Image on JButton

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Image;
import javax.imageio.ImageIO;
import javax.swing.Box;
import javax.swing.BoxLayout;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;

public class Test extends JPanel {
public static void main(String[] args) {
    SwingUtilities.invokeLater(new Runnable() {
        public void run() {

private static void constructGUI() {
    JFrame frame = new JFrame("Testy");

    JPanel centerPanel = new JPanel();
    centerPanel.setPreferredSize(new Dimension(100, 400));
    frame.add(centerPanel, BorderLayout.CENTER);

    Test eastPanel = new Test();
    frame.add(eastPanel, BorderLayout.EAST);


public Test() {

    setLayout(new BoxLayout(this, BoxLayout.PAGE_AXIS));
    Dimension d = new Dimension(50,50);

    JButton button1 = new JButton("");

    button1.setIcon(new ImageIcon(this.getClass().getResource("/Pictures/ellipse.png")));

    button1.setMaximumSize(new Dimension(Integer.MAX_VALUE, button1.getMinimumSize().height));

    JButton button2 = new JButton("");

    button2.setIcon(new ImageIcon(this.getClass().getResource("/Pictures/ellipse.png")));

    button2.setMaximumSize(new Dimension(Integer.MAX_VALUE, button2.getMinimumSize().height));

    JButton button3 = new JButton("");

    button3.setIcon(new ImageIcon(this.getClass().getResource("/Pictures/ellipse.png")));

    button3.setMaximumSize(new Dimension(Integer.MAX_VALUE, button3.getMinimumSize().height));




enter image description here

In my program I am trying to put the ellipse picture on top of all my buttons. As you can see in the image I posted, the ellipse.png is in the “Pictures” source folder. However, I am getting a runtime error for some reason that says:

Exception in thread “AWT-EventQueue-0” java.lang.NullPointerException
at javax.swing.ImageIcon.(

I have read many posts but I can’t see a way to solve my problem.

Also, here is a link to the actual ellipse picture:

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I need integrate ProGuard and maven shade plugin.
Can you give me some tips or help me do this?
My environment:
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    String firstName, midddleInitial, lastName;

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public void process() {
    while (!stopped) {
        for (OutputInputPair pair : pairs) {

first when user click stop button, stopped = true so, if user not click button,
always execute processCommandPairs method.

when stop button click

public void stop() {
    Log.d(TAG, "STOP memory leak");
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I have only 1 question, if user does not not click button, occur memory leak in array list is right?

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enter image description here

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Code for setIconImage() won’t work

I am new to Java and NetBeans. However, I have done some C/C++ before.

I wanted to change the icon of my application. So, I had a look on the internet and I found this: Changing the icon of my java application. But when I put in the code (e.g., into the constructor of my JFrame) I always get an error saying “Cannot find symbol: Class Image”. Even when I add “import Image” in the beginning of the file.

What’s wrong here?