NullPointerException « JPanel « Java Swing Q&A

  1. Java Swing Q&A
  2. JPanel
  3. NullPointerException




1. Problems using Graphics with Panels in the Java Swing Library    stackoverflow.com

Hey everyone, I am trying to run the following program, but am getting a NullPointerException. I am new to the Java swing library so I could be doing something very dumb. ...

2. NullPointerException using Graphics2D in custom JPanel    stackoverflow.com

I'm extending JPanel to make a custom drawing panel, but am getting a NullPointerException and can't work out why. I've removed code until it's pretty bare, but the error is still ...

3. Can't Access JPanel's Public method/variable, and can't access from Jpanel other public method/variable    stackoverflow.com

package client;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.ImageIcon;
import javax.swing.JPanel;
import javax.swing.JTextArea;

public class YootPanel extends JPanel
{

    private ImageIcon bgIcon;
    public JTextArea textBox;
    public ClientUI clientUI;
  ...

4. JFrame.getContentPane(Jpanel) null pointer exception    coderanch.com

Can anyone explain to me why this code throws a null pointer exception at openFrame.setContentPane(openPanel); [code} import javax.swing.*; import java.awt.event.*; public class Main { JFrame openFrame; JPanel openPanel; public static void main(String[] args) { Main main = new Main(); main.Go(); } public void Go() { openPanel = new JPanel(); openFrame.add(openPanel); openFrame = new JFrame("MysteryQuest (tm)"); openFrame.setSize(400,600); openFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); JMenuBar menuBar = new ...

5. JPanel NullPointerException    java-forums.org

6. "AWT-EventQueue-0" java.lang.NullPointerException Error With Jpanel    forums.oracle.com

I scrolled down past your thousand lines of code, expecting to find the stack trace where the important information about the error is to be found. But it wasn't there. So my idea would be for you to actually look at the stack trace that came out with that error message. Why do you think the JVM prints it, anyway? It ...