Question

I am using eclipse and I want to add a image onto a label or a logo for my GUI.

I want it to LOOK LIKE THIS!

I uploaded it onto the web because I dont have 10 reputation.

(Names cool program) is the image

 import java.awt.*;
    import javax.swing.*;
    import javax.swing.JFrame;

    public class MainClass extends JFrame{ // super class JFrame

        // Kind of a tutorial for creating GUI's in java
        private JLabel label;
        private JLabel label1;
        private JButton button;
        private JTextField textfeild;
        private ImageIcon image1; // image for my logo

        public MainClass () {
            setLayout (new FlowLayout());

            image1 = new ImageIcon (getClass ().getResource ("logo.gif")); // declares image

            label = new JLabel ("This is the label");
            add (label);

            label1 = new JLabel (image1); // adds image
            add (label1);

            textfeild = new JTextField (15);
            add (textfeild);

            button = new JButton ("Click");
            add (button);

        }

        public static void main(String[] args) {        

            MainClass gui = new MainClass ();


            gui.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE); // creates window
            gui.setSize (300,300);
            gui.setVisible (true);
            gui.pack ();
            gui.setTitle ("Title");

        }

    }

Program compiles but doesn’t run. Gives me

Exception in thread "main" java.lang.NullPointerException
    at javax.swing.ImageIcon.<init>(Unknown Source)
    at JonsCalc.<init>(JonsCalc.java:18)
    at JonsCalc.main(JonsCalc.java:38)

Answer 1

This piece of code getClass().getResource ("logo.gif") means that the image should be loaded from the same location as your class MainClass has. Check that you image is in the same package as MainClass. If you use Eclipse, than put image file in the package in src folder, it will be copied to bin automatically.