CODEWITHSUNDEEP
java
Fysh
Fysh

Reputation: 153

Load images from a jar file

I have an application that works perfectly from the Netbeans IDE, but when run from the jar file in the dist directory does not load the necessary images.

I have spent 1 1/2 days reading this and other forums, trying to find an answer, but I can't get the jar images to work.

Here he is an extract from my code:

String str = t.getText() + "100.gif";
Image img = null;

if (t != HIDDEN)
{
    ClassLoader cldr = Terrain.class.getClassLoader();
    URL url = cldr.getResource("fantasyhexwar/Images/" + str);

    if (url == null)
        JOptionPane.showMessageDialog(null, "no good");

    img = ImageIO.read(url);
    t.setImage(img);
}

I have tried many combinations of relative path, including "images/", "/images/", etc. The images are in the jar file:

 fantasyhexwar/Images/plains100.gif
 fantasyhexwar/Images/quarry60.gif
 fantasyhexwar/Images/ram80.gif
 fantasyhexwar/Images/save map40.gif
 fantasyhexwar/Images/scout80.gif
 fantasyhexwar/Images/settler80.gif
 fantasyhexwar/Images/ship80.gif

etc...

I know I am missing something fundamental, but I'm not sure what. My suspicion is that it is something to do with the manifest file or possibly class path.

Hopefully someone can point me in the right direction...

EDIT: The problem seems to be that 

URL url = Terrain.class.getResource("/fantasyhexwar/Images/" + str);

returns null. The images are definitely in the JAR, and in desperation I have also tried all possible relative paths, with code like this:

ClassLoader cldr = Terrain.class.getClassLoader();
URL url = Terrain.class.getResource("/fantasyhexwar/Images/" + str);
if (url == null)
    url = cldr.getResource("/fantasyhexwar/fantasyhexwar/Images/" + str);
if (url == null)
    url = cldr.getResource("fantasyhexwar/fantasyhexwar/Images/" + str);
if (url == null)
    url = cldr.getResource("/fantasyhexwar/Images/" + str);
if (url == null)
    url = cldr.getResource("/Images/" + str);
if (url == null)
    url = cldr.getResource("Images/" + str);
if (url == null)
    url = cldr.getResource("/" + str);
if (url == null)
    url = cldr.getResource(str);
if (url == null)
    JOptionPane.showMessageDialog(null, "no good");

But none of it works when executing directly from the JAR...

When I try to run from the command line, I get:

java -cp .;FantasyHexWar.jar FantasyHexWarApp

Exception in thread "main" java.lang.NoClassDefFoundError: FantasyHexWarApp
Caused by: java.lang.ClassNotFoundException: FantasyHexWarApp
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
Could not find the main class: FantasyHexWarApp.  Program will exit.

Upvotes: 7

Views: 15997

Answers (7)

Darkcavie
Darkcavie

Reputation: 36

I had the same problem. The solution came to me reading the opinions about getToolkit() function. In my case I am building a desktop application, and the function getToolkit() is not avalaible for me. Instead I need to use this code:

Toolkit.getDefaultToolkit().getImage(ClassLoader.getSystemResource(path));

The program now functions in and out the Netbeans Environment.

Upvotes: 1

user2767882
user2767882

Reputation: 21

If the images are in the jar file, under fantasyhexwar/Images/.*,

Image image = getToolkit().getImage(ClassLoader.getSystemResource("fantasyhexwar/Images/plains100.gif"));

will work.

Upvotes: 2

Basil C Sunny
Basil C Sunny

Reputation: 424

Use this to display images from .jar files

ClassLoader.getSystemResource("images/Springz3.png");

Upvotes: 0

Fysh
Fysh

Reputation: 153

I was a little careless with my filenames. For example one file was called "save map.png", but the application was looking for "Save Map.png".

This worked fine when loading files from the drive, but when turned into a URL and loaded directly from the jar, it made all the difference.

Therefore, it seems that resource file names in a jar are case-sensitive.

Upvotes: 7

limc
limc

Reputation: 40160

I don't think it has anything to do with loading images from jar. The exception you get says:-

java.lang.ClassLoader.loadClass(Unknown Source) Could not find the main class: FantasyHexWarApp. Program will exit.

That means, FantasyHexWarApp main class is missing from the jar. Fix that and it should work just fine. :)

Upvotes: 0

camickr
camickr

Reputation: 324078

Read the section from the Swing tutorial on How to Use Icons for a detailed explanation of how this works.

Upvotes: 1

user489041
user489041

Reputation: 28294

Might be worth giving this a shot.


Image theImage = getToolkit().getImage(getClass().getResource("/path/to/image"))

Upvotes: 0

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