www.jugpadova.it: Accessing a resource within a .jar

Accessing a resource within a .jar

Emanuele Gesuato — Sun, 05 Feb 2006 19:08:00 -0600

Sometimes it is useful to distribute an application in a jar file through Java Web Start or any other way. So, you could have to read some resource (images or properties file) from inside a jar. How can you do it ? It’s very simple, here’s an example to retrieve an image:

ImageIcon image = (new ImageIcon(getClass().getResource("yourpackage/mypackage/image.gif")));

In general, you can retrieve an InputStream in the following way:

InputStream is = this.getClass().getClassLoader() .getResourceAsStream("yourpackage/mypackage/myfile.xml");

It will run inside or outside the jar. Enjoy !

"Accessing a resource within a .jar" by Verner

Thu, 30 Dec 2010 16:14:17 -0600

Look here!

ImageIcon icon = new ImageIcon(ClassLoader.getSystemResource(“/.png”));

URl url = ClassLoader.getSystemResource(String sourceTarget);

MyWebSite www.vanillaworld.ru

"Accessing a resource within a .jar" by mirli

Tue, 09 Nov 2010 07:00:19 -0600

bravissimo, worked as advertized!

"Accessing a resource within a .jar" by web designing india

Mon, 17 May 2010 02:23:23 -0500

To perform basic tasks with JAR files, we can use the Java Archive Tool Because the Java Archive tool is invoked by using the jar command, for convenience we’ll call it the “Jar tool”.

"Accessing a resource within a .jar" by Web Design London

Wed, 21 Apr 2010 23:55:50 -0500

Hi Emanuele…!!!!!!

I think the given idea by you is very interesting… This all sounds super cool because this is the thing for which I was been looking… Thanks for me such an useful information.. great stuff..!!! Keep the good work.. Hope to see your more and more post so on.

"Accessing a resource within a .jar" by Web Design London

Tue, 23 Mar 2010 05:53:32 -0500

Thanks for providing such useful information. I really appreciate your professional approach.

"Accessing a resource within a .jar" by yosef

Thu, 16 Jul 2009 15:12:22 -0500

for key store

http://www.delphifaq.com/faq/f5003.shtml

simple and works

"Accessing a resource within a .jar" by pant.uday@gmail.com

Fri, 04 Jul 2008 23:55:15 -0500

Thanks for the help. Had been looking for this.

"Accessing a resource within a .jar" by Lucio Benfante

Mon, 15 Oct 2007 08:33:11 -0500

I tried the following code, and it works:

package provaimage;

import java.awt.Image;
import java.awt.Toolkit;
import java.net.URL;

public class Main {

    public static void main(String[] args) {
        URL imgURL = Main.class.getResource("images/image.gif");
        Image image = Toolkit.getDefaultToolkit().getImage(imgURL);
        System.out.println(image);
    }
}

Check that imgURL is not null. I think it could be a classloading problem. Try also with the “long” form:

getClass().getClassLoader().getResource(...

"Accessing a resource within a .jar" by Rui Pereira

Wed, 10 Oct 2007 19:21:39 -0500

Hi there. This all sounds super cool, but I can’t get it work.

I got a JAR file with a default class with a main method to be called.

so the inside of the JAR looks like so :

com/me/stuff/Bling.class images/image.gif META-INF/MANIFEST.MF

All works except for the image bit !

in my Bling class I got :

java.net.URL imgURL = getClass().getResource(“images/image.gif”); image = Toolkit.getDefaultToolkit().getImage(imgURL);

the exception I get when I run my dudle.jar file ( java -jar dudle.jar ) is :

Uncaught error fetching image: java.lang.NullPointerException at sun.awt.image.URLImageSource.getConnection(URLImageSource.java:97) at sun.awt.image.URLImageSource.getDecoder(URLImageSource.java:107) at sun.awt.image.InputStreamImageSource.doFetch(InputStreamImageSource.java:240) at sun.awt.image.ImageFetcher.fetchloop(ImageFetcher.java:172) at sun.awt.image.ImageFetcher.run(ImageFetcher.java:136)

any thoughs ? Thx Rp

"Accessing a resource within a .jar" by Lucio Benfante

Wed, 15 Feb 2006 07:10:05 -0600

“my jug”, it’s not my sentence: Emanuele wrote the original post.

What is not clear or unusual in distributing a Java application in a Jar or through the Java Web Start?

Some links:

http://java.sun.com/products/javawebstart/
http://mindprod.com/jgloss/javawebstart.html

"Accessing a resource within a .jar" by my jug

Tue, 14 Feb 2006 17:59:27 -0600

Sorry fante,

I’m not a trolling , simply I don’t understand your sentence “Sometimes it is useful to distribute an application in a jar file through Java Web Start or any other way” and the explanation with your code.

.. but it’s not important , it’s only curiosity …

Yes, of sure, the next time I don’t back in jugpadova.it

"Accessing a resource within a .jar" by Lucio Benfante

Tue, 14 Feb 2006 07:00:49 -0600

No, with that code you can read a “file” from everywhere, without worrying about the real path or the storage of the “file” (resource), that can even be in a jar or elsewhere in the net, or in a database. It delegates the loading to the classloader, so using the same machanism used for loading the classes in the JVM.

“my jug”, about the other questions…are them on topic? I think you are just trolling. If you are really interested, we have also a mailing-list…but…no stupid questions, please.

"Accessing a resource within a .jar" by my jug

Sat, 11 Feb 2006 22:41:19 -0600

boh , I can’t understand , however It’s not so important!

Mah , maybe simply ,with that code you can read a file into jar file.

but ….

What’s means distribuite an application ?? Where is RMI ?? What’s Java Web Start ??

"Accessing a resource within a .jar" by Dario Santamaria

Mon, 06 Feb 2006 17:36:56 -0600

The ”.jar” into code or in your explanation must be in your classpath. So no name of the ”.jar” is required inside the code. You can include your jar in your classpath using:

java -cp .:<myjarfile>.jar myapplication

"Accessing a resource within a .jar" by my jug

Mon, 06 Feb 2006 11:44:04 -0600

I think , it’s not complete demonstrative. Where is the code, and the ”.jar” into code or in your explanation??

"Accessing a resource within a .jar" by Lucio Benfante

Mon, 06 Feb 2006 07:56:25 -0600

...or briefly:

InputStream is = 
    this.getClass()
    .getResourceAsStream(
        "yourpackage/mypackage/myfile.xml");