Java 自定义 线程池与任务队列

说明：

1）使用了队列的先进先出思想

2）在执行的时候添加线程

3）在ThreadQueue 里实现从队列里取出线程

/**
*
* @Project    JavaDemos
* @Package    com.java.thread
* @author     chenlin
* @version    1.0
* @Date       2011年6月12日
*/
public class WorkQueue {

private int threadCounts;// 线程池的大小
private ThreadQueue[] threads;// 用数组实现线程池
private LinkedList queue;// 任务队列

public WorkQueue(int threadCounts) {
this.threadCounts = threadCounts;
this.threads = new ThreadQueue[threadCounts];
this.queue = new LinkedList();
for (int i = 0; i < threadCounts; i++) {
threads[i] = new ThreadQueue();
threads[i].start();// 启动所有工作线程
}
}

public void execute(Runnable r) {
synchronized (queue) {
queue.addLast(r);
queue.notify();
}
}

private class ThreadQueue extends Thread {// 工作线程类
@Override
public void run() {
Runnable r;
while (true) {
synchronized (queue) {
//
while (queue.isEmpty()) {
try {
queue.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
r = (Runnable) queue.removeFirst();// 有任务时，取出任务
}
r.run();
}

}
}

/**
* 在静态方法里调用内部类必须是静态的
*/
static class Mytask implements Runnable {// 任务接口
public void run() {
String name = Thread.currentThread().getName();
try {
Thread.sleep(100);// 模拟任务执行的时间
} catch (InterruptedException e) {
}
System.out.println(name + " executed OK");
}
}

public static void main(String[] args) {
WorkQueue wq = new WorkQueue(10);// 10个工作线程
Mytask r[] = new Mytask[20];// 20个任务
for (int i = 0; i < 20; i++) {
r[i] = new Mytask();
wq.execute(r[i]);
}
}

}

运行结果：

Thread-2 executed OK

Thread-6 executed OK

Thread-1 executed OK

Thread-5 executed OK

Thread-9 executed OK

Thread-7 executed OK

Thread-4 executed OK

Thread-8 executed OK

Thread-3 executed OK

Thread-0 executed OK

Thread-2 executed OK

Thread-5 executed OK

Thread-1 executed OK

Thread-9 executed OK

Thread-7 executed OK

Thread-6 executed OK

Thread-4 executed OK

Thread-8 executed OK

Thread-3 executed OK

Thread-0 executed OK