how to access user inputted port number client-server

[rotaryfreak]

Hello,

Im building a client-server application and the user needs to input the hostName and the portNumber the client application and needs to send the portnumber to the server application. I have everything set up (properly, i think) but i keep getting a connection error on the portNumber because my instantiated portNumber is 0; On the server side, when i System.out.prin t the portNumber, i see it is in fact 0. I know why this is happening; its happening because the server is running before the client and the server is taking the default client's port number, but i dont know how to get around this.
Is there a way to ask the server to wait for the portNumber until the user has inputted the value?

here is my code: (for now i am concerned with the hostName and port number, the rest of the code doesn't do much. its supposed to take a client's string and the server is supposed to upper-case it and return it to the server... that functionality isn't completely working yet)

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

class TCPServer {
	
	static ServerSocket welcomeSocket;
	static Socket connectionSocket;
	static BufferedReader inFromClient;
	static DataOutputStream outToClient;
	static String clientSentence;
	static String capitalizedSentence;
	
	public static int getTCPClientPortNo(){
		return TCPClient.portNumber;
	}
	
	public static void receiveServerConnection(){
		try{
			System.out.println("The port number is: " + getTCPClientPortNo());

			welcomeSocket = new ServerSocket(getTCPClientPortNo());
		}
		catch(Exception e){
			System.out.println("The port number is not available");
		}
	}
	
	public static void acceptSocketConnection(){
		while (true) {
			
			try{
				connectionSocket = welcomeSocket.accept();

				inFromClient = new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));

				outToClient = new DataOutputStream(connectionSocket.getOutputStream());

				clientSentence = inFromClient.readLine();
				System.out.println("clientSentence: " + clientSentence );

				capitalizedSentence = clientSentence.toUpperCase() + "\n";

				outToClient.writeBytes(capitalizedSentence);
			}
			catch(Exception e){
				System.out.println("Some error occured");

			}

		}
	}
	
	
	public static void main(String args[]) throws Exception {

		receiveServerConnection();
		
		
	}
}

and the client code is:

import java.io.*;
import java.net.*;
import java.util.*;

class TCPClient {
	
	static String host, port;
	static int portNumber = 0;
	static boolean connection = true;
	
	static Scanner kb = new Scanner(System.in);
	static Socket clientSocket;
	
	public static void getServerInfo(){
		try{
		System.out.print("Please enter the host name: ");
		BufferedReader hostInFromUser = new BufferedReader(new InputStreamReader(System.in));
		TCPClient.host = hostInFromUser.readLine();
		System.out.println("Host Name: " + TCPClient.host);

		
		System.out.print("Please enter the port number: ");
		BufferedReader portInFromUser = new BufferedReader(new InputStreamReader(System.in));
		TCPClient.port = portInFromUser.readLine();
		TCPClient.portNumber = Integer.parseInt(TCPClient.port);
		System.out.println("Port Number: " + TCPClient.portNumber);
		
		System.out.println("The client application will now attempt to connect to the server...");

		serverConnect(host, portNumber);
		}
		catch(Exception e){
			System.out.println("There has been an unexpecetd error, please try again...");

		}
	}
	
	public static void serverConnect(String hostName, int portNumber){
		try{
			clientSocket = new Socket(hostName, portNumber);
			System.out.println("Successfully connected to the server!");
			connection=true;

		}
		catch(Exception e){
			System.out.println("The connection to the server has been refused, please try again...");
			connection=false;
		}
	}

	public static void main(String args[]) throws Exception {

		String sentence;
		String modifiedSentence;
		do{
			TCPClient.getServerInfo();
					
		}
		while(TCPClient.connection ==false);
		{
			TCPClient.getServerInfo();
			
		}
		BufferedReader inFromUser = new BufferedReader(new InputStreamReader(System.in));


		DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
		
		BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
		sentence = inFromUser.readLine();

		outToServer.writeBytes(sentence + "\n");

		modifiedSentence = inFromServer.readLine();

		System.out.println("FROM SERVER: " + modifiedSentence);

		clientSocket.close();
	}
}

so again, the question is: is there a way to tell the server to wait until the user inputs the port number before the server gets it?

thanks a lot