org.springframework.context.event.SimpleApplicationEventMulticaster Maven / Gradle / Ivy
/*
* Copyright 2002-2006 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.context.event;
import java.util.Iterator;
import org.springframework.context.ApplicationEvent;
import org.springframework.context.ApplicationListener;
import org.springframework.core.task.SyncTaskExecutor;
import org.springframework.core.task.TaskExecutor;
/**
* Simple implementation of the ApplicationEventMulticaster interface.
*
* Multicasts all events to all registered listeners, leaving it up to
* the listeners to ignore events that they are not interested in.
* Listeners will usually perform corresponding instanceof
* checks on the passed-in event object.
*
*
By default, all listeners are invoked in the calling thread.
* This allows the danger of a rogue listener blocking the entire application,
* but adds minimal overhead. Specify an alternative TaskExecutor to have
* listeners executed in different threads, for example from a thread pool.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see #setTaskExecutor
*/
public class SimpleApplicationEventMulticaster extends AbstractApplicationEventMulticaster {
private TaskExecutor taskExecutor = new SyncTaskExecutor();
/**
* Set the TaskExecutor to execute application listeners with.
*
Default is a SyncTaskExecutor, executing the listeners synchronously
* in the calling thread.
*
Consider specifying an asynchronous TaskExecutor here to not block the
* caller until all listeners have been executed. However, note that asynchronous
* execution will not participate in the caller's thread context (class loader,
* transaction association) unless the TaskExecutor explicitly supports this.
* @see org.springframework.core.task.SyncTaskExecutor
* @see org.springframework.core.task.SimpleAsyncTaskExecutor
* @see org.springframework.scheduling.timer.TimerTaskExecutor
*/
public void setTaskExecutor(TaskExecutor taskExecutor) {
this.taskExecutor = (taskExecutor != null ? taskExecutor : new SyncTaskExecutor());
}
/**
* Return the current TaskExecutor for this multicaster.
*/
protected TaskExecutor getTaskExecutor() {
return taskExecutor;
}
public void multicastEvent(final ApplicationEvent event) {
for (Iterator it = getApplicationListeners().iterator(); it.hasNext();) {
final ApplicationListener listener = (ApplicationListener) it.next();
getTaskExecutor().execute(new Runnable() {
public void run() {
listener.onApplicationEvent(event);
}
});
}
}
}