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Swing ImageIcon causing error and not making image appear

I am having a problem with my java project. I am trying to make a JFrame with a background image, but when I use javax.swing.ImageIcon to set the icon of the background JLabel it shows an exception error in the console when I run the program and the image doesn't work, only showing a blank JFrame. Here is my code:
#SuppressWarnings("serial")
public class MainUI extends JFrame {
public static void main(String[] args) {
new MainUI().build(); // Calls build method
}
private void build() {
// Builds JFrame
JFrame frame = new JFrame();
JPanel base = new JPanel();
JLabel background = new JLabel();
frame.setVisible(true);
frame.setTitle("Space Age");
frame.setSize(640,480);
frame.setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
frame.setAutoRequestFocus(false);
frame.setCursor(new java.awt.Cursor(java.awt.Cursor.DEFAULT_CURSOR));
frame.setLocationRelativeTo(null);
base.setSize(640,480);
base.setAlignmentX(0.0F);
base.setAlignmentY(0.0F);
base.setBackground(new java.awt.Color(255,255,255));
background.setSize(640,480);
background.setAlignmentX(0.0F);
background.setAlignmentY(0.0F);
background.setIcon(new ImageIcon(getClass().getResource("spaceage.images.starfield.png")));
frame.add(base);
frame.add(background);
}
}
This is what the error message looks like:
Exception in thread "main" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(Unknown Source)
at spaceage.src.MainUI.build(MainUI.java:36)
at spaceage.src.MainUI.main(MainUI.java:15)
Can someone tell me what I did wrong and how to to make the image display properly?
Thanks in advance,
Santiago

I figured out what I did wrong. This:
background.setIcon(new ImageIcon(getClass().getResource("spaceage.images.starfield.png")));
needed to be changed to this:
background.setIcon(new ImageIcon(getClass().getResource("/spaceage/images/starfield.png")));
I got a NullPointerException because I entered the path to my image incorrectly, so getResource() couldn't find the image and returned null.

Also this will help you. You can link it with your requirement.
you can use this-
ImageIcon iid = new ImageIcon("C:\\Users\\ranig\\My\\spaceinvaders\\ball.png");
Note: C:\Users\ranig\My\spaceinvaders\ball.png is the whole path of ball.png image.
instead of this:
ImageIcon iid = new ImageIcon(this.getClass().getResource("ball.png"));

Displaying an image in a JFrame

I am currently learning Java, and I am stuck with something at the moment.
I was looking for a way to add an image to my JFrame.
I found this on the internet:
ImageIcon image = new ImageIcon("path & name & extension");
JLabel imageLabel = new JLabel(image);
And after implementing it to my own code, it looks like this (this is only the relevant part):
class Game1 extends JFrame
{
public static Display f = new Display();
public Game1()
{
Game1.f.setSize(1000, 750);
Game1.f.setResizable(false);
Game1.f.setVisible(true);
Game1.f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Game1.f.setTitle("Online First Person Shooter");
ImageIcon image = new ImageIcon("C:\\Users\\Meneer\\Pictures\\image.png");
JLabel imageLabel = new JLabel(image);
add(imageLabel);
}
}
class Display extends JFrame
{
}
When running this code, it doesn't give me any errors, but it also doesn't show the picture. I saw some questions and people having the same problem, but their code was completely different from mine, they used other ways to display the image.

You don't need to use another JFrame instance inside the Game JFrame:
Calling setVisible(flag) from the constructor is not preferable. Rather initialize your JFrame from outside and put your setVisible(true) inside event dispatch thread to maintain Swing's GUI rendering rules using SwingUtilities.invokeLater(Runnable)
Do not give size hint by setSize(Dimension) of the JFrame. Rather use proper layout with your component, call pack() after adding all of your relevant component to the JFrame.
Try using JScrollPane with JLabel for a better user experience with image larger than the label's size can be.
All of the above description is made in the following example:
class Game1 extends JFrame
{
public Game1()
{
// setSize(1000, 750); <---- do not do it
// setResizable(false); <----- do not do it either, unless any good reason
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("Online First Person Shooter");
ImageIcon image = new ImageIcon("C:\\Users\\Meneer\\Pictures\\image.png");
JLabel label = new JLabel(image);
JScrollPane scrollPane = new JScrollPane(label);
scrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
add(scrollPane, BorderLayout.CENTER);
pack();
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Game1().setVisible(true);
}
});
}
}

do this after creating Jlabel
imageLabel.setBounds(10, 10, 400, 400);
imageLabel.setVisible(true);
also set the layout to JFrame
Game.f.setLayout(new FlowLayout);

You are adding the label to the wrong JFrame. Also, move the setVisible() to the end.
import javax.swing.*;
class Game1 extends JFrame
{
public static Display f = new Display();
public Game1()
{
// ....
Game1.f.add(imageLabel);
Game1.f.setVisible(true);
}
}

Also try to use image from resources, and not from hardcoded path from your PC
You can look in here, where sombody asked similar question about images in Jframe:
How to add an ImageIcon to a JFrame?

Your problem in next you add your JLabel to Game1 but you display another Frame(Display f). Change add(imageLabel); to Game1.f.add(imageLabel);.
Recommendations:
1)according to your problem: Game1 extends JFrame seems that Display is also a frame, use only one frame to display content.
2) use pack() method instead of setSize(1000, 750);
3)call setVisible(true); at the end of construction.
4)use LayoutManager to layout components.

Displaying an image in Java Swing

public class MinesweeperMenu extends MinesweeperPanel{
private JPanel picture = new JPanel();
private JButton play = new JButton("Play");
private JButton highScores = new JButton("High Score and \nStatistics");
private JButton changeMap = new JButton("Create Custom \nor Change Map");
private JButton difficulty = new JButton("Custom or\nChange Difficulty");
private JButton user = new JButton("Change User");
Image img;
public MinesweeperMenu()
{
// Set Layout for the menu
LayoutManager menuLayout = new BoxLayout(menu, BoxLayout.Y_AXIS);
menu.setLayout(menuLayout);
// Set Layout for the window
LayoutManager windowLayout = new BorderLayout();
window.setLayout(windowLayout);
// Add buttons to the panels
menu.add(play);
menu.add(highScores);
menu.add(changeMap);
menu.add(difficulty);
menu.add(user);
// Add picture to the frame
try{
File input = new File("./setup/images/MineMenuPicture.jpg");
img = ImageIO.read(input);
}
catch(IOException ie)
{
System.out.println(ie.getMessage());
}
// Add action listeners
changeMap.addActionListener(new ChangeMapListener());
}
public void paintComponent(Graphics g)
{
// POSITION OF THE PICTURE
int x = 650;
int y = 585;
g.drawImage(img, x, y, null);
}
public void displayFrame()
{
// Display Frame
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setVisible(true);
}
public static void main(String[] args)
{
MinesweeperMenu menu = new MinesweeperMenu();
window.pack();
menu.displayFrame();
window.repaint();
}
}
public class MinesweeperPanel extends JFrame{
public static final Color COLOR_KEY = new Color(220, 110, 0);
// Initialize all the objects
public static JFrame window = new JFrame("Minesweeper++");
public static JPanel menu = new JPanel();
// Close the current window
public static void close()
{
window.setVisible(false);
window.dispose();
}
}
I can't get my image to display in the frame. I've tried everything, but I'm getting the impression it's a mistake that I'm not realizing since I am new to Java Swing. Any help would be greatly appreciated.

You're making things difficult for yourself by having a very confusing program structure, and I suggest that you simplify things a lot.
For one, there's no need for your current MinesweeperMenu class to extend MinesweeperPanel, and for the latter class to extend JFrame. Then you have a static JFrame somewhere else -- that's too many JFrames, and to boot, you're trying to display your image in one JFrame but showing the other one that doesn't have the picture. Your program needs just one JFrame and it should probably be created, stuffed with its contents, packed and displayed in one place, not scattered here and there as you're doing.
You're trying to display the picture in a paintComponent override, but this method will never get called since your class extends JFrame (eventually) and JFrame doesn't have this method. You're using the right method, but the class should be extending JPanel, and you should have an #Override annotation above the paintComponent method block to be sure that you're actually overriding a parent method.
You should get rid of all static everything in this program. The only thing static here should be the main method and perhaps some constants, but that's it.
There are more errors here, and I have too little time to go over all of them. Consider starting from the beginning, starting small, getting small bits to work, and then adding them together.
For instance, first create a very small program that tries to read in an image into an Image object, place it in a ImageIcon, place the ImageIcon into a JLabel, and display the JLabel in a JOptionPane, that simple, just to see if you can read in images OK, for example, something like this:
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
public class TestImages {
// *** your image path will be different *****
private static final String IMG_PATH = "src/images/image01.jpg";
public static void main(String[] args) {
try {
BufferedImage img = ImageIO.read(new File(IMG_PATH));
ImageIcon icon = new ImageIcon(img);
JLabel label = new JLabel(icon);
JOptionPane.showMessageDialog(null, label);
} catch (IOException e) {
e.printStackTrace();
}
}
}
Then when you've done this, see if you can now create a JPanel that shows the same Image in its paintComponent method, and display this JPanel in a JOptionPane.
Then create a JFrame and display the image-holding JPanel in the JFrame.
Through successive iterations you'll be testing concepts, correcting mistakes and building your program.

File input = new File("./setup/images/MineMenuPicture.jpg");
If MineMenuPicture.jpg is an application resource, it should be in a Jar and accessed by URL obtained from Class.getResource(String).

Images not painting/loading right away in Swing Java Desktop Application

When I run my Java Desktop Application created with Netbean's Swing, the JLabel icon images load right away but the background images on my JPanel don't paint to the screen until I wake-up (re-size) the window.
Here is the custom code on my JPanel:
Image image = java.awt.Toolkit.getDefaultToolkit().getImage(getClass().getResource("/images/background.gif"));
javax.swing.JPanel panelBackground = new BackgroundPanel(image);
Is there a better way to call the image? Is there image handling code I should be implementing?
How should I fix it?

Works fine for me. I tested it using the Background Panel. Post your SSCCE if you still have a problem.
import java.awt.*;
import javax.swing.*;
public class BackgroundSSCCE extends JPanel
{
public BackgroundSSCCE()
{
setLayout( new BorderLayout() );
Image duke = java.awt.Toolkit.getDefaultToolkit().getImage(getClass().getResource("dukeWaveRed.gif"));
BackgroundPanel test = new BackgroundPanel(duke, BackgroundPanel.ACTUAL, 1.0f, 0.5f);
add(test);
}
private static void createAndShowUI()
{
JFrame frame = new JFrame("BackgroundSSCCE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( new BackgroundSSCCE() );
frame.setSize(200, 200);
frame.setLocationRelativeTo( null );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}

Got it!
Many thanks to Hovercraft Full Of Eels for the pointer
"What happens if you use ImageIO.read(...) to get your image? Also, are you adding the image-displaying component to the GUI after it has been rendered?"
And to camickr for the code to think on.
I resolved it by using:
Image imgBackground = ImageIO.read(getClass().getResourceAsStream("/images/background.gif"));
Creating and assigning the image to the variable at the beginning of my class instead of in the JPanels custom code section also worked. That is because the image had more time to be created..

How to create rounded JButton in java..?

I want to create rounded JButton in Java...
For that I use rounded image and placed that image on button but I didn't get rounded button..
please any one can tell how to create rounded button in Java like show in below figure..
thanks in advance.....

If you're just going to use an image of a round button, then why not just use a JLabel? That is, simply invoke setIcon(...), passing your BufferedImage instance as an argument.
CODE
public final class RoundedButtonDemo {
private static BufferedImage bi;
public static void main(String[] args){
try {
loadImage();
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run() {
createAndShowGUI();
}
});
} catch (IOException e) {
// handle exception
}
}
private static void loadImage() throws IOException{
bi = ImageIO.read(RoundedButtonDemo.class.getResource("../resources/login.png"));
}
private static void createAndShowGUI(){
final JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JLabel label = new JLabel();
label.setIcon(new ImageIcon(bi));
frame.getContentPane().add(label);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
OUTPUT
Keep in mind that you'll need to either programmatically make the background of your image transparent, or you'll need to use an image editing tool like Paint.NET.

You need to write a "Look and Feel" (a theme for Java Swing). Not for the faint of heart but possible. I suggest to look at an existing theme.
LIQUIDLNF should be a good start.

You can use JavaFX to define "Rich Graphic Components" example (rounded button with gradient): http://poligloci.blogspot.com/2009/07/beauty-and-beast-javafx-12-in-netbeans.html