Play tcp CLOSE_WAIT state using java client / server

Question

Is there an easy way to reproduce the tcp state of CLOSE_WAIT using a java program?

I have an outdated Java application that has this problem, and I would like to be able to reproduce it so that I can check my fix.

thanks

Answer 1

The connection is in the CLOSE_WAIT state when the other side has closed the connection, but not on this side. Easy to reproduce:

// Client.java (will sleep in CLOSE_WAIT) import java.io.*; import java.net.*; public class Client { public static void main(String[] args) throws Exception { Socket socket = new Socket(InetAddress.getByName("localhost"), 12345); InputStream in = socket.getInputStream(); int c; while ((c = in.read()) != -1) { System.out.write(c); } System.out.flush(); // should now be in CLOSE_WAIT Thread.sleep(Integer.MAX_VALUE); } } // Server.java (sends some data and exits) import java.io.*; import java.net.*; public class Server { public static void main(String[] args) throws Exception { Socket socket = new ServerSocket(12345).accept(); OutputStream out = socket.getOutputStream(); out.write("Hello World\n".getBytes()); out.flush(); out.close(); } }