JAVA线程池的实现 和 优先级设置

import java.util.LinkedList;import java.util.List; /** * * Title: LoonFramework * * * Description: * * * Copyright: Copyright (c) 2007 * * * Company: LoonFramework * * * @author chenpeng * @email：[e-mail] * @version 0.1 */public class ThreadPool {     private static ThreadPool instance = null;     // 优先级低    public static final int PRIORITY_LOW = 0;     // 普通    public static final int PRIORITY_NORMAL = 1;     // 高    public static final int PRIORITY_HIGH = 2;     // 用以保存空闲连接    private List[] _idxThreads;     // 关闭    private boolean _shutdown = false;     // 线程数量    private int _threadCount = 0;     // debug信息是否输出    private boolean _debug = false;     /** */    /**     * 返回ThreadPool实例     *     * @return     */    public static ThreadPool getInstance() {        if (instance == null) {            instance = new ThreadPool();        }        return instance;    }     // 初始化线程list    private ThreadPool() {        this._idxThreads = new List[] { new LinkedList(), new LinkedList(),                new LinkedList() };        this._threadCount = 0;    }     /** */    /**     * 同步方法，完成任务后将资源放回线程池中     *     * @param repool     */    protected synchronized void repool(Pooled repool) {        if (this._shutdown) {            if (this._debug) {                System.out.println("ThreadPool.repool():重设中……");            }            // 优先级别判定            switch (repool.getPriority()) {            case Thread.MIN_PRIORITY:                this._idxThreads[PRIORITY_LOW].add(repool);                break;            case Thread.NORM_PRIORITY:                this._idxThreads[PRIORITY_NORMAL].add(repool);                break;            case Thread.MAX_PRIORITY:                this._idxThreads[PRIORITY_HIGH].add(repool);                break;            default:                throw new IllegalStateException("没有此种级别");            }            // 通知所有线程            notifyAll();         } else {            if (this._debug) {                System.out.println("ThreadPool.repool():注销中……");            }            repool.shutDown();        }        if (this._debug) {            System.out.println("ThreadPool.repool():完成");        }    }     public void setDebug(boolean debug) {        this._debug = debug;    }     public synchronized void shutDown() {        this._shutdown = true;        if (this._debug) {            System.out.println("ThreadPool.shutDown():关闭中……");        }        for (int index = 0; index <= PRIORITY_NORMAL; index++) {            List threads = this._idxThreads[index];            for (int threadIndex = 0; threadIndex < threads.size(); threadIndex++) {                Pooled idleThread = (Pooled) threads.get(threadIndex);                idleThread.shutDown();            }        }        notifyAll();    }     /** */    /**     * 以指定的优先级启动线程     *     * @param target     * @param priority     */    public synchronized void start(Runnable target, int priority) {        Pooled thread = null;        List idleList = this._idxThreads[priority];        int idleSize = idleList.size();         if (idleSize > 0) {            int lastIndex = idleSize - 1;            thread = (Pooled) idleList.get(lastIndex);            idleList.remove(idleList);            thread.setTarget(target);        } else {            this._threadCount++;            thread = new Pooled(target, "Pooled->" + this._threadCount, this);            switch (priority) {             case PRIORITY_LOW:                thread.setPriority(Thread.MIN_PRIORITY);                break;            case PRIORITY_NORMAL:                thread.setPriority(Thread.NORM_PRIORITY);                break;            case PRIORITY_HIGH:                thread.setPriority(Thread.MAX_PRIORITY);                break;            default:                thread.setPriority(Thread.NORM_PRIORITY);            }            // 启动            thread.start();         }     }     /** */    /**     * 返回线程数量     *     * @return     */    public int getThreadsCount() {        return this._threadCount;    } }    /** * * Title: LoonFramework * * * Description: * * * Copyright: Copyright (c) 2007 * * * Company: LoonFramework * * * @author chenpeng * @email：[e-mail] * @version 0.1 */public class Pooled extends Thread {     private ThreadPool _pool;     private Runnable _target;     private boolean _shutdown = false;     private boolean _idle = false;     public Pooled(Runnable target) {        super(target);    }     public Pooled(Runnable target, String name) {        super(target, name);    }     public Pooled(Runnable target, String name, ThreadPool pool) {        super(name);        this._pool = pool;        this._target = target;    }     public Pooled(String name) {        super(name);    }     public Pooled(ThreadGroup group, Runnable target) {        super(group, target);    }     public Pooled(ThreadGroup group, Runnable target, String name) {        super(group, target, name);    }     public Pooled(ThreadGroup group, String name) {        super(group, name);    }     public Runnable getTarget() {        return this._target;    }     public boolean isIdle() {        return this._idle;    }     public void run() {        while (!this._shutdown) {            this._idle = false;            if (this._target != null) {                this._target.run();            }            this._idle = true;            try {                 this._pool.repool(this);                 synchronized (this) {                    wait();                }             } catch (InterruptedException ex) {                System.err.println(ex.getMessage());            }            this._idle = false;        }    }     public synchronized void setTarget(Runnable target) {        this._target = target;        notifyAll();    }     public synchronized void shutDown() {        this._shutdown = true;        notifyAll();    } }    //测试用类：package org.loon.framework.util.test;/** *//*** Title: LoonFramework* Description:线程池测试* Copyright: Copyright (c) 2007* Company: LoonFramework* @author chenpeng * @email：[e-mail]* @version 0.1*/public class ThreadPoolTest  {  private static Runnable createRunnable(final int id)  {    return new Runnable()  {        public void run()  {            System.out.println("线程" + id + ",运行 ");            try  {                Thread.sleep(1000);            }            catch (InterruptedException ex)  { }            System.out.println("线程" + id + ",结束");        }    };} public static void main(String[]args) {    ThreadPool pool=ThreadPool.getInstance();    pool.setDebug(true);     for (int i=1; i<=10; i++)  {         //根据数值，设定不同优先级         if(i%2==0) {                 pool.start(createRunnable(i), ThreadPool.PRIORITY_HIGH);         }else {                 pool.start(createRunnable(i), ThreadPool.PRIORITY_LOW);         }     }    System.out.println("线程池测试中……");    System.out.println("线程池线程总数:"+pool.getThreadsCount());    pool.shutDown();}}