socket通信程序中的问题

[hewenhao]

下面是两段程序，服务器端的和客户端的，现在的问题是：
当服务器端给客户端发数据之后，客户端好像接受不到，如果把//code for test之间的代码去掉，就可以实现客户端到服务器端的数据传送，难道逆向就不能了吗？


服务器段程序：
import java.io.*;
import java.net.*;

public class tcpServer {
public static void main(String[] args)
{
int port=1500;
ServerSocket server_socket;
BufferedReader input;
//code for test
BufferedReader input1;
PrintWriter output;
String lineToSend;
//code for test
try
{
server_socket=new ServerSocket(port);
System.out.println("server listening on port:"+server_socket.getLocalPort());

while(true)
{
Socket socket=server_socket.accept();
System.out.println("New connection at "+socket.getInetAddress()+":"+socket.getPort());
input=new BufferedReader(new InputStreamReader(socket.getInputStream()));
//code for test
input1=new BufferedReader(new InputStreamReader(System.in));
output=new PrintWriter(socket.getOutputStream());
//code for test
try
{
while(true)
{

//code for test
lineToSend=input1.readLine();
System.out.println(lineToSend);
if(lineToSend.equals("end"))
{
System.out.println("game over");
break;
}
System.out.println("begin");
output.println(lineToSend);
System.out.println("end");
//code for test

String message=input.readLine();

if(message==null)
{
System.out.println("message equals null");
break;
}

System.out.println(message);

}
}
catch(IOException e)
{
System.out.println(e);
}

try
{
socket.close();
System.out.println("socket closed by client");
}
catch(IOException e)
{
System.out.println(e);
}
}
}
catch(IOException e)
{
System.out.println(e);
}
}
}

客户端程序：
import java.io.*;
import java.net.*;

public class tcpClient
{
public static void main(String[] args)
{
int port=1500;
String server="localhost";
Socket socket=null;
String lineToSend;
BufferedReader input;
PrintWriter output;
int ERROR=1;
//code for test
BufferedReader input1;
//code for test

//connect to the server
try
{
socket=new Socket(server,port);
System.out.println("connected with server "+socket.getInetAddress()+":"+socket.getPort());
}
catch(UnknownHostException e)
{
System.out.println(e);
System.exit(ERROR);
}
catch(IOException e)
{
System.out.println(e);
System.exit(ERROR);
}

try
{
input=new BufferedReader(new InputStreamReader(System.in));
output=new PrintWriter(socket.getOutputStream(),true);
//code for test
input1=new BufferedReader(new InputStreamReader(socket.getInputStream()));
//code for test
while(true)
{

//code for test
System.out.println("begin");
String message=input1.readLine();
System.out.println("end");
if(message==null)
{
System.out.println("message equals null");
break;
}
System.out.println(message);
//code for test

lineToSend=input.readLine();

if(lineToSend.equals("end"))
{
System.out.println("game over");
break;
}
output.println(lineToSend);

}
}
catch(IOException e)
{
System.out.println(e);
}

try
{
socket.close();
System.out.println("socket closed");
}
catch(IOException e)
{
System.out.println(e);
}

}
}

[hewenhao]

数据只能从客户端向服务器端发送吗？

[youbin_]

可以双向的啊，就是用一种交互的机制，不能同时都等在那里

[daimon0316]

双向通信完全可以呀，互为服务端嘛，起两个端口，现在好多短消息网关就是这个样子

[hewenhao]

为什么我从服务器端发数据，客户端接收不到呢？改写的程序如下：
服务器端：
import java.io.*;
import java.net.*;

public class tcpServer {
public static void main(String[] args)
{
int port=3024;
ServerSocket server_socket;
BufferedReader input;
PrintWriter output;
String lineToSend;
try
{
server_socket=new ServerSocket(port);
System.out.println("server listening on port:"+server_socket.getLocalPort());


while(true)
{
Socket socket=server_socket.accept();
System.out.println("New connection at "+socket.getInetAddress()+":"+socket.getPort());
input=new BufferedReader(new InputStreamReader(System.in));
output=new PrintWriter(socket.getOutputStream());
try
{
while(true)
{
lineToSend=input.readLine();
System.out.println(lineToSend);
if(lineToSend.equals("end"))
break;
output.print(lineToSend);
}
}
catch(IOException e)
{
System.out.println(e);
}

try
{
socket.close();
System.out.println("socket closed by client");
}
catch(IOException e)
{
System.out.println(e);
}

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

客户端：
import java.io.*;
import java.net.*;

public class tcpClient
{
public static void main(String[] args)
{
int port=3024;
String server="localhost";
Socket socket=null;
BufferedReader input;
int ERROR=1;
//connect to the server
try
{
socket=new Socket(server,port);
System.out.println("connected with server "+socket.getInetAddress()+":"+socket.getPort());
}
catch(UnknownHostException e)
{
System.out.println(e);
System.exit(ERROR);
}
catch(IOException e)
{
System.out.println(e);
System.exit(ERROR);
}

try
{
input=new BufferedReader(new InputStreamReader(socket.getInputStream()));

while(true)
{
System.out.println("begin");
String message=input.readLine();
System.out.println("end");
if(message==null)
break;
System.out.println(message);
}
}
catch(IOException e)
{
System.out.println(e);
}

try
{
socket.close();
System.out.println("socket closed");
}
catch(IOException e)
{
System.out.println(e);
}

}
}

[hewenhao]

自己顶一下！

[hewenhao]

哪位大哥帮忙看看啊，我谢你！

[youbin_]

大概看了下，应该是客户端和服务端都在等待接收数据，结果是死等在那里了。
应该是一方收到信息后要发出些东西让对方接收，再进行判断，要不就只作接收！

[lfcai]

呵呵
好难看呀
我以前也遇到这样的问题过
后来在客户端与服务器端都重新启动了一个线程以后就解决了

[hupo1007]

楼主试下在客户端开个线程去accept服务器的响应呢?好像没有这个唉.

[hewenhao]

必须采用多线程才能解决这个问题，是吗？

[youbin_]

如果不用交互就不用！

[daimon0316]

服务器端接收到请求就将消息返回给客户端，你这个input、input1有点乱，你能细说一下不

[hewenhao]

是不是只有accept响应的那一段能接收数据啊？