Server socket Hangs

Question

Hi,I am using the server socket in Java to listen on a port on a computer..
I am using the windows platform
I use ms vj++6.0
I am facing a peculiar problem.
about once in 10 messages received by my server socket,
The server socket hangs .
Hangs means it stops responding to the incoming message & so my application
is unable to take any action.
I used a port scanner & found that my server port is in a "close_wait"
state.
Can someone tell me the reason for this.
is it a problem with my server or can the client that sends the message be
also responsible for this type of an error.
Heres the code for my server
public server()
try
server = new ServerSocket(2156);
serverthread = new Thread(this);
serverthread.start();
catch(Exception e)
System.out.println("Cannot Start Thread" + e);
public synchronized void run()
try
while(true)
String line;
System.out.println("listening for the client");
fromclient = server.accept();
System.out.println("client has responded");
InputStreamReader isr = new
InputStreamReader(fromclient.getInputStream());
BufferedReader instream = new BufferedReader(isr);
PrintWriter ostream = new PrintWriter(new
BufferedOutputStream(fromclient.getOutputStream()));
System.out.println("talking to the client\n");
ostream.println("Hye Client");
ostream.println("Bye");
ostream.flush();
System.out.println("listening to the client \n");
String temp;
int count=0;
String ip="";
while((line=instream.readLine())!=null)
System.out.println(line+"\n");
if (line.equals("Bye"))
break;
if (line.equals(""))
continue;
else
System.out.println(line+"\n"); /*Print the line that has come in the
socket*/
ostream.close();
fromclient.close();
catch(Exception e)
System.out.println("Cannot listen to the client" + e);
I hope somebody can help me out .
Thanx in advance
Regards
Sanket Gupta

Answer 1

You don't seem to properly close the server socket any where. Here why don't you look at this skeleton. This may help you.
import java.net.*;
import java.io.*;
import java.util.*;
public class server
     static boolean listen = true;
     public static void main(String args[])
          try
               ServerSocket ss = new ServerSocket(2156);
               do
                    new serverThread(ss.accept()).start();
               while(listen);
               ss.close();
          catch(IOException e)
               System.err.println(e.getMessage());
     public static void shutdown()
          listen = false;
class serverThread extends Thread
     private Socket client;
     private String input;
     private BufferedReader in;
     private PrintWriter out;
     public serverThread(Socket c)
          client = c;
     public void run()
        try
          in = new BufferedReader(new InputStreamReader(client.getInputStream()));
          out = new PrintWriter(client.getOutputStream(),true);
          input = in.readLine();
          if(input.equals("Hello"))
               out.println("How are you doing?");
          else if(input.equals("shutdown!"))
               server.shutdown();
          else
               out.println("Bad Request!");
          in.close();
          out.close();
          client.close();
        catch(IOException e)
             System.err.println(e.getMessage());
}