java核心知识点 --- 线程池ThreadPool

package com.amos.concurrent;import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;/**
* @ClassName: ThreadPoolTest
* @Description: java5中的线程池
* @author: amosli
* @email:hi_amos@outlook.com
* @date Apr 21, 2014 2:13:27 AM
*/
public class ThreadPoolTest { public static void main(String[] args) {
// ExecutorService executorService = Executors.newFixedThreadPool(3);//设置固定的线程数
// ExecutorService executorService = Executors.newCachedThreadPool();//创建带缓存的线程池,自动分配线程数
ExecutorService executorService = Executors.newSingleThreadExecutor();//创建单一线程池,如何实现线程死了,马上自动重新建一个
Executors.newScheduledThreadPool(3).schedule(new Runnable() {//创建一个有3个线程数的线程池,批定3秒后执行run方法里的内容
public void run() {
System.out.println("bomb.....");
}
}, 3, TimeUnit.SECONDS );//隔3秒 for (int i = 0; i < 10; i++) {//创建10个任务
final int task = i;
executorService.execute(new Runnable() {//执行任务的线程
public void run() {
for (int i = 0; i < 10; i++) {//循环执行10个次
System.out.println(Thread.currentThread().getName() + " loop" + i + " task is" + task);
}
}
});
}
System.out.println("all of 10 task has committed!!");
List<Runnable> shutdownNow = executorService.shutdownNow();//立即关闭线程,并返回未执行的线程
System.out.println("closed thread size:"+shutdownNow.size());
for(Runnable a:shutdownNow){
System.out.println(a);
}
}
}

package com.amos.concurrent;import static java.util.concurrent.TimeUnit.SECONDS;import java.util.Date;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;class BeeperControl {
private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1); public void beepForAnHour() {
final Runnable beeper = new Runnable() {
public void run() {
System.out.println(new Date().getSeconds());//计时
System.out.println("beep");
}
};
final ScheduledFuture beeperHandle = scheduler.scheduleAtFixedRate(beeper, 10, 2, SECONDS);//任务,10s delay,2s/次,单位秒 scheduler.schedule(new Runnable() {
public void run() {
beeperHandle.cancel(true);//撤消任务
}
}, 60 * 60, SECONDS);//60*60s=60min=1h
}
}
public class test{
public static void main(String[] args) {
System.out.println(new Date().getSeconds());//计时
new BeeperControl().beepForAnHour();
}
}