Thread: Boolean Value Not Changing

Im writing a simple UDP Server, UDP Client program. The client sends a packet to the server containing, "login:username:password". The server splits the string up, delimited by colons, and checks to see if the username and password are valid. If they are, it responds with "Valid", if not, it responds with "Invalid". In the client program, there is a while that will continue to ask the user for username and password until "Valid" is received from the server. However, I have a boolean in the client named success. It is initialized to false, and when the server replies with "Valid", success should be changed to true. For some reason, I cannot get success to change to true on a "Valid" response form the server. Any ideas?

Client:

class UDPClient 
{ 
    public static void main(String args[]) throws Exception 
    { 
		String serverIP;
		String username;
		String password;
		String out;
		boolean success = false;
 
		System.out.println("\nProgrammer: Lucas Byerley");	
 
		//New BufferedReader object to read input from user
		BufferedReader inFromUser = 
		new BufferedReader(new InputStreamReader(System.in));
 
		//get server IP from client
		System.out.print("\nEnter Server IP: ");
		serverIP = inFromUser.readLine();
 
		//establish the socket
		DatagramSocket clientSocket = new DatagramSocket(); 
 
		//connect to server
		InetAddress IPAddress = InetAddress.getByName(serverIP); 
 
		//create the send and receive packets
		byte[] sendData = new byte[1024]; 
		byte[] receiveData = new byte[1024];
 
		//Ask for username and password until the server
		//responds with "Success"
		while(!(success))
		{
		//Get username from user
		System.out.print("Username: ");
        username = inFromUser.readLine(); 
		//Get password from user
		System.out.print("Password: ");
		password = inFromUser.readLine();
		//combine username and password into 1 string, colon delimted
		out = "login:" + username + ":" + password + ":";
 
		//attach the login information to send packet
		sendData = out.getBytes();
 
		//New DatagramPacket object, send packet
		DatagramPacket sendPacket =
		new DatagramPacket(sendData, sendData.length, IPAddress, 9876);
 
		//Send the packet
		clientSocket.send(sendPacket);
 
		//New DatagramPacket object, recieve packet
		DatagramPacket receivePacket =
		new DatagramPacket(receiveData, receiveData.length);
 
		//receive the packet
		clientSocket.receive(receivePacket);
 
		//Display response
		String response =
		new String(receivePacket.getData());
 
		System.out.println("FROM SERVER: " + response);
 
		if(response.equals("Valid"))
			success = true;
		System.out.println(success);
 
		}
		//close the socket
		clientSocket.close();
		}}

Server:

class UDPServer 
{ 
  public static void main(String args[]) throws Exception 
    { 
		String user1 = "ALICE";
		String user2 = "BOB";
		String user3 = "TED";
		String password = "123";
		String answer;
 
		System.out.println("\nProgrammer: Lucas Byerley");
 
		//establish the socket
		DatagramSocket serverSocket = new DatagramSocket(9876); 
 
		//initialize the send and receive packets
		byte[] receiveData = new byte[1024]; 
		byte[] sendData  = new byte[1024]; 
 
		while(true) 
        { 
 
			//DatagramPacket object, the packet received
			DatagramPacket receivePacket = 
            new DatagramPacket(receiveData, receiveData.length); 
			serverSocket.receive(receivePacket); 
 
			//recieve the login info
			String sentence = new String(receivePacket.getData()); 
			//receive clients IP address
			InetAddress IPAddress = receivePacket.getAddress(); 
			//receive clients port number
			int port = receivePacket.getPort(); 
 
			//split the string up, colon delimeted. token[0] should equal "login",
			//token[1] should be clients username, token[2] clients password
			String[] tokens = sentence.split(":");
 
			//look at first token of string to see if user is logging
			//in or needs a list
			if(tokens[0].equals("login"))
			{
				//check for correct username and password
				if((tokens[1].toUpperCase().equals(user1) || 
					tokens[1].toUpperCase().equals(user2) ||
					tokens[1].toUpperCase().equals(user3)) && (tokens[2].equals(password)))
					{
						answer = "Valid\n";
						//compile and send the packet
						sendData = answer.getBytes();
						DatagramPacket sendPacket = 
						 new DatagramPacket(sendData, sendData.length, IPAddress, port);
						serverSocket.send(sendPacket);
					}
					else
					{
						answer = "Invalid\n";
						//compile and send the packet
						sendData = answer.getBytes();
						DatagramPacket sendPacket = 
						 new DatagramPacket(sendData, sendData.length, IPAddress, port);
						serverSocket.send(sendPacket);
					}
			}
			else if(tokens[0].equals("list"))
			{
				answer = "Here is your list.";
 
				//compile and send the packet
				sendData = answer.getBytes();
				DatagramPacket sendPacket = 
				 new DatagramPacket(sendData, sendData.length, IPAddress, port);
				serverSocket.send(sendPacket);
 
			}
}}}

Originally Posted by bosox960

Fixed! Apparently using response.startsWith() instead of response.equals() fixes the problem.

Congratulations on solving that!