My second frame will not open and my first will not close

[Isaac Skelton]

Im having problems with the secong frame, I have put in capital letters a comment next to my problem. I can not get the old frame to disapear and open the new one (I dont know if login.dispose() is even java, it was just a guess).

package isaacskelton.webs.com;

import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;

public class Login {

	public static void main(String[] args) {
		final JFrame login = new JFrame("Login to CheckMate");
		login.setSize(600, 400);
		login.setLocation(375, 150);
		login.setVisible(true);
		login.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		//Login Content
		JLabel welcome_label = new JLabel("  Welcome to CheckMate!");
		welcome_label.setFont(new Font("Lucida Handwriting", Font.BOLD, 36));
		
		JLabel tagline_label = new JLabel("                    Digital Roll System.");
		tagline_label.setFont(new Font("Lucida Handwriting", Font.BOLD, 20));
		
		JLabel username_label = new JLabel("Username:");
		final JTextField txfield_username = new JTextField(35);
		
		JLabel password_label = new JLabel("Password:");
		final JPasswordField passfield_password = new JPasswordField(35);
		
		JLabel blank_space = new JLabel("");
		JButton submit_login = new JButton("Login");
		submit_login.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e){
            	//Strings
        		String username = txfield_username.getText();
        		String password = passfield_password.getText();
        		
        		//Conditional Statements
        		if(username == "user" && password == "pass") {
                                                //THIS IS MY PROBLEM HERE, THE FRAME WILL NOT APPEAR
        			login.dispose();
        			JFrame main_screen = new JFrame("Welcome" + username);
        			main_screen.setForeground(Color.GRAY);
        			main_screen.setSize(1024, 750);
        			main_screen.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        			main_screen.setVisible(true);
        			//HERES THE END OF THE PROBLEM
        		}
        		else {
        			;
        		}
            }
          });
		
		//Panel
		JPanel panel = new JPanel(new GridLayout(8, 0));
		
		//Add to Panel
		panel.add(welcome_label);
		panel.add(tagline_label);
		
		panel.add(username_label);
		panel.add(txfield_username);
		
		panel.add(password_label);
		panel.add(passfield_password);
		
		panel.add(blank_space);
		panel.add(submit_login);
		
		//Add Panel to Frame
		login.add(panel);

	}
}

Thanks in advanced I. Skelton

[Greg Brannon]

Use the equals() method to compare Strings.

if username.equals( "this" )

etc. . .

[Isaac Skelton]

Greg Brannon wrote:Use the equals() method to compare Strings.

if username.equals( "this" )

etc. . .

Thanks you so much, it worked perfect and it was a quick reply to my question.

[Kemal Sokolovic]

What is that empty statement in else doing there?

When comparing strings, make sure you use equals() as suggested, and try to do it this way:

"user".equals(username)

This way you avoid getting a NullPointerException.

Also, try not to name your variables like_this, but likeThis, since it's common in Java.