Java 示例 - 多线程服务器

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  问题描述

  如何创建多线程服务器？
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  解决方案

  下面的例子演示了如何使用 Socket 类的 ssock.accept() 方法和 ServerSocket 类的 MultiThreadServer(socketname) 方法创建一个多线程服务器。

  
  import java.io.IOException;
  import java.io.PrintStream;
  import java.net.ServerSocket;
  import java.net.Socket;
  public class MultiThreadServer implements Runnable {
     Socket csocket;
     MultiThreadServer(Socket csocket) {
        this.csocket = csocket;
     }
     public static void main(String args[]) throws Exception { 
        ServerSocket ssock = new ServerSocket(1234);
        System.out.println("Listening");
        
        while (true) {
           Socket sock = ssock.accept();
           System.out.println("Connected");
           new Thread(new MultiThreadServer(sock)).start();
        }
     }
     public void run() {
        try {
           PrintStream pstream = new PrintStream(csocket.getOutputStream());
           for (int i = 100; i >= 0; i--) {
              pstream.println(i + " bottles of beer on the wall");
           }
           pstream.close();
           csocket.close();
        } catch (IOException e) {
           System.out.println(e);
        }
     }
  }
  

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  结果

  上面的代码示例将产生以下结果。

  
  Listening
  Connected
  

  以下是如何创建多线程服务器的另一个示例。

  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStreamReader;
  import java.io.OutputStreamWriter;
  import java.io.PrintWriter;
  import java.net.ServerSocket;
  import java.net.Socket;
  import java.text.SimpleDateFormat;
  import java.util.Calendar;
   
  public class NewClass {
     ServerSocket myServerSocket;
     boolean ServerOn = true;
     public NewClass() { 
        try {
           myServerSocket = new ServerSocket(8888);
        } catch(IOException ioe) { 
           System.out.println("Could not create server socket on port 8888. Quitting.");
           System.exit(-1);
        } 
        
        Calendar now = Calendar.getInstance();
        SimpleDateFormat formatter = new SimpleDateFormat(
           "E yyyy.MM.dd 'at' hh:mm:ss a zzz");
        System.out.println("It is now : " + formatter.format(now.getTime()));
        
        while(ServerOn) { 
           try { 
              Socket clientSocket = myServerSocket.accept();
              ClientServiceThread cliThread = new ClientServiceThread(clientSocket);
              cliThread.start(); 
           } catch(IOException ioe) { 
              System.out.println("Exception found on accept. Ignoring. Stack Trace :"); 
              ioe.printStackTrace(); 
           }  
        } 
        try { 
           myServerSocket.close(); 
           System.out.println("Server Stopped"); 
        } catch(Exception ioe) { 
           System.out.println("Error Found stopping server socket"); 
           System.exit(-1); 
        } 
     }
     
     public static void main (String[] args) { 
        new NewClass();        
     } 
     
     class ClientServiceThread extends Thread { 
        Socket myClientSocket;
        boolean m_bRunThread = true; 
        public ClientServiceThread() { 
           super(); 
        } 
        
        ClientServiceThread(Socket s) { 
           myClientSocket = s; 
        } 
        
        public void run() { 
           BufferedReader in = null; 
           PrintWriter out = null; 
           System.out.println(
              "Accepted Client Address - " + myClientSocket.getInetAddress().getHostName());
           try { 
              in = new BufferedReader(
                 new InputStreamReader(myClientSocket.getInputStream()));
              out = new PrintWriter(
                 new OutputStreamWriter(myClientSocket.getOutputStream()));
              
              while(m_bRunThread) { 
                 String clientCommand = in.readLine(); 
                 System.out.println("Client Says :" + clientCommand);
                 
                 if(!ServerOn) { 
                    System.out.print("Server has already stopped"); 
                    out.println("Server has already stopped"); 
                    out.flush(); 
                    m_bRunThread = false;
                 } 
                 if(clientCommand.equalsIgnoreCase("quit")) {
                    m_bRunThread = false;
                    System.out.print("Stopping client thread for client : ");
                 } else if(clientCommand.equalsIgnoreCase("end")) {
                    m_bRunThread = false;
                    System.out.print("Stopping client thread for client : ");
                    ServerOn = false;
                 } else {
                    out.println("Server Says : " + clientCommand);
                    out.flush(); 
                 } 
              } 
           } catch(Exception e) { 
              e.printStackTrace(); 
           } 
           finally { 
              try { 
                 in.close(); 
                 out.close(); 
                 myClientSocket.close(); 
                 System.out.println("...Stopped"); 
              } catch(IOException ioe) { 
                 ioe.printStackTrace(); 
              } 
           } 
        } 
     } 
  }