[SOLVED] Thread in GUI Problem

[terox13]

Hi, I have just recently been teaching myself networking and threads in java and I have encountered a problem. I'm trying to make a server - client type chat room and I'm having trouble with a thread in the client code.
Client Code:

//ChitChatClient

import java.io.*;
import java.net.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class ChitChatClient extends JFrame implements Runnable, ActionListener {
	
//	Declares input/output variables	
	static Socket clientSocket = null;  
	static BufferedReader inFromServer = null;
        static DataOutputStream outToServer = null;
	static String input = "", output = "", strPort = "", username = "", numIp = "";
	static int numPort = 0;
	
//	Declares the gui objects
	static JTextArea inputBox, displayBox, userList;
	static JButton send, connect;
	static JTextField ip, port, txtUsername;
	JLabel lblIp, lblPort, lblUsername;

	public ChitChatClient() {
		super("ChitChatClient 2.0");
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		setLayout(null);
		//frame.getContentPane().setBackground(Color.blue);
		setBounds(400, 100, 600, 600);
		setResizable(false);
		
//		Make the inputBox
		inputBox = new JTextArea();
		inputBox.setLineWrap(true);
		inputBox.setBorder(BorderFactory.createEmptyBorder(4, 4, 4, 4));
		JScrollPane inputScroll = new JScrollPane(inputBox);
		inputScroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
		inputScroll.setBounds(20, 450, 440, 100);

//		Makes the displayBox
		displayBox = new JTextArea("");
		displayBox.setBounds(20, 50, 350, 375);
		displayBox.setLineWrap(true);
		displayBox.setEditable(false);
		JScrollPane displayScroll = new JScrollPane(displayBox);
		displayScroll.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
		displayScroll.setBounds(20, 50, 350, 375);
		
//		Makes the button send
		send = new JButton("Send");
		send.setEnabled(false);
		send.setBounds(480, 490, 100, 25);
		send.addActionListener(this);
		
//		Makes the connect button
		connect = new JButton("Connect");
		connect.setBounds(20, 10, 100, 25);
		connect.addActionListener(this);
		
//		Makes lblIp label
		lblIp = new JLabel("Ip address:");
		lblIp.setBounds(130, 10, 75, 25);
		
//		Makes the lblPort label
		lblPort = new JLabel("Port:");
		lblPort.setBounds(310, 10, 50, 25);
		
//		Makes the lblUsername label
		lblUsername = new JLabel("Username:");
		lblUsername.setBounds(400, 10, 75,25);
		
//		Makes the ip JtextField
		ip = new JTextField();
		ip.setBounds(200, 15, 95, 20);
		
//		Makes the port JTextField
		port = new JTextField();
		port.setBounds(345, 15, 40, 20);
		
//		Makes the txtUsername JTextField
		txtUsername = new JTextField();
		txtUsername.setBounds(470, 15, 100, 20);
		
//		Add objects to frame
		add(inputScroll);
		add(displayScroll);
		add(send);
		add(connect);
		add(lblIp);
		add(lblPort);
		add(ip);
		add(port);
		add(lblUsername);
		add(txtUsername);
		
		repaint();
	}
	
	public void actionPerformed(ActionEvent e) { 
		if(e.getSource() == send) {
			try {
				output = inputBox.getText();
				outToServer.writeBytes(username + ": " + output + "\n");
				inputBox.setText("");
			}
			catch(IOException er) {}
		}
		else if(e.getSource() == connect) {
//			Disable connection controls		
			connect.setEnabled(false);
			ip.setEnabled(false);
			port.setEnabled(false);
			txtUsername.setEnabled(false);
				
//		Assign connection variables
			numIp = ip.getText();
			strPort = port.getText();
			numPort = Integer.parseInt(strPort);
			username = txtUsername.getText();
			
//		Creates socket to connect to the server
			try {
				displayBox.append("\nConnecting to server...");
				clientSocket = new Socket(numIp, numPort);
			}
			catch(UnknownHostException er) {
				displayBox.append("\nCan't connect to server.");
//				Enable connection controls		
				connect.setEnabled(true);
				ip.setEnabled(true);
				port.setEnabled(true);
				txtUsername.setEnabled(true);			}
			catch(IOException er) {
				displayBox.append("\nCan't connect to server.");
//				Enable connection controls		
				connect.setEnabled(true);
				ip.setEnabled(true);
				port.setEnabled(true);
				txtUsername.setEnabled(true);
			}
//			Creates an input and output streams	
			try {
//				Creates input from the server	
				inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));	
//				Creates output from the server
				outToServer = new DataOutputStream(clientSocket.getOutputStream());
			}
			catch (IOException er) {
					System.out.println(er);
			}

			[COLOR="Blue"](new Thread(new ChitChatClient())).start();[/COLOR]
		}
    }
	
	public static void main(String args[]) throws Exception {
		JFrame frame = new ChitChatClient();
		frame.setVisible(true);

		displayBox.append("Welcome to ChitChatClient Version 2.0");
		
//		Reads the ip text file
		File file = new File("ClientConfig.txt");
		if (file.exists()) {
			// Create a BufferedReader from the file
			BufferedReader inFile = new BufferedReader(new java.io.FileReader(file));
//			Reads the ip
			numIp = inFile.readLine();
			strPort = inFile.readLine();
			username = inFile.readLine();
			
//			 Close the buffered reader input stream attached to the file
			inFile.close();
			
//			Put the variables in the JTextFields
			ip.setText(numIp);
			port.setText(strPort);
			txtUsername.setText(username);
		}
			
	}
	
	public void run() {
		try {
			displayBox.append("\nServer Connected");
			send.setEnabled(true);
			outToServer.writeBytes("User '" + username + "' has joined.\n");
			while(true) {
				input = inFromServer.readLine();
				displayBox.append("\n" + input);
				Toolkit.getDefaultToolkit().beep();
			}
		}
		catch(IOException er) {
			System.out.println(er);
		}
		finally {
			try {
				clientSocket.close ();
				inFromServer.close();
				outToServer.close();
			} 
			catch (IOException ex) {
				ex.printStackTrace ();
			}
		}	
	}
}

The GUI is a JFrame and is made in the constructor method. What I want to happen is when the user clicks the connect JButton, they connect to the server. I'm assuming I need a thread to handle everything coming in from the server so the user can interact with the GUI at the same time. I start the thread in the actionPerformed method (highlighted in blue). The text "Connecting to server..." shows up but when it gets to the thread it just stops and doesn't implement any of the code in the run() method. I had this program working without the GUI and is basically the same code. The only thing different that I can think of is I started the thread from the main method and not the actionPerformed method. Any help would be greatly appreciated.

[danielstoner]

Don't do anything time consuming on the GUI thread. Start a new thread for connection. Don't update the GUI from other threads but the GUI thread. Use invokeLater()

[terox13]

I got it to work, thank you. I just made a new class that extended thread and called that.

[gogoc]

you can also use "Display.getCurrent().asyncExec(runnable)" to get ur thing done