Java网络编程精解之ServerSocket用法详解二

while (true) {

Socket socket=null;

try {

socket = serverSocket.accept();     //接收客户连接

//从Socket中获得输入流与输出流，与客户通信

…

}catch (IOException e) {

e.printStackTrace();

}finally {

try{

if(socket!=null)socket.close();    //断开连接

}catch (IOException e) {e.printStackTrace();}

}

}

public void service() {

while (true) {

Socket socket=null;

try {

socket = serverSocket.accept();      //接收客户连接

Thread workThread=new Thread(new Handler(socket));   //创建一个工作线程

workThread.start();        //启动工作线程

}catch (IOException e) {

e.printStackTrace();

}

}

}

package multithread1;

import java.io.*;

import java.net.*;

public class EchoServer {

private int port=8000;

private ServerSocket serverSocket;public EchoServer() throws IOException {

serverSocket = new ServerSocket(port);

System.out.println("服务器启动");

}public void service() {

while (true) {

Socket socket=null;

try {

socket = serverSocket.accept();      //接收客户连接

Thread workThread=new Thread(new Handler(socket));   //创建一个工作线程

workThread.start();        //启动工作线程

}catch (IOException e) {

e.printStackTrace();

}

}

}public static void main(String args[])throws IOException {

new EchoServer().service();

}

}class Handler implements Runnable{       //负责与单个客户的通信

private Socket socket;

public Handler(Socket socket){

this.socket=socket;

}

private PrintWriter getWriter(Socket socket)throws IOException{…}

private BufferedReader getReader(Socket socket)throws IOException{…}

public String echo(String msg) {…}

public void run(){

try {

System.out.println("New connection accepted " +

socket.getInetAddress() + ":" +socket.getPort());

BufferedReader br =getReader(socket);

PrintWriter pw = getWriter(socket);

String msg = null;

while ((msg = br.readLine()) != null) {     //接收和发送数据，直到通信结束

System.out.println(msg);

pw.println(echo(msg));

if (msg.equals("bye"))

break;

}

}catch (IOException e) {

e.printStackTrace();

}finally {

try{

if(socket!=null)socket.close();       //断开连接

}catch (IOException e) {e.printStackTrace();}

}

}

}

package multithread2;

import java.util.LinkedList;

public class ThreadPool extends ThreadGroup {

private boolean isClosed=false;     //线程池是否关闭

private LinkedList workQueue;   //表示工作队列

private static int threadPoolID;     //表示线程池ID

private int threadID;      //表示工作线程IDpublic ThreadPool(int poolSize) {    //poolSize指定线程池中的工作线程数目

super("ThreadPool-" + (threadPoolID++));

setDaemon(true);

workQueue = new LinkedList();   //创建工作队列

for (int i=0; i
new WorkThread().start();     //创建并启动工作线程

}

/** 向工作队列中加入一个新任务，由工作线程去执行该任务 */

public synchronized void execute(Runnable task) {

if (isClosed) {      //线程池被关则抛出IllegalStateException异常

throw new IllegalStateException();

}

if (task != null) {

workQueue.add(task);

notify();       //唤醒正在getTask()方法中等待任务的工作线程

}

}/** 从工作队列中取出一个任务，工作线程会调用此方法 */

protected synchronized Runnable getTask()throws InterruptedException{

while (workQueue.size() == 0) {

if (isClosed) return null;

wait();       //如果工作队列中没有任务，就等待任务

}

return workQueue.removeFirst();

}/** 关闭线程池 */

public synchronized void close() {

if (!isClosed) {

isClosed = true;

workQueue.clear();     //清空工作队列

interrupt();       //中断所有的工作线程，该方法继承自ThreadGroup类

}

}/** 等待工作线程把所有任务执行完 */

public void join() {

synchronized (this) {

isClosed = true;

notifyAll();       //唤醒还在getTask()方法中等待任务的工作线程

}Thread[] threads = new Thread[activeCount()];

//enumerate()方法继承自ThreadGroup类，获得线程组中当前所有活着的工作线程

int count = enumerate(threads);

for (int i=0; i      try {

threads[i].join();     //等待工作线程运行结束

}catch(InterruptedException ex) { }

}

}/**  内部类：工作线程  */

private class WorkThread extends Thread {

public WorkThread() {

//加入到当前ThreadPool线程组中

super(ThreadPool.this,"WorkThread-" + (threadID++));

}public void run() {

while (!isInterrupted()) {  //isInterrupted()方法继承自Thread类，判断线程是否被中断

Runnable task = null;

try {       //取出任务

task = getTask();

}catch (InterruptedException ex){}// 如果getTask()返回null或者线程执行getTask()时被中断，则结束此线程

if (task == null) return;

try { //运行任务，异常在catch代码块中捕获

task.run();

} catch (Throwable t) {

t.printStackTrace();

}

}      //#while

}       //#run()

}       //#WorkThread类

}