ThreadPoolExecutor和ThreadPoolTaskExecutor

在日常开发中，我们更常用的是ThreadPoolTaskExecutor。它和八股文中5种线程池有什么不一样呢？

ThreadPoolTaskExecutor是spring core包中的，而ThreadPoolExecutor是JDK中的JUC。ThreadPoolTaskExecutor是对ThreadPoolExecutor进行了封装处理。

ThreadPoolExecutor结构:

ThreadPoolTaskExecutor结构:

public class ThreadPoolTaskExecutor extends ExecutorConfigurationSupport
        implements AsyncListenableTaskExecutor, SchedulingTaskExecutor {
    @Override
    protected ExecutorService initializeExecutor(
            ThreadFactory threadFactory, RejectedExecutionHandler rejectedExecutionHandler) {

        BlockingQueue<Runnable> queue = createQueue(this.queueCapacity);

        ThreadPoolExecutor executor;
        if (this.taskDecorator != null) {
            executor = new ThreadPoolExecutor(
                    this.corePoolSize, this.maxPoolSize, this.keepAliveSeconds, TimeUnit.SECONDS,
                    queue, threadFactory, rejectedExecutionHandler) {
                @Override
                public void execute(Runnable command) {
                    Runnable decorated = taskDecorator.decorate(command);
                    if (decorated != command) {
                        decoratedTaskMap.put(decorated, command);
                    }
                    super.execute(decorated);
                }
            };
        } else {
            executor = new ThreadPoolExecutor(
                    this.corePoolSize, this.maxPoolSize, this.keepAliveSeconds, TimeUnit.SECONDS,
                    queue, threadFactory, rejectedExecutionHandler);
        }

        if (this.allowCoreThreadTimeOut) {
            executor.allowCoreThreadTimeOut(true);
        }
        if (this.prestartAllCoreThreads) {
            executor.prestartAllCoreThreads();
        }

        this.threadPoolExecutor = executor;
        return executor;
    }
}

从源码可以看到，ThreadPoolTaskExecutor是对ThreadPoolExecutor进行了封装。封装让我们摆脱了只能使用那5种无法自定义更多参数的线程池以及自己手动使用ThreadPoolExecutor带来的一些风险和繁琐的操作。