简单网络;线程问题

Question

我想做一个简单的客户端服务器网络程序。最初，我没有同时运行服务器和客户端对象。命令提示符只会试图运行该程序。然后我决定使用threads。结果是一样的;我相信我必须在某处使用wait()和notify()，但我无法得到它。 服务器需要先运行，但它必须等待incoming Socket引用，然后才能继续。我相信在执行wait-and-notify机制之前，需要在这里和那里转移一些行。这是我的代码到目前为止 - ：

package networking; 
import java.net.*; 
import java.io.*; 
import java.util.Scanner; 

class Server implements Runnable 
{ 
     ServerSocket ss; 
    Socket incoming; 
    public void run() 
    { 
     try 
     { 
      ss = new ServerSocket(8189); 
      incoming = ss.accept(); 
      OutputStream outs = incoming.getOutputStream(); 
      InputStream ins = incoming.getInputStream(); 
      Scanner in = new Scanner(ins); 
      PrintWriter out = new PrintWriter(outs); 
      out.println("Hello, Bye to exit"); 
      out.println("This is the server program"); 
      out.println("It will echo client stuff"); 
      boolean done = false; 
      while(!done && in.hasNextLine()) 
      { 
       out.println("Echo: " + in.nextLine()); 
       if(in.nextLine().trim().equals("Bye")) 
        done = true; 
      } 
      incoming.close(); 
     } 
     catch(IOException e) 
     { 
      System.err.println(e.getMessage()); 
     } 
    } 
} 

class Client implements Runnable 
{ 
    Socket s; 
    public void run() 
    { 
     try 
     { 
      s = new Socket("localhost", 8189); 
      InputStream ins = s.getInputStream(); 
      OutputStream outs = s.getOutputStream(); 
      Scanner in = new Scanner(ins); 
      PrintWriter out = new PrintWriter(outs); 
      while(in.hasNextLine()) 
       System.out.println("Client: " + in.nextLine()); 
      out.println("Bye"); 
      s.close(); 
     } 
     catch(IOException e) 
     { 
      System.err.println(e.getMessage()); 
     } 
    } 
} 

public class Networking 
{ 
    public static void main(String... args) 
    { 
     Thread server = new Thread(new Server()); 
     Thread client = new Thread(new Client()); 
     server.start(); 
     client.start(); 
    } 
} 

任何提示和指针将不胜感激;我只需要点头（或更多）在正确的方向。

Answer 1

您的开放服务和客户端代码是正确的。但问题是在while循环中读取或写入处于死锁状态的数据。因为建立连接间服务器后，客户端正在等待对方在流中写入内容。试试这个。

class Server implements Runnable { 

    ServerSocket ss; 
    Socket incoming; 

    public void run() { 
     try { 
      System.out.println("Server STarted"); 
      ss = new ServerSocket(8189); 
      incoming = ss.accept(); 
      System.out.println("Client accepted"); 
      OutputStream outs = incoming.getOutputStream(); 
      InputStream ins = incoming.getInputStream(); 
      Scanner in = new Scanner(ins); 
      PrintWriter out = new PrintWriter(outs); 
      out.println("Hello, Bye to exit"); 
      out.println("This is the server program"); 
      out.println("It will echo client stuff"); 
      boolean done = false; 
      while (!done) { // && in.hasNextLine() 
//    out.println("Echo: " + in.nextLine()); 
//    if (in.nextLine().trim().equals("Bye")) { 
//     done = true; 
//    } 
       out.println("TEsting from server"); 
      } 
      incoming.close(); 
      System.out.println("End server"); 
     } catch (IOException e) { 
      System.err.println(e.getMessage()); 
     } 
    } 
}