/*
* 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.synapse.MessageContext;
import org.apache.synapse.Mediator;
import org.apache.synapse.ManagedLifecycle;
import org.apache.synapse.SynapseException;
import org.apache.synapse.SynapseLog;
import org.apache.synapse.core.SynapseEnvironment;
import org.apache.synapse.mediators.AbstractMediator;
import org.apache.synapse.config.SynapseConfigUtils;
import org.apache.synapse.config.Entry;
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 in-lined Spring configuration.
*/
@SuppressWarnings({"UnusedDeclaration"})
public class SpringMediator extends AbstractMediator implements ManagedLifecycle {
/**
* 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) {
SynapseLog synLog = getLog(synCtx);
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Start : Spring mediator");
if (synLog.isTraceTraceEnabled()) {
synLog.traceTrace("Message : " + synCtx.getEnvelope());
}
}
Entry entry = synCtx.getConfiguration().getEntryDefinition(configKey);
// if the configKey refers to a dynamic property
if (entry != null && entry.isDynamic()) {
if (!entry.isCached() || entry.isExpired()) {
buildAppContext(synCtx, synLog);
}
// if the property is not a DynamicProperty, we will create an ApplicationContext only once
} else {
if (appContext == null) {
buildAppContext(synCtx, synLog);
}
}
if (appContext != null) {
Object o = appContext.getBean(beanName);
if (o != null && Mediator.class.isAssignableFrom(o.getClass())) {
Mediator m = (Mediator) o;
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Loaded mediator from bean : " + beanName + " executing...");
}
return m.mediate(synCtx);
} else {
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Unable to load mediator from bean : " + beanName);
}
handleException("Could not load bean named : " + beanName +
" from the Spring configuration with key : " + configKey, synCtx);
}
} else {
handleException("Cannot reference application context with key : " + configKey, synCtx);
}
synLog.traceOrDebug("End : Spring mediator");
return true;
}
private synchronized void buildAppContext(MessageContext synCtx,
SynapseLog synLog) {
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Creating Spring ApplicationContext from key : " + configKey);
}
GenericApplicationContext appContext = new GenericApplicationContext();
XmlBeanDefinitionReader xbdr = new XmlBeanDefinitionReader(appContext);
xbdr.setValidating(false);
Object springConfig = synCtx.getEntry(configKey);
if(springConfig == null) {
String errorMessage = "Cannot look up Spring configuration " + configKey;
log.error(errorMessage);
throw new SynapseException(errorMessage);
}
xbdr.loadBeanDefinitions(
new InputStreamResource(
SynapseConfigUtils.getStreamSource(springConfig).getInputStream()));
appContext.refresh();
if (synLog.isTraceOrDebugEnabled()) {
synLog.traceOrDebug("Spring ApplicationContext from key : " + configKey + " created");
}
this.appContext = appContext;
}
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 void init(SynapseEnvironment se) {
MessageContext synCtx = se.createMessageContext();
buildAppContext(synCtx, getLog(synCtx));
}
public void destroy() {
}
}