🚀 go-pugleaf

Hi all,

I am experimenting with sockets in Java. I have this little program that 
I've written:

------------------------------------------------------------------------
import java.net.*;
import java.io.*;

public class client
{
	public static void main (String[] args) throws IOException
	{
		String username = "foo";
		String password = "bar";
		Socket socket = new Socket ("mail", 110); // mail is my local POP3 server
		BufferedReader in = new BufferedReader (new InputStreamReader 
(socket.getInputStream()));
		PrintWriter out = new PrintWriter (new OutputStreamWriter 
(socket.getOutputStream()));

		// send command to server
		out.print (username + "\n");
		out.flush();

		// read response
		String response = "";
		String line;
		while ((line = in.readLine()) != null)
		{
			response += line;
		}
		
		System.out.println (response);

		in.close();
		out.close();
		socket.close();
	}
}
------------------------------------------------------------------------

Nothing too complicated, but there is a little problem: the while loop 
keeps blocking and does NOT return null when there's nothing to read 
from the socket.

If, for example, I replace the host to "www" (my local web server) and 
request to get an HTML file like:

out.print ("GET " + "/index.html" + " HTTP/1.0\n\n")
out.flush();

The while loop gets back the HTML file line by line, and when the entire 
file has been read, it does NOT block anymore.

I find it very strange that for the mail server example, the while loop 
does NOT return null when there's nothing to read from the socket and 
keeps blocking, while the web server example DOES return null and 
returns when there's nothing to read from the socket.

Does anyone know what the difference between the mail server and the web 
server is? Or, how to solve this problem?

Thanks in advance,

Cheers,

Joshua