JavaFx 2.0 FXML project How to access variables and project structure - javafx

Question

I am making an IRC client in a javafx fxml project.
I am having difficulties understanding the structure of the project. I get the MVC pattern however i don't know where i have to position the main code part of the client(object initialisation and communication start).
I want to be able to update a textarea with a String from a serverConnection object when the server sends a message.
So where do i position the code and how do i notify my controller that it has to update its text passing the String simultaneously?
This is the application class:
package jircclient;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.util.concurrent.*;
public class JircClient extends Application
{
#Override
public void start(Stage stage) throws Exception
{
Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
Scene scene = new Scene(root);
stage.setTitle("jircClient");
stage.setScene(scene);
stage.show();
System.out.println("Stage SET!");
//This is where i thought that i could write the main part of the program
//but the stage will not load unless the start method finishes
//Creating a serverConnetion is not a problem since it's only an object
//but starting the communication does not let the method we are in to exit
//since it sticks in a while loop forever until i probably cancel it using a
//button (not implemented yet)
//serverConnection server1 = new serverConnection();
//server1.startCommunication();
}
public static void main(String[] args) throws Exception
{
//In this method i cannot go further unless i close the stage-window
//The purpose of it is to launch the start method
Application.launch(args);
}
}
This is the controller class:
package jircclient;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.TextArea;
public class FXMLDocumentController implements Initializable
{
#FXML
private TextArea txt;
#FXML
private void handleButtonAction(ActionEvent event)
{
//In here i will be handling events, however i will need to have
//access to serverConnection objects
System.out.println("You clicked me!");
}
#Override
public void initialize(URL url, ResourceBundle rb)
{
}
}
This is the serverConnection class:
package jircclient;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.ArrayList;
public class serverConnection
{
//VARIABLES
private clientInfo client;
private String server_to_connect = "someserver";
private String channel_to_connect = "#somechannel";
private String serv_resp;
private int port = 6667;
private Socket socket;
private BufferedWriter writer;
private BufferedReader reader;
private ArrayList<channel> channels;
//DEFAULT CONSTRUCTOR
public serverConnection() {client = new clientInfo("test1", "test1", "test1");}
//FULL CONSTRUCTOR
public serverConnection(String server_to_connect, int port, String channel_to_connect) throws IOException
{
client = new clientInfo("test1", "test1", "test1");
this.server_to_connect = server_to_connect;
this.port = port;
this.channel_to_connect = server_to_connect;
try
{
//Creating socket connection
this.socket = new Socket(this.server_to_connect,port);
//Socket output writer
writer = new BufferedWriter(
new OutputStreamWriter(socket.getOutputStream()));
//Socket input writer
reader = new BufferedReader(
new InputStreamReader(socket.getInputStream()));
serv_resp = null;
System.out.println("Connection established.");
}
catch(UnknownHostException exc)
{
System.out.println("ERROR: "+ exc.toString());
}
catch(IOException exc)
{
System.out.println("ERROR: "+ exc.toString());
}
finally
{
System.out.println("Closing connection.");
socket.close();
}
}
//server response getter
public String getServerResponse()
{
return serv_resp;
}
//Introduction to server and listen
public void startCommunication() throws IOException
{
this.socket = new Socket(this.server_to_connect,port);
writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
serv_resp = null;
writer.write("NICK " + client.getClientNickname() + "\r\n");
writer.write("USER " + client.getClientLogin() + " 0 * : " +
client.getClientRealName() + "\r\n");
while ((serv_resp = reader.readLine()) != null)
{
System.out.println(serv_resp);
//FXMLDocumentController.txt.setText(serv_resp);
if (serv_resp.indexOf("004") >= 0)
{
break;
}
else if (serv_resp.indexOf("433") >= 0)
{
System.out.println("Nickname is already in use.");
return;
}
}
//Get channel list
writer.write("LIST \r\n");
writer.flush();
//Join desired client
writer.write("JOIN " + channel_to_connect + "\r\n");
writer.flush();
//keep listening
while ((serv_resp = reader.readLine()) != null)
{
//FXMLDocumentController.txt.setText(serv_resp);
if (serv_resp.startsWith("PING "))
{
this.pingPong();
} else
{
System.out.println(serv_resp);
}
}
}
//Ping respond
public void pingPong() throws IOException
{
writer.write("PONG " + serv_resp.substring(5) + "\r\n");
writer.flush();
}
}
I believe there is no need to add the fxml document since it's big and there is no need.
I also have to state that oracle tutorials were not helpful as they only use the event handling in the controller and they don't implement any other logic.

Answer 1

Here is one possible way to do this:
Give your ServerConnection class a callback to call when it receives a message:
public class ServerConnection {
private Consumer<String> messageCallback ;
public void setMessageCallback(Consumer<String> messageCallback) {
this.messageCallback = mesasgeCallback ;
}
// other fields and methods as before...
public void startCommunication() throws IOException {
// code as before ...
while ((servResp = reader.readLine()) !=null) {
if (messageCallback != null) {
messageCallback.accept(servResp);
}
// etc....
}
// etc
}
}
Now instantiate your ServerConnection class from the controller and pass it a callback:
public class FXMLDocumentController {
ServerConnection serverConnection ;
// ...
public void initialize() {
serverConnection = new ServerConnection();
serverConnection.setMessageCallback(message ->
Platform.runLater(() -> txt.appendText(message+"\n")));
Thread serverThread = new Thread(() -> serverConnection.startListening());
serverThread.setDaemon(true); // thread will not stop application from exiting
serverThread.start();
}
// ...
}