spring 线程池疑问？

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spring 线程池疑问？5

哪位大神知道 spring封装的线程池源码里面

ExecutorConfigurationSupport
成员变量
private ExecutorService executor;

ThreadPoolTaskExecutor类继承ExecutorConfigurationSupport类

成员变量
private ThreadPoolExecutor threadPoolExecutor;
方法
protected ExecutorService initializeExecutor(
ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) {
BlockingQueue<Runnable> queue = createQueue(this.queueCapacity);
ThreadPoolExecutor executor = new ThreadPoolExecutor(this.corePoolSize, this.maxPoolSize, this.keepAliveSeconds, TimeUnit.SECONDS,queue, threadFactory, rejectedExecutionHandler);
if (this.allowCoreThreadTimeOut) {
executor.allowCoreThreadTimeOut(true);
}
this.threadPoolExecutor = executor;
return executor;
}

ThreadPoolTaskExecutor任务执行是采用的自身成员变量
private ThreadPoolExecutor threadPoolExecutor;

那么父类ExecutorConfigurationSupport的成员变量private ExecutorService executor;虽然初始化了，实际没有用到

请问这里面是什么原因？

ExecutorConfigurationSupport类初始化方法
public void initialize() {
if (logger.isInfoEnabled()) {
logger.info("Initializing ExecutorService " + (this.beanName != null ? " '" + this.beanName + "'" : ""));
}
if (!this.threadNamePrefixSet && this.beanName != null) {
setThreadNamePrefix(this.beanName + "-");
}
this.executor = initializeExecutor(this.threadFactory, this.rejectedExecutionHandler);
}
抽象方法由子类ThreadPoolTaskExecutor实现
protected abstract ExecutorService initializeExecutor(
ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler);

问题补充：ThreadPoolTaskExecutor类获取线程执行器
public ThreadPoolExecutor getThreadPoolExecutor() throws IllegalStateException {
Assert.state(this.threadPoolExecutor != null, "ThreadPoolTaskExecutor not initialized");
return this.threadPoolExecutor;
}

问题补充：可是ThreadPoolTaskExecutor类实际是调用的自身的成员变量

它并没有调用父类ExecutorConfigurationSupport的成员变量private ExecutorService executor;

下面是ThreadPoolTaskExecutor类的方法

public ThreadPoolExecutor getThreadPoolExecutor() throws IllegalStateException {
Assert.state(this.threadPoolExecutor != null, "ThreadPoolTaskExecutor not initialized");
return this.threadPoolExecutor;
}

执行任务也是用的这个成员变量this.threadPoolExecutor

public void execute(Runnable task) {
Executor executor = getThreadPoolExecutor();
try {
executor.execute(task);
}
catch (RejectedExecutionException ex) {
throw new TaskRejectedException("Executor [" + executor + "] did not accept task: " + task, ex);
}
}

那么这里我不解的是父类ExecutorConfigurationSupport的成员变量private ExecutorService executor;

虽然有它的初始化销毁方法可是实际上在执行任务的时候并没有用到？

ThreadPoolExecutor ThreadPoolTaskExecutor

2012年12月17日 11:34

chenying998179
2
0 0 5

1个答案按时间排序按投票排序

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采纳的答案

父类中的executor 是用到的：

	public void shutdown() {
		if (logger.isInfoEnabled()) {
			logger.info("Shutting down ExecutorService" + (this.beanName != null ? " '" + this.beanName + "'" : ""));
		}
		if (this.waitForTasksToCompleteOnShutdown) {
			this.executor.shutdown();
		}
		else {
			this.executor.shutdownNow();
		}
	}

用于停止executor时使用

ThreadPoolExecutor是池化的Executor实现，我们可以实现其他的；

就像struts2的Action 与 ActionSupport一样，ActionSupport提供了如验证、国际化的功能，我们可以复用它，但不一定使用它

2012年12月17日 13:20