java 线程的问题

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.io.*;
public class Server {
public static void main(String[] args)throws Exception{
if(args.length!=1){
System.out.println("用法：<端口>");
}
ServerSocket listen = new ServerSocket(Integer.parseInt(args[0]));
Socket s=listen.accept();
for(;;) {
[color=red]new SThread(s).start();[/color]
}

}
class SThread extends Thread{
    Socket sk;
    SThread(Socket s){
        sk=s;
    }
    public void run(){
    try{
        PrintWriter pw=new PrintWriter(sk.getOutputStream(),true);
        BufferedReader bf=new BufferedReader(new InputStreamReader(sk.getInputStream()));
        System.out.println("aaaaaaaaa");
        String message=null;
        while((message=bf.readLine())!=null){
            System.out.println("收到请求"+message);
            pw.println(message.toUpperCase());
            System.out.println();
        }
        System.out.println("bbbbbbbbbb");
        pw.close();
        bf.close();
        sk.close();

    } catch (NumberFormatException e) {
        // TODO 自动生成 catch 块
        e.printStackTrace();
    } catch (IOException e) {
        // TODO 自动生成 catch 块
        e.printStackTrace();
    }
    }
}

}

红色部分为什么在eclipse3.2里通不过呢？

我这里有段Socket通信的代码，希望对你有用
[code="java"]
package org.zergle.test.socket.server;

import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Date;
import java.util.ArrayList;
import java.util.List;

/**

• 服务器
• @author Johnson Lee

• */
  public class Server {
  private boolean running;
  private List clients;
  private ServerSocket svrSocket;

  public Server() {
  this.running = true;
  this.clients = new ArrayList();
  }

  public boolean isRunning() {
  return running;
  }

  public void run() {
  try {
  this.svrSocket = new ServerSocket(9090);
  System.err.println("Server started on "
  + new java.sql.Date(new Date().getTime()));
  while (running) {
  Socket cltSocket = this.svrSocket.accept();
  // 保存客户端的连接
  InetAddress ip = cltSocket.getInetAddress();
  int port = cltSocket.getPort();
  ConnectedClient client = new ConnectedClient(ip, port);
  this.clients.add(client);
  System.err.println(ip + " connected.");
  // 为每个客户端开一个线程
  new Thread(new RequestProcessor(this, cltSocket)).start();
  }
  } catch (Exception e) {
  this.running = false;
  }
  }

  /**

  • 连接到服务器端的客户端
  • @author Johnson Lee

  • */
    private static class ConnectedClient {
    public InetAddress ip;
    public int port;

    public ConnectedClient(InetAddress ip, int port) {
    super();
    this.ip = ip;
    this.port = port;
    }

    @Override
    public boolean equals(Object obj) {
    if (obj instanceof ConnectedClient) {
    ConnectedClient c = (ConnectedClient) obj;
    return c.ip.equals(this.ip) && c.port == this.port;
    }
    return false;
    }
    }

  /**

  • @param args */ public static void main(String[] args) { new Server().run(); } } [/code] [code="java"] package org.zergle.test.socket.server;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.SocketException;

/**

• 服务器端用于处理客户连接的处理器
• @author Johnson Lee

• */
  public class RequestProcessor implements Runnable {
  private Server server;
  private Socket socket;

  public RequestProcessor(Server server, Socket socket) {
  this.server = server;
  this.socket = socket;
  }

  @Override
  public void run() {
  if (this.server.isRunning() && this.socket != null
  && this.socket.isConnected()) {
  InetAddress ip = this.socket.getInetAddress();
  BufferedReader br = null;
  PrintWriter pw = null;
  String line = null;
  try {
  InputStream is = this.socket.getInputStream();
  br = new BufferedReader(new InputStreamReader(is));
  pw = new PrintWriter(this.socket.getOutputStream(), true);
  while ((line = br.readLine()) != null) {
  System.out.println(line);
  pw.println("服务器自动回复 ^_^ ");
  pw.flush();
  }
  } catch (SocketException e) {
  System.err.println("客户端 " + ip + " 已断开连接");
  } catch (IOException e) {
  e.printStackTrace();
  } finally {
  try {
  if (br != null) {
  br.close();
  br = null;
  }
  } catch (IOException e) {
  }
  }
  }
  }
  }
  [/code]
  [code="java"]
  package org.zergle.test.socket.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.net.Socket;

/**

• 客户端
• @author Johnson Lee

• */
  public class Client {
  private InetSocketAddress svrAddress;
  private Socket svrSocket;

  public Client(String host, int port) {
  this.svrAddress = new InetSocketAddress(host, port);
  }

  public void connect() throws IOException {
  this.svrSocket = new Socket(svrAddress.getAddress(), svrAddress
  .getPort());
  }

  public boolean isClosed() {
  return this.svrSocket == null || this.svrSocket.isClosed();
  }

  public InputStream getInputStream() throws IOException {
  return this.svrSocket.getInputStream();
  }

  public OutputStream getOutputStream() throws IOException {
  return this.svrSocket.getOutputStream();
  }

  /**

  • @param args */ public static void main(String[] args) { BufferedReader br = null; PrintWriter pw = null; String line = null; try { final Client c = new Client("127.0.0.1", 9090); c.connect();// 连接服务器 try { br = new BufferedReader(new InputStreamReader(System.in)); pw = new PrintWriter(c.getOutputStream(), true); new Thread(new ResponseProcessor(c)).start(); while (!c.isClosed()) { line = br.readLine(); pw.println(line); } } catch (IOException e) { e.printStackTrace(); } finally { try { if (br != null) { br.close(); br = null; } if (pw != null) { pw.close(); pw = null; } } catch (IOException e) { } } } catch (IOException e) { e.printStackTrace(); } }

}
[/code]
[code="java"]
package org.zergle.test.socket.client;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.SocketException;

/**

• 服务端响应处理器
• @author Johnson Lee

• */
  public class ResponseProcessor implements Runnable {
  private Client client;

  public ResponseProcessor(Client c) {
  super();
  this.client = c;
  }

  @Override
  public void run() {
  BufferedReader br = null;
  PrintWriter pw = null;
  String line = null;
  try {
  br = new BufferedReader(new InputStreamReader(client
  .getInputStream()));
  pw = new PrintWriter(System.out, true);
  while (!client.isClosed()) {
  line = br.readLine();
  pw.println(line);
  }
  } catch (SocketException e) {
  if (!client.isClosed()) {
  System.err.println(e);
  }
  } catch (IOException e) {
  e.printStackTrace();
  }
  }

}
[/code]

[code="java"]for(;;) {
new SThread(s).start();
} [/code]

这是一个死循环，会导致后面的任何代码都不能执行，程序也就无法退出！！

不好意思，看错了。

你的SThread 是内部类，不能那样实例化。这样就可以了：

[code="java"]import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
public static void main(String[] args) throws Exception {
if (args.length != 1) {
System.out.println("用法：<端口>");
}
ServerSocket listen = new ServerSocket(Integer.parseInt(args[0]));
Socket s = listen.accept();
for (;;) {
new SThread(s).start();
}

}

}

class SThread extends Thread {
Socket sk;

SThread(Socket s) {
    sk = s;
}

public void run() {
    try {
        PrintWriter pw = new PrintWriter(sk.getOutputStream(), true);
        BufferedReader bf = new BufferedReader(new InputStreamReader(sk
                .getInputStream()));
        System.out.println("aaaaaaaaa");
        String message = null;
        while ((message = bf.readLine()) != null) {
            System.out.println("收到请求" + message);
            pw.println(message.toUpperCase());
            System.out.println();
        }
        System.out.println("bbbbbbbbbb");
        pw.close();
        bf.close();
        sk.close();

    } catch (NumberFormatException e) {
        // TODO 自动生成 catch 块
        e.printStackTrace();
    } catch (IOException e) {
        // TODO 自动生成 catch 块
        e.printStackTrace();
    }
}

}[/code]

或者Main方法这样写：（内部类的实例化）
[code="java"] public static void main(String[] args) throws Exception {
Server server = new Server();
if (args.length != 1) {
System.out.println("用法：<端口>");
}
ServerSocket listen = new ServerSocket(Integer.parseInt(args[0]));
Socket s = listen.accept();
for (;;) {
server.new SThread(s).start();
}

}[/code]

final Socket s=listen.accept();