Why the exported to desktop (.exe) processing app with java classes can not run properly? My another project was exported without problems

Question

I try to export my processing app as the "ready to use" application with exe launch file for desktop. My code is pretty simple. Proccessing code:

//import io.itch.mgdsstudio.airfight.connecteddevices.*;
private io.itch.mgdsstudio.airfight.connecteddevices.Controller controller;   
       
void setup(){   
  size(600,800,  JAVA2D);
   background(0);
   //I think the next code line can not be launched after export. Background stays black
   controller = new io.itch.mgdsstudio.airfight.connecteddevices.Controller(this);
}

void draw(){      
  controller.render();        
}

and the java-class:

package io.itch.mgdsstudio.airfight.connecteddevices;
import processing.core.PApplet;

public class Controller {
   private PApplet engine;

    public Controller(PApplet engine) {
       this.engine = engine;
    }
   
    public void render(){
        engine.background(255,0,0);        
    }
}

The application runs perfect from processing ide - the screen is red. But after export it can not run properly. The screen is black. I tested processing 3 and 4. In january I exported an another application succesfully. But now I can not launch exported file. I think the trouble is in versions of the java source files.

I tried to change code so:

import io.itch.mgdsstudio.airfight.connecteddevices.Controller;
private Controller controller;   

void setup(){   
  size(600,800,  JAVA2D);
   background(0);   
   controller = new Controller(this);
}

void draw(){      
  controller.render();        
}

I receive the message in the console: No library found for io.itch.mgdsstudio.airfight.connecteddevices but it runs in the ide. But after export it can not run properly again. Maybe i need another package names?

Answer 1

There seems to be an issue/bug using package inside the Processing IDE.

As you hinted in your comments, if you could compile a .jar in your Java IDE of choice and use that in Processing that should work.

From a pragmatic point of view, if you don't plan on fixing the Processing IDE to handle package as expected, you can simply not use it your code:

import processing.core.PApplet;

public class Controller {
   private PApplet engine;

    public Controller(PApplet engine) {
       this.engine = engine;
    }
   
    public void render(){
        engine.background(255,0,0);        
    }
}
Controller controller;
       
void setup(){   
  size(600,800,  JAVA2D);
   background(0);
   controller = new Controller(this);
}

void draw(){      
  controller.render();        
}

This wouldn't be convenient on a larger project where you may want to write Java code in your preferred IDE but still be able to colaborate with others that use the Processing IDE alone.

Since running in the Processing IDE works (e.g. dev/testing), but can't export a .exe for easy deployment, a workaround could be using the processing-java command. (If you add your Processing installation folder to the Windows %PATH% environment variable you should be able to type processing-java in a new Command Prompt window and see the help/usage guide).

Running processing-java --sketch=path\to\YourSketchFolder --run should run the sketch the same way the Processing IDE does (without actually having the IDE open). While this implies installing Processing and adding it to %PATH% on any new machine on one hand, on the other it saves you the time of having rebuild/repackage new .exe files for every single change.