Reading images from a JAR file on build path

[Jack Bernstein]

I have a jar file of a bunch of images. I'd like to be able to read an image from the file. I know how to do this if I just put the jar into my project, but how do you do this when the jar is included as a library on your build path? It doesn't seem to work the same.

Below is a test program that works if the jar is included in my project, but does not work when the jar is included in the build path.

import java.util.*;
import java.util.jar.*;
import java.util.zip.*;
import java.io.*;

public class JarReader{
	
	final String JAR_NAME = "images.jar";
	
	public static void main(String[] args) throws IOException{
		new JarReader();
	}

	public JarReader() throws IOException{
		File file = new File(JAR_NAME);
		if(!file.exists()){
			System.out.println("Unable to locate jar file.");
			System.exit(0);
		}

		try{
			JarFile jarfile = new JarFile(JAR_NAME);
			Enumeration em = jarfile.entries();
			for (Enumeration em1 = jarfile.entries(); em1.hasMoreElements();) {
				System.out.println(em1.nextElement());
			}
		}
		catch(ZipException ze){
			System.out.println(ze.getMessage());
		}
	}
}

Thanks in advance for any help!

[Rob Spoor]

Check out how Class.getResource and ClassLoader.getResource (and their helper methods getResourceAsStream) work.