从客户端发送到服务器，从服务器发送到客户端在java中

Question

我开发了将表单客户端发送到服务器的代码，然后服务器必须将它从客户端接收到的内容再次发送到客户端。但在我的代码中，服务器只接收消息，但不会再次发送。我不知道是什么问题

这是我的客户端代码

public class Client implements Runnable{ 

private static Socket s = null; 
//private static BufferedOutputStream fromUser = null; 
private static DataInputStream fromServer = null; 
private static InputStreamReader input = new InputStreamReader(System.in); 
private static InputStreamReader inputstreamreader = null; 
private static BufferedReader bufferedreader = null; 
private static DataOutputStream fromUser = null; 
private static int chara = 0; 
private static String line = null; 
static int port = 0; 
static String host = null; 

//connect to server 
@Override 
public void run() { 
     try { 
inputstreamreader = new InputStreamReader(s.getInputStream()); 
bufferedreader = new BufferedReader(inputstreamreader); 

    //charr = fromClient.read(); 
    while(true){ 
    if ((line = bufferedreader.readLine()) != null){ 
     System.out.println(line);} 
     if(line.equals(-1)){ 
     break; 
     } 


}//end while 
}catch(NullPointerException e) { 
    // do something other 
} 
catch (IOException e) { 
    System.out.println(e); 
} 

}//end the run 


//constructor with two arguments 
public Client(String host, int port){ 
try{ 
s = new Socket (host,port); 
} 
catch(Exception e){} 
} 
//send message to from Client to Server 

public static void sendToServer(){ 
try{ 
fromUser =new DataOutputStream (new BufferedOutputStream(s.getOutputStream())); 
chara =input.read(); 
while(true){ 
if (chara == '~'){ 
break;} 
fromUser.write(chara); 
fromUser.flush(); 
chara =input.read(); 
}//end while 
} 
catch (IOException e) { 
    System.out.println(e); 
} 
}//end send message 

我试图用线程接收消息，但也不起作用。我尝试没有线程它不工作。

public static void main(String [] args){ 

host = args[0]; 
port = Integer.parseInt(args[1]); 

System.out.println("Start connection ....."); 
Client client = new Client(host,port); 
    Thread thread = new Thread(client); 
    thread.start(); 
//connect(host,port); 


client.sendToServer(); 

client.close(); 



}//end main 

，这是我的服务器代码

public class Server extends Thread{ 

private static Socket s = null; 
private static ServerSocket ss = null; 
private static DataOutputStream fromUser = null; 
private static DataInputStream fromClient = null; 
private static InputStreamReader input = new InputStreamReader(System.in); 
private static InputStreamReader inputstreamreader = null; 
private static BufferedReader bufferedreader = null; 
static String line=null; 
static String sendC; 
private static int chara = 0; 
static int port = 0; 

//connect to server 
static void connect(int port){ 
try{ 
    ss = new ServerSocket (port); 
    System.out.println("Listening on port "+port+"..."); 
    s = ss.accept(); 
System.out.println("Has been connected ....."); 
    } 
    catch (IOException e) { 
     System.out.println(e); 
    } 

}//end of the connection method 
//send message to from Client to Server 
public static void sendToClient(String text){ 
try{ 
fromUser =new DataOutputStream (new BufferedOutputStream(s.getOutputStream())); 
sendC =text; 
fromUser.write(sendC.getBytes()); 
fromUser.flush(); 

} 
catch (IOException e) { 
    System.out.println(e); 
} 
}//end send message 

public static void receiveFromClient(){ 
try { 
inputstreamreader = new InputStreamReader(s.getInputStream()); 
bufferedreader = new BufferedReader(inputstreamreader); 

    //charr = fromClient.read(); 
    while(true){ 
    if ((line = bufferedreader.readLine()) != null){ 
     System.out.println(line); 
     sendToClient(line);} 
     if(line.equals(-1)){ 
     break; 
     } 
     }//end while 
}catch(NullPointerException e) { 
    // do something other 
} 
catch (IOException e) { 
    System.out.println(e); 
} 
}//end send message 

这是服务器的主要方法

public static void main(String [] args){ 
port = Integer.parseInt(args[0]); 
System.out.println("Start connection ....."); 
connect(port); 
receiveFromClient(); 
//sendToClient(); 
close(); 



}//end main 

我没有在Java中的知识很多特别是关于插座 感谢您帮助

Answer 1

一个简单的搜索一个java回显服务器显示这个

public class EchoServer { 

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

     // create socket 
     int port = 4444; 
     ServerSocket serverSocket = new ServerSocket(port); 
     System.err.println("Started server on port " + port); 

     // repeatedly wait for connections, and process 
     while (true) { 

      // a "blocking" call which waits until a connection is requested 
      Socket clientSocket = serverSocket.accept(); 
      System.err.println("Accepted connection from client"); 

      // open up IO streams 
      In in = new In (clientSocket); 
      Out out = new Out(clientSocket); 

      // waits for data and reads it in until connection dies 
      // readLine() blocks until the server receives a new line from client 
      String s; 
      while ((s = in.readLine()) != null) { 
       out.println(s); 
      } 

      // close IO streams, then socket 
      System.err.println("Closing connection with client"); 
      out.close(); 
      in.close(); 
      clientSocket.close(); 
     } 
    } 
} 

看到http://introcs.cs.princeton.edu/java/84network/EchoServer.java.html