java ServerSocket

public Socket accept() //等待连接,该方法阻塞
public void close() //关闭服务器套接字

ServerSocket只连一次的程序

/* this is serversocket */
package test;

import java.io.*;
import java.net.*;

class ServerOne extends Thread{
        private Socket socket;
        private BufferedReader in;
        private PrintWriter out;
        public ServerOne(Socket s) throws IOException{
                socket = s;
                in =
                  new BufferedReader(
                        new InputStreamReader(
                                socket.getInputStream(),"UTF-8"));
                //Enbale auto-flush;
                out =
                  new PrintWriter(
                        new BufferedWriter(
                                new OutputStreamWriter(
                                        socket.getOutputStream(),"UTF-8")),true);
                start();
        }
        public void run(){
        try{
                while(true){
                        String str = in.readLine();
                        if(str.equals("END")) break;
                        System.out.println("Echoing:" + socket.getInetAddress());
                        out.println("str");
                        }
           }catch(IOException e){
           }finally{
                try{
                        socket.close();
                }catch(IOException e){
                }
           }
        }
}
public class MultiServer{
        static final int PORT = 5000;
        public static void main(String[] args)throws IOException{
                ServerSocket s = new ServerSocket(PORT);
                System.out.println("Server Started");
                try{
                  while(true){
                        Socket socket = s.accept();
                        try{
                          new ServerOne(socket);
                        }catch(IOException e){
                         socket.close();
                        }
                   }
                }finally{
                  s.close();
                }

        }}

多服务端程序实例

/* this is serversocket */
package socket;

import java.io.*;
import java.net.*;

class ServerOne extends Thread{
        private Socket socket;
        private BufferedReader in;
        private PrintWriter out;
        public ServerOne(Socket s) throws IOException{
                socket = s;
                in =
                  new BufferedReader(
                        new InputStreamReader(
                                socket.getInputStream(),"UTF-8"));
                //Enbale auto-flush;
                out =
                  new PrintWriter(
                        new BufferedWriter(
                                new OutputStreamWriter(
                                        socket.getOutputStream(),"UTF-8")),true);
                start();
        }
        public void run(){
        try{
                while(true){
                        String str = in.readLine();
                        if(str.equals("END")) break;
                        System.out.println("Echoing:" + socket.getInetAddress() + socket.getPort());
                        out.println(str);
                        }
           }catch(IOException e){
           }finally{
                try{
                        socket.close();
                }catch(IOException e){
                }
           }
        }
}
public class MultiServer{
        static final int PORT = 5000;
        public static void main(String[] args)throws IOException{
                ServerSocket s = new ServerSocket(PORT);
                System.out.println("Server Started");
                try{
                  while(true){
                        Socket socket = s.accept();
                        try{
                          new ServerOne(socket);
                        }catch(IOException e){
                         socket.close();
                        }
                   }
                }finally{
                  s.close();
                }
         }
}

规定线程个数的服务器

//: MultiJabberClient.java
// Client that tests the MultiJabberServer
// by starting up multiple clients.
import java.net.*;
import java.io.*; 

class JabberClientThread extends Thread {
  private Socket socket;
  private BufferedReader in;
  private PrintWriter out;
  private static int counter = 0;
  private int id = counter++;
  private static int threadcount = 0;
  public static int threadCount() {
    return threadcount;
  }
  public JabberClientThread(InetAddress addr) {
    System.out.println("Making client " + id);
    threadcount++;
    try {
      socket =
        new Socket(addr, MultiJabberServer.PORT);
    } catch(IOException e) {
      // If the creation of the socket fails,
      // nothing needs to be cleaned up.
    }
    try {
      in =
        new BufferedReader(
          new InputStreamReader(
            socket.getInputStream()));
       // Enable auto-flush:
      out =
        new PrintWriter(
          new BufferedWriter(
            new OutputStreamWriter(
              socket.getOutputStream())), true);
      start();
    } catch(IOException e) {
      // The socket should be closed on any
      // failures other than the socket
      // constructor:
      try {
        socket.close();
      } catch(IOException e2) {}
    }
    // Otherwise the socket will be closed by
    // the run() method of the thread.
  }
  public void run() {
    try {
      for(int i = 0; i < 25; i++) {
        out.println("Client " + id + ": " + i);
        String str = in.readLine();
        System.out.println(str);
      }
      out.println("END");
    } catch(IOException e) {
    } finally {
      // Always close it:
      try {
        socket.close();
      } catch(IOException e) {}
      threadcount--; // Ending this thread
    }
  }
} 

public class MultiJabberClient {
  static final int MAX_THREADS = 40;
  public static void main(String[] args)
      throws IOException, InterruptedException {
    InetAddress addr =
      InetAddress.getByName(null);
    while(true) {
      if(JabberClientThread.threadCount()
         < MAX_THREADS)
        new JabberClientThread(addr);
      Thread.currentThread().sleep(100);
    }
  }
} ///:~