Stopping an infinite loop

[Sean Casey]

I have created a simple web server, that goes in a continuous loop to accept connections. This works fine. But now I need to implement a feature to be able to stop the server and the infinite loop, and I wasn't sure how to do this. So I basically want to be able to type in a command to stop the server. My problem is that when I use a BufferedReader from System.in it just blocks if there is nothing to read, and in this instance I need the loop to continue. Here's the relevant code:

 
public static void main(String args[])throws Exception{
 
String clientRequest = null;
/* get the port number as the first argument */
ServerSocket welcomeSocket = new ServerSocket(Integer.parseInt(args[0]));
 

Socket connectionSocket;
BufferedReader inFromClient;
DataOutputStream outToClient;
 
BufferedReader control = new BufferedReader(
new InputStreamReader(System.in));
 



 
while(true){
/* loop continuously accepting connections */
 
 connectionSocket = welcomeSocket.accept();
 
/* create a BufferedReader object to read input */
inFromClient =
new BufferedReader(new InputStreamReader(
connectionSocket.getInputStream()));
 
/* create a DatatOutputStream object to write data */
outToClient =
new DataOutputStream(
connectionSocket.getOutputStream());
 
/* get the request from the client */
clientRequest = inFromClient.readLine();

/* create a Webserver object so we can manipulate the request */
WebServer app = new WebServer();
 
/* process the request */
       app.processRequest(connectionSocket, inFromClient, outToClient, clientRequest);


/* close the socket after the response is sent */
connectionSocket.close();
clientRequest = null;


}
 

 
}
}
 
  

How can I can I stop the server if need be?

Thanks for any help.

[Stefan Wagner]

What's about:

boolean letRun = true;
 
public void handleRequest ()
{
        while (letRun)
        {
                // do your work
        }
}
 
public void stopIt ()
{
        letRun = false;
}

And create a separate Thread, which reads from System.in, and on a 'stop' read, allow it to call 'stopIt ();'?

[Stan James]

My Wiki executes command classes when you post forms. One of the forms triggers a shutdown command that sets a variable that stops the loop just as shown above. So I can just navigate to a page and hit a button to shut it down from anywhere. I also made a little standalone program that pretends to be a browser and posts the shutdown form. Oh, it is secured - you have to log in with a userid that has shutdown permission.

[Tony Morris]

boolean letRun = true;

Note that this field should almost certainly be declared 'volatile'.

'almost certainly' because you almost certainly will be changing the value from a thread other than the one executing the while loop.

[somkiat puisungnoen]

You should use Thread/Runable to implement your program.

[Sean Casey]

thanks for all your help guys.