Read images from external jar file (Sun's Java L&F Graphics repository)

Question

Hi!
I don't know how to read images from an external jar file. Sun has a Java Look and Feel graphics repository that contains a lot of good images that can be used on buttons and so on. This repository is delivered as a jar file, containing only images, and I want to read the image files from that jar file directly without including them inside my application jar file. The application and image jar files will be in the same directory.
I have absolutely no clue how to solve this. Is it necessary to include the images inside my application jar file or is it possible to have them separate as I want.
Would really appreciate some help!
Best regards
Lars

Answer 1

Hi,
There is two ways :
1) Add your jarfile to the classpath.
Use the class loader :
URL url = ClassLoader.getSystemResource("your/package/image.gif");
Image im = (new ImageIcon(url)).getImage();
or
Image im = Toolkit.getDefaultToolkit().getImage(url);2)If you don't want to add the jar to the classpath you can use this (under jdk 1.4):
import java.util.*;
import java.util.jar.*;
import java.awt.*;
import java.io.*;
import java.awt.image.*;
import javax.imageio.*;
public class ImageUtilities {
     public static Image getImage(String jarFileName, String fileName) {
          BufferedImage image = null;
          try {
               JarFile jar = new JarFile(new File(jarFileName), false, JarFile.OPEN_READ);
               JarEntry entry = jar.getJarEntry(fileName);
               BufferedInputStream stream = new BufferedInputStream(jar.getInputStream(entry));
               image = ImageIO.read(stream) ;
          catch (Exception ex) {
               System.out.println(ex);
          return(image);
}I hope this helps,
Denis