gracefully ending socket communication
Hi. I have a client program and server program that communicate with a socket.
Here is the important code from the server:
ServerSocket server_socket =new ServerSocket(port);
while (true)
{
Socket socket = server_socket.accept();
InputStream is = socket.getInputStream();
BufferedReader br =new BufferedReader(new InputStreamReader(is));
PrintWriter out =new PrintWriter(socket.getOutputStream(),true);
String line;
while ( (line = br.readLine()) !=null)
{
out.println("server response");
}
br.close();
out.close();
}
Here is the important code from the client:
Socket client_sock =null;
BufferedReader in;
PrintWriter out;
try
{
client_sock =new Socket(ip_address, port);
out =new PrintWriter(client_sock.getOutputStream(),true);
in =new BufferedReader(new InputStreamReader(client_sock.getInputStream()));
String response ="";
out.println("client message");
String line;
while ( (line=in.readLine()) !=null)
{
response += line;
System.err.println(response);
}
}
catch (Exception e)
{
e.printStackTrace();
}
Here is my question: How do I actually send a "null" so that the loop
while ( (line=in.readLine()) !=null)
actually exits? I have tried sending a 0 (ascii null) and I have tried sending 23 (ascii end-of-transaction) and those don't work.
The only way I know how to stop the communication is to close the socket on one end, which results in an exception being thrown on the other end. I don't want to have a "Connection reset" exception. I just want the two parties to know that there are no more lines coming by reading the "null" and then gracefully move on.
Am I missing something about how socket communication is supposed to work? The way my code works now is that the server gets caught up in the readLine() loop waiting forever until I close the socket, which causes the server to barf.
