Develop Reference

JButton image with different paths

I have added an icon to my JButton and the image is taken from a specific path inside my project files. But the problem is on another machine the path may be slightly different.
For instance my entire image path is home/jon/hello/folder/image.png, but on another machine the path may be /project/folder/william/hello/folder/image.png. Meaning the starting part of the path is different but from the hello part would be the same.
How can I make my path in my button code to be able to match the difference? My button code is below :
btn = new JButton(BUTTON_COLLAPSE_NESTED().toString());
btn.setIcon(newImageIcon("home/jon/hello/folder/image.png"));
btn.setActionCommand(BUTTON_COLLAPSE_NESTED().toString());
btn.addActionListener(btnListener);
btnPnl.add(btn);

This is why you shouldn't use absolute paths. Place the image in the jar, and use relative paths to resources, with the path based on the classpath to your class files.
For instance, if image.png is located in an images folder just off of the class file folder, you'd do something like:
URL url = getClass().getResource("/images/image.png");
BufferedImage img = ImageIO.read(url);
ImageIcon icon = new ImageIcon(img);
or something similar.

How do I add an image to JPanel using imageicon (Java GUI)?

I looked all over the place but I am still stuck on how directory works to find the image to put onto the JPanel. Where is the image supposed to be? I clicked on properties for my image and it shows Location: C:\Users\Joseph\Pictures\Background and the picture's name is random.jpg.
I am trying to add an image to a tab using tabbedPane. Here is what I have so far, and I am not able to do it.
JPanel flPanel = new JPanel();
flPanel.setLayout(new FlowLayout());
ImageIcon image = new ImageIcon(getClass().getResource(""));
// Tried /Users/Joseph/Pictures/Background/random.jpg and doesn't work
JLabel j1 = new JLabel(image);
flPanel.add(j1);
tabbedPane.add("Tab 2", flPanel);
Is the picture supposed to be in the same package file as the project? Or is it supposed to be in the source file to be able to just do "random.jpg"?

If you want the image to be available to your application at runtime, then you should consider making sure that the image is included within your Jar when you application is built.
From the sounds of it, you are using Netbeans, you should copy the image to a directory within your src directory of your project.
You should then be able to use...
BufferedImage bi = ImageIO.read(getClass().getResource("/full/path/to/image/random.jpg"));
ImageIcon image = new ImageIcon(bi);
The path to the image should be the full path (from the context of the src directory) within your project.
That is, if you placed the image in the resources directory within the src directory, then you would use /resources/random.jpg as the path/file name
Take a look at Reading/Loading an Image for more details

getClass().getResource(...) will only get resources inside the classpath.
You can use ImageIO.read(File) like this:
BufferedImage bi = ImageIO.read(new File("C:\\Users\\Joseph\\Pictures\\Background\random.jpg"))
ImageIcon image = new ImageIcon(bi);

Load Java Image inside package from a class in a different package

I have a Java project called MyProject. I have a few different packages (keeping names simple for the purpose of this question), as follows:
src/PackageA
src/PackageA/PackageAa
src/PackageA/PackageAa/PackageAaa
src/PackageB
src/PackageB/PackageBa
src/PackageB/PackageBa/PackageBaa
I have a class
src/PackageA/PackageAa/PackageAaa/MyJavaFile.java
And I have an image
src/PackageB/PackageBa/PackageBaa/MyImage.png
Inside of MyJavaFile.java, I would like to declare an Image oject of MyImage.png
Image img = new Image(....what goes here?...)
How can I do this?

You could either call Class.getResource and specify a path starting with /, or ClassLoader.getResource and not bother with the /:
URL resource = MyJavaFile.class
.getResource("/PackageB/PackageBa/PackageBaa/MyImage.png");
or:
URL resource = MyJavaFile.class.getClassLoader()
.getResource("PackageB/PackageBa/PackageBaa/MyImage.png");
Basically Class.getResource will allow you to specify a resource relative to the class, but I don't think it allows you to use ".." etc for directory navigation.
Of course, if you know of a class in the right package, you can just use:
URL resource = SomeClassInPackageBaa.class.getResource("MyImage.png");
(I'm assuming you can pass a URL to the Image constructor in question. There's also getResourceAsStream on both Class and ClassLoader.)

you can use relative path since the the relative path is project folder.
ImageIcon img = new ImageIcon("src/PackageB/PackageBa/PackageBaa/MyImage.png");

/folderB/folderBa/folderBaa/MyImage.png
The image can stored into a project folder location .eg: /images/MyImage.png
Then try:
Image img = new Image(/images/MyImage.png);
Using a file path is not possible when running a program that's in a jar file, especially if the program is being loaded as an applet or WebStart application then you can use ClassLoader to get image.
use the following code to load the images:
ClassLoader cldr = this.getClass().getClassLoader();
java.net.URL imageURL = cldr.getResource("/PackageB/PackageBa/PackageBaa/MyImage.png");
ImageIcon aceOfDiamonds = new ImageIcon(imageURL);

This IS the best way to handle all images and icons in a JAR App.
Once you've zipped up all of your images and icons into its own JAR file - Configure your build path by adding the images JAR file into your libraries tab so that its now included in your classpath.
Then simply use the following 3x lines of code at the start of your constuctor to access any image you need for anything including a SystemTray image which doesn't accept the simple ImageIcon's as its main icon (weird I know). The 3x lines are:
URL iconUrl = this.getClass().getResource("/image-iconb.png");
Toolkit tk = this.getToolkit();
imageIcon = tk.getImage(iconUrl);
(imageIcon is just a constructor declared Image variable)
Now you can set a window icon as simply as:
setIconImage(imageIcon );
and at the same time use the same variable when setting the System TrayIcon by declaring:
trayIcon = new TrayIcon(imageIcon, "SystemTray Demo", popupMenu);
The above allows you to declare Images or ImageIcons easily and centrally without running the risk of not keeping image resources in the right place. It keeps it nice and tidy, with the JAR containing all your images automatically compiled at run time and distribution of your program.
As a bonus, once the JAR is registered in your classpath - you can keep adding any other images into the same JAR at any time without any fuss too - Everything just works and the added images are instantly available to your app.
Much better in my view.

Use the getResource method to read resources inside the src root. For example, the following code retrieves images from a folder src/images.
// Get current classloader
ClassLoader cl = this.getClass().getClassLoader();
// Create icons
Icon saveIcon = new ImageIcon(cl.getResource("images/save.gif"));
Icon cutIcon = new ImageIcon(cl.getResource("images/cut.gif"));
The example assumes that the following entries exist in the application's JAR file:
images/save.gif
images/cut.gif

Image img = new Image("./src/PackageB/PackageBa/PackageBaa/MyImage.png");
This shall go the path of the image is first inside src (source) then package so the program would access the image this way.

get path of image file that is outside the project in java

I use this code to display image that locates outside the my java project, but I got NullPointerException every time and I can only use images that are inside my project directory. why ?
Icon welcomeImg = new ImageIcon(getClass().getResource("D:/img/welcome.png"));
or
Icon welcomeImg = new ImageIcon(getClass().getResource("D://img/welcome.png"));
JLabel welcomingLb = new JLabel(welcomeImg);

You do not need to use the ClassLoader class to access your file since you are giving its full path.
Try instead :
Icon welcomeImg = new ImageIcon("D:/img/welcome.png");
Source : Javadoc of ImageIcon(String filename)

getResource expects the resource to be on the classpath.
If you want to read from a random file, use a File, or use the ImageIcon constructor that takes a file name.

See: Loading resources using getClass().getResource()
Basically when you use getResource it is expecting the file to be on the Classpath. There is also a constructor for ImageIcon that takes a String filename, so you can pass the path to the Icon file directly.
Check out the JavaDoc for ImageIcon

You can try using a File, like so:
File f = new File("C:\\folder\\stuff\\MyFile.class");

Locating resource in Jar

I am having difficulty creating the image icon. I want to package a jar and have the images available to be displayed in the gui. Both of the following throw null pointer exceptions. The path is a path directly to a package in my Eclipse project that contains the necessary images.
ImageIcon icon = new ImageIcon(this.getClass().getClassLoader().getResource(
"/TicTacToe/src/edu/luc/tictactoe/gui/resources/images/TicTacToeOIcon.png")
.getPath());
and
ImageIcon icon = new ImageIcon(getClass().getResource(
"/TicTacToe/src/edu/luc/tictactoe/gui/resources/images/TicTacToeOIcon.png"));
I can't see to be able to access the appropriate package. Any suggestions?

ImageIcon icon = new ImageIcon(this.getClass().getClassLoader()
.getResourceAsStream("edu/luc/tictactoe/gui/resources/images/TicTacToeOIcon.png");

Try like this
JButton myButton =new JButton(“press me”);
myButton.setIcon(new ImageIcon(image));
EDIT:
Refer to this discussion to know loading the image from executable Jar files