Develop Reference

Gif no long animated after replacing with JLabel's setIcon method

I am still very new to Java and programming in general. I am trying to display a GIF using Swing and the following code:
JPanel contentPane;
JLabel imageLabel = new JLabel();
public FrostyCanvas(String imageName) {
try {
setDefaultCloseOperation(EXIT_ON_CLOSE);
contentPane = (JPanel) getContentPane();
contentPane.setLayout(new BorderLayout());
setSize(new Dimension(1600, 900));
setTitle("FrostySpirit v1.1.1 (Beta) - FrostyCanvas");
// add the image label
ImageIcon ii = new ImageIcon(this.getClass().getResource(imageName));
imageLabel.setIcon(ii);
contentPane.add(imageLabel, java.awt.BorderLayout.CENTER);
// display target GIF
this.setLocationRelativeTo(null);
this.setVisible(true);
} catch (Exception exception) {
exception.printStackTrace();
}
}
The method call is the following: (in a different class)
FrostyCanvas FC = new FrostyCanvas("old.gif");
The GIF is animated at this point. I then try to replace the GIF with another one using the following method: (in the same class as ForstyCanvas(String imageName))
public void changeGif(String imageName) throws IOException
{
Icon icon; File file;
file = new File(imageName);
icon = new ImageIcon(ImageIO.read(file));
imageLabel.setIcon(icon);
}
I call the method above in a different class using the following code:
FC.changeGif("D:\\new.gif")
The image is successfully replaced. However, now it only shows the very first frame of new.gif and is no longer animated. How can I make the new GIF move?

The way ImageIO reads the image is creating a static image. The thing to do is to use ImageIcon's loader.
ImageIcon replacement = new ImageIcon(file.toURI().toURL());
That way you are using the same method to construct the image icon as you do with the resource / url.

How to show images in JTable Cell?

I am trying to use JTable for showing my personnel list with each picture dedicated to each person. I want to show these images in a JTable cell. I achieved showing images from directory with custom cell renderer. This cell renderer returns the label which has icon via the method new ImageIcon(). Every time scrolling happens in my JTable, I guess this renderer works and creates new images from the directory. So this makes RAM explode and glitches in the images. I read all of the questions related to this problem, however I could not find an efficient way to solve it. An approach to this problem would be much appreciated.
My renderer looks like:
public class ImageCellRenderer extends DefaultTableCellRenderer{
JLabel lbl=new JLabel();
public Component getTableCellRendererComponent(defaultparameters){
ImageIcon imageIcon=new ImageIcon(getClass().getResource("path to directory"+table.getModel().getValueAt(row,column).toString+".jpg"));
"""
Some code to turn image icon to scaled version
"""
lbl.setIcon(imageIcon)
return lbl;
}
}

Use the same ImageIcon, I guess.
Something like:
// Note: Probably don't use `DefaultTableCellRenderer`,
// unless you are using the `JLabel` part of that.
public class ImageCellRenderer extends DefaultTableCellRenderer {
private final JLabel label = new JLabel();
private final Map<String,ImageIcon> images = new HashMap<>();
public Component getTableCellRendererComponent(defaultparameters) {
ImageIcon imageIcon = images.computeIfAbsent(
value.toString(),
// No need to look value up again. Delete this:
//table.getModel().getValueAt(row,column).toString(),
cell -> {
ImageIcon newImage = new ImageIcon(
getClass().getResource("path to directory"+cell+".jpg")
);
"""
Some code to turn image icon to scaled version
"""
return newIcon;
}
);
lbl.setIcon(imageIcon)
return lbl;
}
}
(Whether you want to share the "cache" (leek) between renderers and cache eviction policy is left as an exercise.)

How to paint an Image that from a JFileChooser?

I want the user to be able to click a button and choose and image which'll be displayed on the screen.
This is the code I wrote. It doesn't seem to work:
uploadBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int retVal = fc.showOpenDialog(EditImage.this);
if(retVal == JFileChooser.APPROVE_OPTION){
File file = fc.getSelectedFile();
try{
Image img = ImageIO.read(file);
if(img==null){
//TODO: THE FILE IS NOT AN IMAGE. ERROR
}
ImageIcon ic = new ImageIcon(img);
JLabel imageLabel = new JLabel(ic);
imagePreview.add(imageLabel);
}
catch(IOException ex){
//TODO: THE FILE COULD NOT BE OPENED.
}
}
}
});
imagePreview is a JPanel that I've got somewhere on the screen.
What am I doing wrong?

agree with other answers here is required to call container.revalidate() and (there is an Image, then to required) container.repaint()
but this logics is wrong, you couldn't, why to add/remove JComponent for showing another Image, there no reason for, you can to switch betweens ImageIcons in JLabel - JLabel.setIcon(file)
and there is another issue, Images can increasing used JVM memory, you have to call Icon/ImageIcon.flush() before is added to JLabel.setIcon(a few times mentioned here)

Is imagePreview already visible when you add the JLabel to it? If so, you can't just add components to a visible container; you have to revalidate it.

call imagePreview.revalidate(); imagePreview.repaint() after imagePreview.add(imageLabel);, that needed if you add components to visible container.

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.

Image won't appear in JLabel

I've created GUI for my application using Netbeans' GUI Builder. I am trying to display a JFrame containing a JLabel with an image, and I can't get the Image to display.
My generated code :
private void initComponents() {
//...
jLabel1 = new JLabel(new ImageIcon(myPicture));
}
And my class code:
public class GUIWindow extends javax.swing.JFrame {
BufferedImage myPicture;
/** Creates new form GUIWindow */
public GUIWindow() throws IOException {
myPicture = ImageIO.read(new File("images/logo.png"));
initComponents();
this.add(jLabel1);
}
}
but I still don't see an image ... (path to the image file is fine) its sth like:
my-project :
/build
/dist
/images/logo.png
/nbproject
/src (here I have all my source files)
/build.xml
/manifest.mf

you can use like this
URL imgSmartURL = this.getClass().getResource("your image path");
jLabel1 = new JLabel(new ImageIcon(imgSmartURL), JLabel.CENTER);

I would do something like this instead.
JLabel dice1 = new JLabel();
ImageIcon one = new ImageIcon("dice/1.png");
//set dice1 position
dice1.setLocation(20, 100);
dice1.setSize(115, 115);
dice1.setIcon(one);
gamepanel.add(dice1);

If you are using netbeans you can directly add an image to a jLabel by setting properties. Right click on the jLabel -> properties -> icon -> (if it's external image) import to project(upload your image) -> ok .
It'l be added into your jLabel.

I'd suggest you copy the image in a seperate folder(images).
Then use Toolkit.getDefaultToolkit().getImage("images/A.png");
I believe there's a similar question

private ImageIcon imageIconPrint =
new ImageIcon(getClass().getResource("/image/print.gif"));
create button and add follwing code:
jbtCanada.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
jlblFlag.setIcon(imageIconCanada);
}
});
this would help i think