How to export to a runnable jar with Proccessing (Eclipse)

Question

I have tried to export my processing applet to a runnable jar file from eclipse (which I am using to code it) and it exports successfully but when opened just causes a blank (grey) screen. If I run it with command prompt I get this error:

java.lang.NullPointerException: Cannot invoke "String.contains(java.lang.CharSequence)" because "jarPath" is null

When I extracted the jar sample the folders and directories seem to be incorrect too.

before (the dependencies are in the dependencies folder)

after (the dependencies are outside of the now missing dependencies folder)

I'm sure its an issue with the file structuring on generation, more specifically the dependencies. when I run it as an application eclipse it runs perfectly fine with no exceptions.

Full message:

java.lang.NullPointerException: Cannot invoke "String.contains(java.lang.CharSequence)" because "jarPath" is null
        at processing.core.PApplet.dataFile(PApplet.java:7673)
        at processing.core.PApplet.dataPath(PApplet.java:7650)
        at processing.core.PApplet.createInputRaw(PApplet.java:6741)
        at processing.core.PApplet.createInput(PApplet.java:6659)
        at processing.core.PApplet.loadBytes(PApplet.java:6959)
        at processing.awt.ShimAWT.loadImage(ShimAWT.java:384)
        at processing.core.PSurfaceNone.loadImage(PSurfaceNone.java:61)
        at processing.core.PApplet.loadImage(PApplet.java:5311)
        at processing.core.PApplet.loadImage(PApplet.java:5296)
        at net.turke1034.shootergame.game.ShooterGame.draw(ShooterGame.java:55)
        at processing.core.PApplet.handleDraw(PApplet.java:2201)
        at processing.awt.PSurfaceAWT$10.callDraw(PSurfaceAWT.java:1422)
        at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:354)
java.lang.NullPointerException: Cannot invoke "String.contains(java.lang.CharSequence)" because "jarPath" is null
        at processing.core.PApplet.dataFile(PApplet.java:7673)
        at processing.core.PApplet.dataPath(PApplet.java:7650)
        at processing.core.PApplet.createInputRaw(PApplet.java:6741)
        at processing.core.PApplet.createInput(PApplet.java:6659)
        at processing.awt.ShimAWT.loadImageIO(ShimAWT.java:454)
        at processing.awt.ShimAWT.loadImage(ShimAWT.java:439)
        at processing.core.PSurfaceNone.loadImage(PSurfaceNone.java:61)
        at processing.core.PApplet.loadImage(PApplet.java:5311)
        at processing.core.PApplet.loadImage(PApplet.java:5296)
        at net.turke1034.shootergame.game.ShooterGame.draw(ShooterGame.java:55)
        at processing.core.PApplet.handleDraw(PApplet.java:2201)
        at processing.awt.PSurfaceAWT$10.callDraw(PSurfaceAWT.java:1422)
        at processing.core.PSurfaceNone$AnimationThread.run(PSurfaceNone.java:354)

I have tried the same thing with a test project that requires no dependencies, and it runs as expected (when run in command prompt)

Have you tried exporting your application with processing? (You can do so on cli with "...processing-3.5.4\processing-java.exe" --sketch="Path to project" --force --export --platform 'windows'"). You could then look at the folder structure it generates and what's different from yours. Maybe exchange the processing generated jar with yours and see what happens (and maybe let us know). — Eskapone, May 06 '22 at 07:36
I have no knowledge of how the processing app works as I've only ever used it as a library. When I created an empty sketch with the app it was noticeably different to my files, having much more jars than mine, and has a folder called java that has a plethora of files, with mine not having a java folder all. I'm confused on what you're saying in the first bit, I tried opening the eclipse project with processing but it did not accept folders (or it) — turke1034, May 09 '22 at 02:26

score 1 · Answer 1 · answered May 13 '22 at 05:51

had the same issue, so troubleshooted for a while until i found the following solution. i'm assuming that you are using a data file similar to the data file in Processing projects to contain your dependencies.

in Eclipse, export as a runnable jar and select the option "Extract required libraries into generated JAR". once the jar is created, put this jar into a new folder. put your data folder into this folder as well. this worked for me.

no idea why this works - just threw stuff at the wall until this stuck. one troubleshooting technique i used was making a printwriter before loading any data so i could see where the computer was searching for the dependencies. the snippet below outputs the file to the same place that Processing looks for data.

    PrintWriter pw = createWriter(dataPath("test.txt"));
    pw.print("over here");
    pw.close();

i used this in combination with dataPath("") to find that it was looking for dependencies outside of the jar.

score 0 · Answer 2 · answered May 13 '22 at 12:02

0

In the past (older answer here) I had success exporting runnable .jar projects from eclipse which use Processing's libraries by using the Copy required libraries into a sub-folder next to the generated jar option in Runnable Jar File Export options:

This made it easier to debug java classpath issues (-cp flag when running from command line) and native library paths(-D.java.library.path command line flag).

If you're using java packages remember to specify them in PApplet.main():

public static void main(String[] args) {
        PApplet.main(ShooterGame.class.getCannonicalName());
    }

The above is useful only if you can't execute the jar files due to missing libraries (class not found, missing native libraries, etc.)

Regarding loading external assets, as Shivoum B mentions, you can make use of dataPath() but also sketchPath().(See this similar answer). Without seeing the path to the loadImage() call you're making I can only make assumptions, but you might be able to get away with something like this in ShooterGame.java:

loadImage(sketchPath("data" + File.separator + "yourImageName.png");

(Off-topic, if I read this correctly you're trying to load images in draw() ? I'd recommend loading all assets in setup() once instead of multiple times in draw(). A special case might be with the loading large assets that take time and using P2D or P3D where the OpenGL context setup might time out (in which you can load in draw() but should use a "debouncing" boolean to ensure assets are loaded only once)

answered May 13 '22 at 12:02

George Profenza

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I am loading images with booleans that make sure they haven't already been loaded, but when I export with the dependencies in a seperate folder, but I get this error: The file "src/net/turke1034/shootergame/resources/assets/image/paused.png" is missing or inaccessible, make sure the URL is valid or that the file has been added to your sketch and is readable. java.lang.NullPointerException: Cannot read field "width" because "img" is null – turke1034 May 18 '22 at 02:39
1

Oh yeah forget to mention this because I wasn't sure if its important, but the dependencies are in a folder inside the project – turke1034 May 18 '22 at 02:43
Interesting. I've just done a test: made an eclipse package named `src.net.turke1034.shootergame.resources.assets.image`, dropped paused.png into it and tried to load/show it: `image(loadImage("src/net/turke1034/shootergame/resources/assets/image/paused.png"), 0, 0, 100, 100);`. This worked both in eclipse and using the jar exporter via File > Export > Java > Runnable Jar option (with libs copied next to the jar). When I open the runnable .jar file as an archive (e.g. with 7-zip) I see the .png inside the archive. Do you see the png in the .jar you export ? ... – George Profenza May 18 '22 at 15:06
...can you also print the image path you're trying to load just before loading ? (I'm wondering if something malforms the path for some reason) – George Profenza May 18 '22 at 15:06
@turke1034 forgot to ask: what version of Processing are you using and on what operating system ? – George Profenza May 18 '22 at 17:09
The resources are there, and the path in loadImage() is src/net/turke1034/shootergame/resources/assets/image/paused.png. For some reason even the character which is a rectangle drawn with Processings rect() method doesn't show up, including the bullets it shoots (which are also rectangles). Also, when I open the jar, it has a weird random chance to show a grey bar at the top of the screen with a random height, sometimes not appearing, sometimes extending to over half the screen. Before when I had the dependencies inside the jar, it was fully grey. I am using processing 4.0b2 on Windows 10. - – turke1034 May 20 '22 at 01:29
- not to be stupid but how would I get the path processing is trying to use if the path is entered as a String parameter in the loadImage() method? The path that processing says is incorrect in the exception is also the exact path of the image. – turke1034 May 20 '22 at 01:35
1

I've now just realized that the grey portion of the screen is processing loading the background and the reason the rectangles do not render is simply because the first bit of code in the loop which creates and loads the image causes the exception which doesn't allow the code that renders the rectangles to be reached... That simplies the problem a lot though – turke1034 May 20 '22 at 01:51

How to export to a runnable jar with Proccessing (Eclipse)

2 Answers2