warn if main() method invoked, not supported

examples/src/TcpExamples/TcpExample4HandlerThread.java

@@ -31,9 +31,9 @@ public class TcpExample4HandlerThread extends Thread
     /** The socket connection to a client */
     Socket socket;
     
-    /** The thread constructor creates the socket from
-     * a ServerSocket, and passes one to the thread
-     * responsible for handling the connection.
+    /** 
+     * The thread constructor creates the socket from a ServerSocket, waiting for the client to connect,
+     * and passes that socket when constructing the thread responsible for handling the connection.
      * 
      * @param socket The socket connection handled by this thread
      */
@@ -41,6 +41,15 @@ public class TcpExample4HandlerThread extends Thread
     {
         this.socket = socket;
     }
+    /**
+     * Program invocation and execution starts here - but is illegal and unwanted, so warn the unsuspecting user!
+     * @param args command-line arguments
+     */
+    public static void main(String[] args)
+    {
+        System.out.println ("*** TcpExample4HandlerThread is not a standalone executable progam.");
+        System.out.println ("*** Please run TcpExample4DispatchServer instead... now exiting.");
+    }
     
     /** Handles one connection. We add an artificial slowness
      * to handling the connection with a sleep(). This means