java写的简单线程池

import java.util.*;
import java.io.*;
import java.net.*;
//线程池类，创建处于使用中和空闲中的进程队列
class ThreadPool{
        private Vector freeThreads = new Vector();
        private Vector inUseThreads = new Vector();//Vetcor对象
        private static int value = 100;//线程池的最大并发线程数
        public ThreadPool(){
                fillpool(value);
                }
        private void fillpool(int poolsize){
                for(int i = 0;i<poolsize;i++){
                        //this为所处的类内的当前该类对象，当前为ThreadPool类对象
                        PoolableThread pt=new PoolableThread(this);//传入线程池对象
                        pt.start();//启动线程
                        freeThreads.add(pt);//加入空闲线程队列
                        }
                        try{
                                Thread.sleep(100);//线程休眠
                        }catch(InterruptedException ie){}
                }
        public synchronized void runTask(Runnable task){//运行Runnable接口
             if(freeThreads.isEmpty()){
             throw new RuntimeException("All threads are in use");//空闲线程为空，抛出异常
             }
             PoolableThread t = (PoolableThread)freeThreads.remove(0);//提取空闲线程
             inUseThreads.add(t);//加入到使用状态队列当中
             t.setTask(task);//传入Runnable接口类型对象
             }
        synchronized void free(PoolableThread t){
        inUseThreads.remove(t);//释放使用状态队列
        freeThreads.add(t);//加入到空闲队列中
        }
}      //PoolableThread进程类
        class PoolableThread extends Thread{
        Runnable task = null;
        ThreadPool pool;
        PoolableThread(ThreadPool pool){
        this.pool = pool;//PoolableThread类当前对象（this）的pool变量初始化
        }
        synchronized void setTask(Runnable task){
        this.task = task;//PoolableThread类当前对象（this）的task变量初始化
        notify();//唤醒等待进程
        }
        synchronized void executeTasks(){//等待进程被唤醒后执行Runnable接口
        for(; ; ){
          try{
        if (task == null){
        wait();//如果Runnable对象实例task为空，进入等待状态
        }
          }catch (InterruptedException ex){}
        task.run();//执行Runnable接口run方法
        task = null;//执行完后释放Runnable对象task
        pool.free(this);//释放
        }
        }
        public void run(){//PoolableThread进程类run()方法
        executeTasks();
        }
        }
        //Runnable接口类
        public class PoolTest implements Runnable{
        public static ThreadPool tp = new ThreadPool();//线程池类对象
        Socket socket;
        BufferedReader in;
        PrintWriter out;
        public PoolTest(Socket socket)throws IOException{
        this.socket = socket;//初始化socket
        this.in = new BufferedReader(new InputStreamReader(socket.getInputStream()));//建立输入流管道
        this.out = out=new PrintWriter(new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())),true);//建立输出流管道
        tp.runTask(this);//运行Runnable类接口
        try {Thread.sleep(100);}catch (Exception e){}
        }

        public static void main(String[] args)throws IOException{
        ServerSocket s=new ServerSocket(8080);//初始化服务器端口
        int i = 0 ;
        System.out.println("Server start.."+s);
        try{
        while(true){Socket socket=s.accept();//无限监听客户请求
                      System.out.println("Connectino accept:"+socket+" "+i);
                      i++;
                  try{
                      new PoolTest(socket);//调用Runnable接口进程
                  }catch(IOException e){socket.close();}
                }
        }finally{s.close();}
      }
     public void run(){
       try{ while(true){
          String str=in.readLine();//读取输入流
          if(str.equals("end"))break;
          System.out.println("Echo ing :"+str);
          }  System.out.println("Close");
       }catch(IOException e){}
       finally {try{socket.close();}
                     catch(IOException e){}
       }
}
}//服务器程序结束

请各位朋友指正