线程池Executors

3个线程的线程池提交10个任务

import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;


public class ThreadPoolTest {
    
public static void main(String[] args) {
  ExecutorService threadPool =Executors.newFixedThreadPool(3);
 //ExecutorService threadPool =Executors.newCachedThreadPool();//池子里面的线程数动态变化
    //ExecutorService threadPool =Executors.newSingleThreadExecutor();//单个线程池，线程死了会找个替补，保证线程不会挂掉
 for(int i=1;i<=10;i++){
    final int k=i;
 threadPool.execute(new Runnable() {
    
    @Override
    public void run() {
        for (int j=1;j<=10;j++){
            try {
                Thread.sleep(20);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println(Thread.currentThread().getName()+" looping of "+j+" for task of "+k);
        }
        
    }
});
 }
 System.out.println("All of 1o tasks have committed");
 threadPool.shutdown();//线程池必须关闭线程才能停止，任务干完了关闭
 //threadPool.shutdownNow();//任务没干完也立即关闭
 
 //定时器，调度线程池,10s后执行
 Executors.newScheduledThreadPool(3).schedule(new Runnable() {
    
    @Override
    public void run() {
        
    System.out.println("bombing!");
    
    }
}, 10, TimeUnit.SECONDS);
 //4s后开炸,然后每隔2s开炸
 Executors.newScheduledThreadPool(3).scheduleAtFixedRate(new Runnable() {
        
    @Override
    public void run() {
        
    System.out.println("bombing!");
    
    }
}, 4,2, TimeUnit.SECONDS);
 
//变相绝对定时，无绝对时间定时
 
 System.err.println(new Date().getTime()-System.currentTimeMillis());
}

}