/*
* Copyright 2006-2007 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.batch.core.configuration.support;
import java.util.ArrayList;
import java.util.Collection;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.configuration.DuplicateJobException;
import org.springframework.batch.core.configuration.JobRegistry;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ApplicationListener;
import org.springframework.context.Lifecycle;
import org.springframework.context.event.ApplicationContextEvent;
import org.springframework.context.event.ContextClosedEvent;
import org.springframework.context.event.ContextRefreshedEvent;
import org.springframework.core.Ordered;
import org.springframework.util.Assert;
/**
* Loads and unloads {@link Job Jobs} when the application context is created and destroyed. Each resource provided is
* loaded as an application context with the current context as its parent, and then all the jobs from the child context
* are registered under their bean names. A {@link JobRegistry} is required.
*
* @author Lucas Ward
* @author Dave Syer
*
* @since 2.1
*/
public class AutomaticJobRegistrar implements Ordered, Lifecycle, ApplicationListener<ApplicationContextEvent>, ApplicationContextAware,
InitializingBean {
private Collection<ApplicationContextFactory> applicationContextFactories = new ArrayList<ApplicationContextFactory>();
private JobLoader jobLoader;
private ApplicationContext applicationContext;
private volatile boolean running = false;
private Object lifecycleMonitor = new Object();
private int order = Ordered.LOWEST_PRECEDENCE;
/**
* The enclosing application context, which can be used to check if {@link ApplicationContextEvent events} come
* from the expected source.
*
* @param applicationContext the enclosing application context if there is one
* @see ApplicationContextAware#setApplicationContext(ApplicationContext)
*/
@Override
public void setApplicationContext(ApplicationContext applicationContext) {
this.applicationContext = applicationContext;
}
/**
* Add some factories to the set that will be used to load contexts and jobs.
*
* @param applicationContextFactory the {@link ApplicationContextFactory} values to use
*/
public void addApplicationContextFactory(ApplicationContextFactory applicationContextFactory) {
if (applicationContextFactory instanceof ApplicationContextAware) {
((ApplicationContextAware) applicationContextFactory).setApplicationContext(applicationContext);
}
this.applicationContextFactories.add(applicationContextFactory);
}
/**
* Add some factories to the set that will be used to load contexts and jobs.
*
* @param applicationContextFactories the {@link ApplicationContextFactory} values to use
*/
public void setApplicationContextFactories(ApplicationContextFactory[] applicationContextFactories) {
for (ApplicationContextFactory applicationContextFactory : applicationContextFactories) {
this.applicationContextFactories.add(applicationContextFactory);
}
}
/**
* The job loader that will be used to load and manage jobs.
*
* @param jobLoader the {@link JobLoader} to set
*/
public void setJobLoader(JobLoader jobLoader) {
this.jobLoader = jobLoader;
}
@Override
public int getOrder() {
return order;
}
/**
* The order to start up and shutdown.
* @param order the order (default {@link Ordered#LOWEST_PRECEDENCE}).
* @see Ordered
*/
public void setOrder(int order) {
this.order = order;
}
/**
*/
@Override
public void afterPropertiesSet() {
Assert.state(jobLoader != null, "A JobLoader must be provided");
}
/**
* Creates all the application contexts required and set up job registry entries with all the instances of
* {@link Job} found therein. Also closes the contexts when the enclosing context is closed.
*
* @see InitializingBean#afterPropertiesSet()
*/
@Override
public final void onApplicationEvent(ApplicationContextEvent event) {
// TODO: With Spring 3 a SmartLifecycle is started automatically
if (event.getSource() == applicationContext) {
if (event instanceof ContextRefreshedEvent) {
start();
}
else if (event instanceof ContextClosedEvent) {
stop();
}
}
}
/**
* Delegates to {@link JobLoader#clear()}.
*
* @see Lifecycle#stop()
*/
@Override
public void stop() {
synchronized (this.lifecycleMonitor) {
jobLoader.clear();
running = false;
}
}
/**
* Take all the contexts from the factories provided and pass them to the {@link JobLoader}.
*
* @see Lifecycle#start()
*/
@Override
public void start() {
synchronized (this.lifecycleMonitor) {
if (running) {
return;
}
for (ApplicationContextFactory factory : applicationContextFactories) {
try {
jobLoader.load(factory);
}
catch (DuplicateJobException e) {
throw new IllegalStateException(e);
}
}
running = true;
}
}
/**
* Check if this component has been started.
*
* @return true if started successfully and not stopped
* @see Lifecycle#isRunning()
*/
@Override
public boolean isRunning() {
synchronized (this.lifecycleMonitor) {
return running;
}
}
}