Java多线程之ThreadPoolExecutor

1.ExecutorService demo

 

package com.ccy.thread.demo;

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

/**
 * 
 * <p> 
 * Title: ThreadPoolTest.java 
 * Package com.ccy.thread.demo 
 * </p>
 * <p>
 * Description: 线程池简单demo
 * <p>
 * @author Tom.Cai
 * @created 2015-12-30 下午10:45:14 
 * @version V1.0 
 *
 */
public class ThreadPoolTest {
	public static void main(String[] args) {
		//创建一个可重用固定线程数的线程池，以共享的无界队列方式来运行这些线程。
		ExecutorService threadPool = Executors.newFixedThreadPool(3);
		for (int i = 0; i < 6; i++) {
            Runnable worker = new workThread(String.valueOf(i));
            threadPool.execute(worker);
          }
		//启动一次顺序关闭，执行以前提交的任务，但不接受新任务。
		threadPool.shutdown();
		//  如果关闭后所有任务都已完成，则返回 true。
        while (!threadPool.isTerminated()) {
        	
        }
        System.out.println("all threads Finished");
	}
}


class workThread implements Runnable{
	private String command;
	
	
	
	public workThread(String command){
		this.command = command;
	}
	
	@Override
	public void run() {
		System.out.println(Thread.currentThread().getName()+" Start time-"+command);
		try {
			Thread.sleep(5000);
		} catch (Exception e) {
			e.printStackTrace();
		}
        System.out.println(Thread.currentThread().getName()+" End !!!");
	}
	
}

2.ThreadPoolExecutor demo

package com.ccy.thread.demo;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.Executors;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
 * 
 * <p> 
 * Title: ThreadPoolExecutorTest.java 
 * Package com.ccy.thread.demo 
 * </p>
 * <p>
 * Description: 线程池监控demo
 * <p>
 * @author Tom.Cai
 * @created 2015-12-30 下午10:48:21 
 * @version V1.0 
 *
 */
public class ThreadPoolExecutorTest {
	public static void main(String[] args) throws Exception {
		RejectedExecutionHandlerImpl rejectionHandler = new RejectedExecutionHandlerImpl();
		ThreadFactory threadFactory = Executors.defaultThreadFactory();
		//在初始化 ThreadPoolExecutor 时，初始线程池大小设为2、最大值设为4、线程工作等待队列大小设为2。
		//所以，如果当前有4个任务正在运行而此时又有新任务提交，工作队列将只存储2个任务和其他任务将交由RejectedExecutionHandlerImpl 处理。
		ThreadPoolExecutor executorPool = new ThreadPoolExecutor(2, 4, 10, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(2), threadFactory, rejectionHandler);
		MonitorThread monitor = new MonitorThread(executorPool);
        Thread monitorThread = new Thread(monitor);
        monitorThread.start();
        for(int i=0; i<10; i++){
            executorPool.execute(new workerThread(String.valueOf(i)));
        }
        Thread.sleep(30000);
        executorPool.shutdown();
        Thread.sleep(5000);
        monitor.shutdown();
	}
}

class RejectedExecutionHandlerImpl implements RejectedExecutionHandler {

	@Override
	public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
			System.out.println(r.toString() + " is rejected");
	}

}

class MonitorThread implements Runnable{
	private ThreadPoolExecutor executor;
	private boolean runFlag = true;
	
	public MonitorThread(ThreadPoolExecutor executor){
		this.executor = executor;
	}
	
	public void shutdown(){
        this.runFlag = false;
    }
 
	@Override
	public void run() {
		 while(runFlag){
             System.out.println(
                 String.format("[monitor] [%d/%d] Active: %d, Completed: %d, Task: %d, isShutdown: %s, isTerminated: %s",
                	 // 返回池中的当前线程数。
                     this.executor.getPoolSize(),
                     // 返回核心线程数。
                     this.executor.getCorePoolSize(),
                     this.executor.getActiveCount(),
                     this.executor.getCompletedTaskCount(),
                     //返回曾计划执行的近似任务总数。
                     this.executor.getTaskCount(),
                     this.executor.isShutdown(),
                     this.executor.isTerminated()));
             try {
                 Thread.sleep(3000);
             } catch (InterruptedException e) {
                 e.printStackTrace();
             }
     }
	}
	
}

class workerThread implements Runnable{
	private String command;
	
	public workerThread(String command){
		this.command = command;
	}
	
	@Override
	public void run() {
		System.out.println(Thread.currentThread().getName()+" Start time-"+command);
		try {
			Thread.sleep(5000);
		} catch (Exception e) {
			e.printStackTrace();
		}
        System.out.println(Thread.currentThread().getName()+" End !!!");
	}
	
}

 

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