Java自定义多线程服务器

// multi.MultiServer.java
package multi;
import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.Socket;
public class MultiServer {
private int port = 8000;
private int backlog = 42;
private ServerSocket server_socket;
private ThreadPool threadPool;
private final int POOL_SIZE = 7;

public MultiServer()throws IOException{
server_socket = new ServerSocket();
server_socket.setReuseAddress(true);
server_socket.bind(new InetSocketAddress(port),backlog);
int system_cpu_total = Runtime.getRuntime().availableProcessors();
threadPool = new ThreadPool(POOL_SIZE * system_cpu_total);
System.out.println("--- server started! ---");
}
public void service(){
while(true){
try{
Socket socket = server_socket.accept();
threadPool.execute(new WorkHandler(socket));
} catch(Exception e){
e.printStackTrace();
}
}
}
public static void main(String[] args)throws Exception {
MultiServer server = new MultiServer();
server.service();
}
}
// multi.ThreadPool.java
package multi;
import java.util.LinkedList;
public class ThreadPool extends ThreadGroup{
private static int threadPoolId;
private boolean isClosed = false;
private LinkedList<Runnable> workQueue;

public ThreadPool(int poolSize){
super("ThreadPool-" + (threadPoolId++));
setDaemon(true);
workQueue = new LinkedList<Runnable>();
for(int i=0;i<poolSize;i++){
new WorkThread(this,i).start(); // 启动工作者线程
}
}

public synchronized void execute(Runnable task){
if(isClosed){
throw new IllegalStateException("The " + getName()
+ " has closed!");
}
if(task != null){
workQueue.add(task);
// 一次只有一个线程取任务[getTask() 被 synchronized 修饰]
// 所有此处没有使用notifyAll();