java socket通信运行出错，请高手帮下忙，多谢。。。

Question

import java.net.*;
import java.io.*;
public class TestServer { //服务器端
public static void main(String[] args) {
try{

ServerSocket ss = new ServerSocket(6666);
Socket s = ss.accept();   
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
System.out.println("Client:" + br.readLine());
String str2 = br1.readLine();
while(!str2.equalsIgnoreCase("bye")){
bw.write(str2);
bw.flush();
//System.out.println("Server:" + str2);
System.out.println("Client:" + br.readLine());
str2 = br1.readLine();
}
br.close();
br1.close();
bw.close();
s.close();
ss.close();
}catch(IOException e){e.printStackTrace();}
}

}
import java.net.*;
import java.io.*;
public class TestClient{ //客服端
public static void main(String[] args) {
try{
    Socket s = new Socket("127.0.0.1",6666);
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));
 
String str = br1.readLine();    
while(!str.equalsIgnoreCase("bye")){
bw.write(str);
bw.flush();
//System.out.println("Client:" + str);
System.out.println("Server:" + br.readLine());
str = br1.readLine();
}

br.close();
br1.close();
bw.close();
s.close();
}catch(IOException e){e.printStackTrace();}

}
}

Answer 1

大家请使用cmd测试(cmd下，请去掉代码中的包名)，cmd下编译好后，cmd先启动server。再起一个cmd用于启动client。
//服务端：package com.expert58.socket; 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 ServerSocketDemo {        ServerSocket ss;    Socket socket;    BufferedReader in;    PrintWriter out;        public ServerSocketDemo(){       try {           ss=new ServerSocket(9999);           while(true){              socket=ss.accept();              String RemoteIP=socket.getInetAddress().getHostAddress();              String RemotePort=":"+socket.getLocalPort();              System.out.println("A client come in IP:"+RemoteIP+RemotePort);                            in=new BufferedReader(new InputStreamReader(socket.getInputStream()));              String line=in.readLine();              System.out.println("client send is:"+line);                            out=new PrintWriter(socket.getOutputStream(),true);              out.println("Your message received!");                            out.close();              in.close();              socket.close();           }       } catch (IOException e) {           e.printStackTrace();       }    }     public static void main(String[] args) {       new ServerSocketDemo();    } }  //客户端：package com.expert58.socket; import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.Socket;import java.net.UnknownHostException; public class ClientSocketDemo {     Socket socket;    BufferedReader in;    PrintWriter out;        public ClientSocketDemo(){       System.out.println("Try to connect to server:9999");       try {           socket=new Socket("127.0.0.1",9999);           System.out.println("Server connected!");           System.out.println("Please enter some character:");           BufferedReader line=new BufferedReader(new InputStreamReader(System.in));           out=new PrintWriter(socket.getOutputStream(),true);           out.println(line.readLine());                      in=new BufferedReader(new InputStreamReader(socket.getInputStream()));           System.out.println(in.readLine());                      out.close();           in.close();           socket.close();       } catch (UnknownHostException e) {           e.printStackTrace();       } catch (IOException e) {           e.printStackTrace();       }    }        public static void main(String[] args) {       new ClientSocketDemo();    } }

Answer 2

这样改改就好了，bw.write()写入字符串不带换行符'\n',br1.readLine()需要读入一行字符必须以换行符'\n'结尾，如果没有换行符'\n'，br1.readLine()迟迟不能获取一行数据，一直等待。
import java.net.*;
import java.io.*;
public class TestServer { //服务器端
public static void main(String[] args) {
try{ ServerSocket ss = new ServerSocket(9999); 
Socket s = ss.accept(); 
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in)); System.out.println("Client:" + br.readLine());
String str2 = br1.readLine();
while(!str2.equalsIgnoreCase("bye")){
bw.write(str2+"\n");
bw.flush();
//System.out.println("Server:" + str2); 
System.out.println("Client:" + br.readLine());
str2 = br1.readLine();
}
br.close();
br1.close();
bw.close();
s.close();
ss.close();
}catch(IOException e){
e.printStackTrace();}
}
}
import java.net.*;
import java.io.*;
public class TestClient{ //客服端
public static void main(String[] args) {
try{
Socket s = new Socket("127.0.0.1",9999);
BufferedReader br = new BufferedReader(new InputStreamReader(s.getInputStream()));
BufferedWriter bw= new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
BufferedReader br1 = new BufferedReader(new InputStreamReader(System.in));

String str = br1.readLine();   
while(!str.equalsIgnoreCase("bye")){
bw.write(str+"\n");
bw.flush();
//System.out.println("Client:" + str);
System.out.println("Server:" + br.readLine()); 
str = br1.readLine();
}

br.close();
br1.close();
bw.close();
s.close();
}catch(IOException e){
e.printStackTrace();
}

}
}

Answer 3

我这里有个UDP 接收消息端的， 但是调不对， 路过高手顺便看看
public class UDPReceive {
      private DatagramSocket socket;
      private DatagramPacket packet;
      private  int port;
      private boolean flag = true;
      
      public UDPReceive(int port){
       this.port = port;
     System.out.println("init port is  "+port);
      }   
      
      public void stopReceive(){
       flag= false;
       socket.close();
      }
      
      public String receiveMessage(){
       System.out.println("this is UDPReceiver");
       String msg ="15556";
       try {
       System.out.println("socket port 1  ? " +port);   
socket = new DatagramSocket(3602,InetAddress.getLocalHost());

System.out.println("receive adress "+socket.getInetAddress());  
System.out.println("try socket");
byte[] buffer = new byte[500];
       packet = new DatagramPacket(buffer, buffer.length);
       System.out.println("try packet");
       //循环接收 数据 
      // while(true){
       System.out.println("isbind ? " +socket.isBound());
       System.out.println("socket port 2 ? " +socket.getPort()); 
       socket.receive(packet);
       System.out.println("try receive");
       msg = new String(buffer, 0, packet.getLength());
       System.out.println("msg  "+msg);
       System.out.println("reveive message ");
    //   }       
} catch (SocketException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
       return msg;
      }
}
输出的时候
init port is  3602
this is UDPReceiver
socket port 1  ? 3602
receive adress null
try socket
try packet
isbind ? true
socket port 2 ? -1