Executors类里边常用的四种线程池
public class Executors {
//1.newFixedThreadPool
创建一个定长线程池,可控制线程最大并发数,超出的线程会在无界队列中等待
public static ExecutorService newFixedThreadPool(int nThreads) {
return new ThreadPoolExecutor(nThreads, nThreads,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>());
}
//2.newSinglethreadExecutor
创建一个单线程化的线程池,它只会用唯一的工作线程来执行任务,保证所有的任务按照指定的顺序(FIFO,LIFO,优先级)执行
public static ExecutorService newSingleThreadExecutor() {
return new FinalizableDelegatedExecutorService
(new ThreadPoolExecutor(1, 1,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>()));
}
//3.newCachedThreadPool
创建一个可缓存线程池,如果线程池超过处理需要,可灵活回收空闲线程,若无回收线程,则新建线程
public static ExecutorService newCachedThreadPool() {
return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
60L, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>());
}
public static ExecutorService newCachedThreadPool(ThreadFactory threadFactory) {
return new ThreadPoolExecutor(0, Integer.MAX_VALUE,
60L, TimeUnit.SECONDS,
new SynchronousQueue<Runnable>(),
threadFactory);
}
//4.newScheduledThreadPool
创建一个定长线程池,支持定时及周期性任务执行
public static ScheduledExecutorService newScheduledThreadPool(int corePoolSize) {
return new ScheduledThreadPoolExecutor(corePoolSize);
}
}
//四种线程池其实内部方法都是调用的ThreadPoolExecutor类,只不过利用了其不同的构造方法而已(传入自己需要传入的参数),那么利用这个特性,我们自己也是可以实现自己定义的线程池
}