最后是ThreadPool,负责管理所有的服务器线程,还可以动态增加和减少线程数:
package com.crackj2ee.thread;
import java.util.*;
public class ThreadPool extends ThreadGroup {
private List threads = new LinkedList();
private TaskQueue queue;
public ThreadPool(TaskQueue queue) {
super("Thread-Pool");
this.queue = queue;
}
public synchronized void addWorkerThread() {
Thread t = new WorkerThread(this, queue);
threads.add(t);
t.start();
}
public synchronized void removeWorkerThread() {
if(threads.size()>0) {
WorkerThread t = (WorkerThread)threads.remove(0);
t.shutdown();
}
}
public synchronized void currentStatus() {
System.out.println("-----------------------------------------------");
System.out.println("Thread count = " + threads.size());
Iterator it = threads.iterator();
while(it.hasNext()) {
WorkerThread t = (WorkerThread)it.next();
System.out.println(t.getName() + ": " + (t.isIdle() ? "idle" : "busy"));
}
System.out.println("-----------------------------------------------");
}
}
currentStatus()方法是为了方便调试,打印出所有线程的当前状态。
最后,Main负责完成main()方法:
package com.crackj2ee.thread;
public class Main {
public static void main(String[] args) {
TaskQueue queue = new TaskQueue();
ThreadPool pool = new ThreadPool(queue);
for(int i=0; i<10; i++) {
queue.putTask(new CalculateTask());
queue.putTask(new TimerTask());
}
pool.addWorkerThread();
pool.addWorkerThread();
doSleep(8000);
pool.currentStatus();
pool.addWorkerThread();
pool.addWorkerThread();
pool.addWorkerThread();
pool.addWorkerThread();
pool.addWorkerThread();
doSleep(5000);
pool.currentStatus();
}
private static void doSleep(long ms) {
try {
Thread.sleep(ms);
}
catch(InterruptedException ie) {}
}
}
main()一开始放入了20个Task,然后动态添加了一些服务线程,并定期打印线程状态,运行结果如下:
worker-0 start.
[CalculateTask 0] start...
worker-1 start.
[TimerTask 0] start...
[TimerTask 0] done.
[CalculateTask 1] start...
[CalculateTask 0] done.
[TimerTask 1] start...
[CalculateTask 1] done.
[CalculateTask 2] start...
[TimerTask 1] done.
[TimerTask 2] start...
[TimerTask 2] done.
[CalculateTask 3] start...
-----------------------------------------------
Thread count = 2
worker-0: busy
worker-1: busy
-----------------------------------------------
[CalculateTask 2] done.
[TimerTask 3] start...
worker-2 start.
[CalculateTask 4] start...
worker-3 start.
[TimerTask 4] start...
worker-4 start.
[CalculateTask 5] start...
worker-5 start.
[TimerTask 5] start...
worker-6 start.
[CalculateTask 6] start...
[CalculateTask 3] done.
[TimerTask 6] start...
[TimerTask 3] done.
[CalculateTask 7] start...
[TimerTask 4] done.
[TimerTask 7] start...
[TimerTask 5] done.
[CalculateTask 8] start...
[CalculateTask 4] done.
[TimerTask 8] start...
[CalculateTask 5] done.
[CalculateTask 9] start...
[CalculateTask 6] done.
[TimerTask 9] start...
[TimerTask 6] done.
[TimerTask 7] done.
-----------------------------------------------
Thread count = 7
worker-0: idle
worker-1: busy
worker-2: busy
worker-3: idle
worker-4: busy
worker-5: busy
worker-6: busy
-----------------------------------------------
[CalculateTask 7] done.
[CalculateTask 8] done.
[TimerTask 8] done.
[TimerTask 9] done.
[CalculateTask 9] done.
分享到:
相关推荐
书中包含Java线程的介绍导读、12个重要的线程设计模式和全书总结以及丰富的附录内容。第一章相关线程设计模式的介绍,都举一反三使读者学习更有效。最后附上练习问题,让读者可以温故而知新,能快速地吸收书中的...
java多线程设计模式详解,包括了单线程,生产者和消费者,各种线程方法的解释!
java多线程设计模式详解
java多线程设计模式详解.rar书籍java多线程设计模式详解.rar
java多线程设计模式详解PDF及源码,java多线程设计模式详解PDF及源码,java多线程设计模式详解PDF及源码
java多线程设计模式详解+源码,多线程编程的经典书籍,赶紧下吧!
这本书是很经典的! 如何充分利用系统资源,如何让你的软件跑得更...该书详细阐述了JAVA多线程的设计、开发并配有测试源代码,更值得注意是将多线程设计与设计模式结合起来,供我们设计大型服务器的多线程提供了帮助。