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Dynamically Add Image To JLabel [closed]

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I am attempting to dynamically add an image to my JLabel then add the JLabel to my panel. My code is throwing no errors, but the image is never shown.
public JFrameGamePlay(String playername, String playerselected) {
initComponents();
playerimage = "/Users/owner/Downloads/__Pikachu.png";
ImageIcon pimage = new ImageIcon(playerimage);
JLabel lblPlayer = new JLabel(pimage);
pnlPlayer.add(lblPlayer);
pnlPlayer.validate();
pnlPlayer.repaint();
}
public static void main(String args[]) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new JFrameGamePlay().setVisible(true);
}
});
}
EDIT
So from further googling I came up with this syntax
JLabel lblPlayer;
lblPlayer = new JLabel(new ImageIcon(getClass().getClassLoader().getResource("__Image1.png")));
pnlPlayer.add(lblPlayer);
pnlPlayer.validate();
pnlPlayer.repaint();
but when I run the code I get this debug error:
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(ImageIcon.java:217)
This is the GUI layout of how I want my data to appear - it is 1 panel on the left and 1 panel on the right - each with a label dynamically created and populated with an image. But no image is being populated.
EDIT 2
I added a black border around my 2 Panels, and when the JForm is loaded neither panel is being displayed. So it seems that what everyone is telling me that GUI designing in NetBeans is pretty buggy. How can I dynamically in my code behind add the two panels one left and one right with a size of 143, 246?
EDIT 3
Still no mustard and I'm using this syntax:
public JFrameGamePlay() {
initComponents();
JPanel leftpanel = new JPanel();
JPanel rightpanel = new JPanel();
JSplitPane pane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, leftpanel, rightpanel);
JLabel lblPlayer = new JLabel(new ImageIcon("/resources/__Image1.png"));
leftpanel.add(lblPlayer);
leftpanel.validate();
leftpanel.repaint();
}

Use ImageIO.read(File) to read the Image. Like,
File playerimage = new File("/Users/owner/Downloads/__Pikachu.png");
ImageIcon pimage = new ImageIcon(ImageIO.read(playerimage));
JLabel lblPlayer = new JLabel(pimage);
pnlPlayer.add(lblPlayer);

The NullPointerException comes from the getResource("__Image1.png") returning null because it didn't find the file. You should prefix it with the location from the classpath (after all, the ClassLoader loads the file). E.g. if the image is in a res directory in your jar (or in your classpath):
JFrameGamePlay.class.getClassLoader().getResource("/res/__Image1.png")));
Or you can directly give a complete path:
new JLabel(new ImageIcon("/images/thewall.png"));
Example:
public class JFrameGamePlay extends JFrame {
private static final long serialVersionUID = 1L;
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(100, 100, 450, 300);
JPanel contentPane = new JPanel(new BorderLayout());
frame.setContentPane(contentPane);
JLabel label = new JLabel(new ImageIcon("/images/thewall.png"));
contentPane.add(label, BorderLayout.CENTER);
JLabel label1 = new JLabel(new ImageIcon(JFrameGamePlay.class.getResource("/javax/swing/plaf/basic/icons/JavaCup16.png")));
contentPane.add(label1, BorderLayout.NORTH);
frame.setVisible(true);
}
}

My code is throwing no errors, but the image is never added.
Yes, this is unfortunately how ImageIcon works. It doesn't throw exceptions or anything if it's unable to read from the filename or URL you pass to it. The code runs without error but simply shows nothing.
playerimage = "/Users/owner/Downloads/__Pikachu.png";
If you want to read from a file at a fixed location like this, then it won't be helpful to mess with getClassLoader().getResource(). That could be helpful to read an image file that you package with your application, but not to read an image in the user's home directory. Your original new ImageIcon(imageLocation) approach is appropriate for that.
[note: I think it's a good idea to send the filename (or URL) directly to the ImageIcon, as your original code does. Other answers suggest ImageIO.read(), which can be helpful to see where it's going wrong, but you could change it back to ImageIcon(filenameOrUrl) once you get it working. But it's not a big deal.]
I am attempting to dynamically add an image to my JLabel then add the JLabel to my panel.
If by "dynamically" you mean to do this when some event occurs, after the panel is already visible on the screen, then I suggest not doing that.
That is, instead of doing this...
JLabel lblPlayer = new JLabel(pimage);
pnlPlayer.add(lblPlayer);
pnlPlayer.validate();
pnlPlayer.repaint();
...you could add the JLabel to your panel (invisible because no text or image) at the very start, before your panel is shown on screen. Then dynamically add the ImageIcon to the already-extant JLabel. All you need to call is existingLabel.setIcon(...). There would be no need to call validate() or repaint().

swing doesn't show png icons on jbuttons

I have written a simple JFrame in java and added a button.
Then I added a .png icon to the button but it keeps giving me an exception.
(I don't have any problem with .jpg icons and it works well)
Here are my code and the exceptions.
public class Test
{
static JFrame mainFrame;
public static void main(String[] args)
{
mainFrame = new JFrame("a");
mainFrame.setSize(300, 300);
mainFrame.setLocation(50, 50);
JButton btn = new JButton();
ImageIcon icon = new ImageIcon("C:\\a.png");
btn.setIcon(icon);
btn.setSize(100, 100);
btn.setLocation(50, 50);
mainFrame.add(btn);
mainFrame.setVisible(true);
}
}
Exceptions :
sun.awt.image.PNGImageDecoder$PNGException: Broken file
at sun.awt.image.PNGImageDecoder.pngassert(PNGImageDecoder.java:94)
at sun.awt.image.PNGImageDecoder.handleChunk(PNGImageDecoder.java:107)
at sun.awt.image.PNGImageDecoder.getData(PNGImageDecoder.java:726)
at sun.awt.image.PNGImageDecoder.produceImage(PNGImageDecoder.java:252)
at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:269)
at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:205)
at sun.awt.image.ImageFetcher.run(ImageFetcher.java:169)
sun.awt.image.PNGImageDecoder$PNGException: Broken file
at sun.awt.image.PNGImageDecoder.pngassert(PNGImageDecoder.java:94)
at sun.awt.image.PNGImageDecoder.handleChunk(PNGImageDecoder.java:107)
at sun.awt.image.PNGImageDecoder.getData(PNGImageDecoder.java:726)
at sun.awt.image.PNGImageDecoder.produceImage(PNGImageDecoder.java:252)
at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:269)
at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:205)
at sun.awt.image.ImageFetcher.run(ImageFetcher.java:169)

Code is fine, there's problem with your image file

JFrame don't work when adding an Image

I'm having a problem that seems a little bit strange. When I'm adding a new ImageIcon and try to run the program it just gives me a gray screen and no objects are added.
public class Ctester {
public Ctester(){
Frame();
}
public void Frame(){
JFrame fr = new JFrame();
fr.setVisible(true);
fr.setSize(500, 500);
fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fr.setResizable(false);
JPanel p = new JPanel(new GridBagLayout());
ImageIcon icon = new ImageIcon(getClass().getResource("zippo.jpg"));
JLabel l = new JLabel(icon)
JButton bm1 = new JButton("hellu");
p.add(l);
p.add(bm1);
fr.add(p);
}
public static void main(String[]args){
new Ctester();
}
}
But if I remove the line:
ImageIcon icon = new ImageIcon(getClass.getResource("zippo.jpg"));
then it works perfect.
I'm not getting any error messages and i been looking for a while but I could only find that the problem might be something with the gridbaglayout.
How can i solve it or do I have to change layout?
(this is just a simple code based of the original as an example so any solutions that not include having to change layout is highly appreciated)

Most of the code is wrong:
Swing components should be create on the Event Dispatch Thread (EDT).
The frame should be made visible AFTER all the components have been added to the frame.
You are attempting to use a GridBagLayout, but you aren't using any GridBagConstraints when you add the components.
Method names (Frame) should NOT start with an upper case character.
Read the Swing Tutorial for Swing basics.
You can find working examples in:
How to Use GridBagLayout
How to Use Icons
so any solutions that not include having to change layout is highly appreciated
Start with the working examples and make changes for your requirements. If you start with better structured code you will have less problems.

If something draws correctly after a window resize or minimize/maximize that is a sure sign of a race condition because you are not starting your GUI on the event dispatcher thread. Your main problem is you are calling setVisible() way to early, don't call setVisible() until after you have added all components to your top-level container. The other problem is you are not starting your GUI on the event dispatcher thread. Please see the main method below in the fixed code:
public class Ctester {
public Ctester() {
Frame();
}
public void Frame() {
JFrame fr = new JFrame();
fr.setSize(500, 500);
fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
fr.setResizable(false);
JPanel p = new JPanel(new GridBagLayout());
JLabel l = new JLabel("label");
JButton bm1 = new JButton("hellu");
p.add(l);
p.add(bm1);
fr.add(p);
fr.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
new Ctester();
}
});
}
}

Try this code you might want to put that first line of code in a try catch just in case that it doesn't find the image.
URL iconURL = getClass().getResource("/some/package/favicon.png");
// iconURL is null when not found
ImageIcon icon = new ImageIcon(iconURL);
fr.setIconImage(icon.getImage());
Also use a .ico file if you are only using this program on Windows but use a .png if it is going to be multi-platform

Background Image of a window in Java using JFrame

So, I've recently started learning Java, and I am really enjoying it despite the several issues and things that I have not yet understood, it makes me keep going on with it. So, considering that it is my first ever programming language, bear with me on any "noob" mistakes I make.
So, I created a fullscreen window using JFrame:
import java.awt.BorderLayout;
import java.awt.FlowLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
public class Main extends JFrame {
public static void main(String[] args) {
//Window
JFrame mainWindow = new JFrame("Day One");
mainWindow.setExtendedState(JFrame.MAXIMIZED_BOTH);
mainWindow.setUndecorated(true);
mainWindow.setVisible(true);
//End Window
}
}
And then I tried to add a background image to the window by adding this:
mainWindow.setLayout(new BorderLayout());
mainWindow.setContentPane(new JLabel(new ImageIcon("C:\\Users\\Recordings\\Desktop\\Day One\\Images\\Main-Background-Image.png")));
mainWindow.setLayout(new FlowLayout());
I found this code here but it isn't working at all. In this website there are two different ways of making it but I have tried both of them and none works.
I have also searched here, in stackoverflow, for similar questions, but all of them were either unanswered or answered with the same example as mine.
I really hope I have been clear enough, thank you very much for your time
EDIT:
As suggested, I have separated the long single statement:
mainWindow.setContentPane(new JLabel(new ImageIcon("C:\\Users\\Recordings\\Desktop\\Day One\\Images\\Main-Background-Image.png")));
Into three more easier debugged statements:
ImageIcon image = new ImageIcon("C:\\Users\\Recordings\\Desktop\\Day One\\Images\\Main-Background-Image.png");
JLabel label = new JLabel(image);
mainWindow.setContentPane(label);

Just a few tips
Its usually best to put a panfel within a frame and then add components to that. Makes for good containment when swing classes get a bit bigger.
Its better to create a resource folder for your projects. Create one in the source of your project e.g. where the src and bin folders are located for your project and name it "resources".
When creating and image icon its good practice to surround with a try catch so you can give appropriate errors and locate easily, or even handle the error at runtime.
With all that being said, here is your code with a little extra. It creates a panel to hold the jlabel(image) and it adds that panel to the frame. It creates an image icon with a quick method, all you have to do is pass in the file name. This method assumes you have created the folder in your project directory called resources and placed your image in there.
public static void main(String[] args) {
//Window
JFrame mainWindow = new JFrame("Day One");
mainWindow.setExtendedState(JFrame.MAXIMIZED_BOTH);
mainWindow.setUndecorated(true);
//Create image
JLabel imageHolder = new JLabel();
imageHolder.setIcon(makeImageIcon("example.png"));
//Add image to panel, add panel to frame
JPanel panel = new JPanel();
panel.add(imageHolder);
mainWindow.add(panel);
mainWindow.setVisible(true);
}
//Creates imageicont from filename
public static ImageIcon makeImageIcon(String filename) {
BufferedImage myPicture = null;
try {
myPicture = ImageIO.read(new File("resources/" + filename));
} catch (IOException e) {
e.printStackTrace();
}
return new ImageIcon(myPicture);
}
Hope this helps

How to put an image on a JButton?

I am writing a program that requires I have a button with an image over top of it, however, so far, I have not been able to get it to work. I have checked several other posts on this site, including How do I add an image to a JButton.
My Code:
public class Tester extends JFrame
{
public Tester()
{
JPanel panel = new JPanel();
getContentPane().add(panel);
panel.setLayout(null);
setTitle("Image Test");
setSize(300,300);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
JButton button = new JButton();
try
{
Image img = ImageIO.read(getClass().getResource("Images\\BBishopB.gif"));
button.setIcon(new ImageIcon(img));
}
catch (IOException ex) {}
button.setBounds(100,100,100,100);
panel.add(button);
}
public static void main(String[] args)
{
Tester test = new Tester();
test.setVisible(true);
}
}
When this code runs, an error results: Exception in thread "main" java.lang.IllegalArgumentException: input == null! This error occurs at the line:
Image img = ImageIO.read(getClass().getResource("Images\\BBishopB.gif"));
I don't think that this error is due to the file not being found by java code, as my Images folder is in the src folder (I am using Eclipse) as recommended by the above link.
Does anyone have any ideas to what the problem may be?
Thanks.

While using Eclipse, you don't keep your images into src folder instead you create a Source Folder for this purpose. Please refer to this link regarding how to add images to resource folder in Eclipse.

Use this to create the button.
JButton button = new JButton(new ImageIcon(getClass().getClassLoader()
.getResource("Images/BBishopB.gif")));
And what you are doing is setting the Image as the icon. This doesn't work because the setIcon() method requires objects which implement the Icon interface. Hope this helps.

Try putting a foward slash before the package name in getResource() like so:
Image img = ImageIO.read(getClass().getResource("/Images/BBishopB.gif"));

You can just find the image directly:
JButton jb = new JButton(new ImageIcon("pic.png")); //pic is in project root folder
//Tip: After placing the image in project folder, refresh the project in Eclipse.
OR if the image will be in a JAR, I usually create a function to do the retrieval for me so that I can re-use it.
public static ImageIcon retrieveIcon(String path){
java.net.URL imgUrl = 'classpackage'.'classname'.class.getResource(path);
ImageIcon icon = new ImageIcon(imgUrl);
return icon;
}
Then I'll do,
JButton jb = new JButton(retrieveIcon("/pic.png"));

Image img = ImageIO.read(getClass().getResource("Images\\BBishopB.gif"));
This line tries to do too much all at one time which makes it difficult to track down an error when you get one. I suggest splitting it up:
URL imgURL = getClass().getResource("Images\\BBishopB.gif");
Image img = ImageIO.read(imgURL);
Now you can use the Eclipse debugger to check the return value of imgURL, which is the most likely candidate for the NPE. Even though this doesn't tell you why you get an error message, it narrows down the problem considerably.