (shouldTrace) {
trace.trace("Unable to load mediator from bean : " + beanName);
}
handleException("Could not load bean named : " + beanName +
" from the Spring configuration with key : " + configKey);
}
} else {
handleException("Cannot reference Spring application context with key : " + configKey);
}
if (shouldTrace) {
trace.trace("End : Spring mediator");
}
return true;
}
private synchronized void buildAppContext(MessageContext synCtx) {
log.debug("Creating Spring ApplicationContext from property key : " + configKey);
GenericApplicationContext appContext = new GenericApplicationContext();
XmlBeanDefinitionReader xbdr = new XmlBeanDefinitionReader(appContext);
xbdr.setValidating(false);
xbdr.loadBeanDefinitions(new InputStreamResource(
Util.getStreamSource(
synCtx.getConfiguration().getProperty(configKey)).getInputStream()));
appContext.refresh();
this.appContext = appContext;
}
private void handleException(String msg) {
log.error(msg);
throw new SynapseException(msg);
}
public void setBeanName(String beanName) {
this.beanName = beanName;
}
public String getBeanName() {
return beanName;
}
public String getConfigKey() {
return configKey;
}
public void setConfigKey(String configKey) {
this.configKey = configKey;
}
public ApplicationContext getAppContext() {
return appContext;
}
public void setAppContext(ApplicationContext appContext) {
this.appContext = appContext;
}
public String getType() {
return "SpringMediator";
}
}