线程池的实现Demo

1、缓存线程池

创建一个缓存线程池，此方法不会对线程数量进行限制，jvm能创建多少就是用多少。线程可复用。

public static void main (String args[]) throws InterruptedException {
        ExecutorService executorService = Executors.newCachedThreadPool();
        for(int i = 0 ; i < 10 ; i ++){
            final int num = i;
            Thread.sleep(i*1000);
            executorService.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(num);
                }
            });
        }
    }

 

2、定长线程池

创建一个固定数量的线程池。

 public static void main (String args[]) throws InterruptedException {
        ExecutorService executorService = Executors.newFixedThreadPool(2);

        for(int i = 0 ; i < 10 ; i ++){
            final int num = i ;
            executorService.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(num);
                    try {
                        Thread.sleep(2000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
        executorService.shutdown();
    }

 

3、定长循环执行的线程

    public static void main (String args[]){
        ScheduledExecutorService scheduledExecutorService = Executors.newScheduledThreadPool(5);
        scheduledExecutorService.scheduleAtFixedRate(new Runnable() {
            @Override
            public void run() {
                System.out.println("延迟1秒后每2秒执行一次");
            }
        },1,2, TimeUnit.SECONDS);
    }

4、单线程线程池

    public static void main (String args[]){
        ExecutorService executorService = Executors.newSingleThreadExecutor();
        for(int i = 0 ; i < 10 ; i ++){
            final int num = i;

            executorService.execute(new Runnable() {
                @Override
                public void run() {
                    System.out.println(num);
                    try {
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                }
            });
        }
    }