How to open specific port using java program

Question

Hello,
I want to open ,close port using java comm.plz help me how can i do it.is it possible
by using java program.later i want to use that specific port to accept the server socket connection .plz
help me.

Answer 1

i try this java program.*but it get block in accept method*.tht mean i m not able to make connection with port.
import java.sql.SQLException;
import java.io.IOException;
import java.net.ServerSocket;
import java.util.logging.Level;
import java.util.logging.Logger;
class MakeConn
     public final static int PORT = 7788;
public static java.net.Socket clientSocket = null;
public static java.io.PrintWriter pw = null; // socket output stream
public static java.io.BufferedReader br = null;
public static ServerSocket server_socket;
     public static void main(String[] args) throws SQLException
     try {
          server_socket = new ServerSocket(PORT);
clientSocket = server_socket.accept();
System.out.println("CLIENT>>>" + clientSocket);
     br = new java.io.BufferedReader(new java.io.InputStreamReader(clientSocket.getInputStream()));
pw = new java.io.PrintWriter(clientSocket.getOutputStream(), true);
String message = br.readLine().trim();
System.out.println("message is"+message);
pw.close(); // close everything
br.close();
clientSocket.close();
     catch (Exception ex) {
ex.printStackTrace();
}