threadSet=Thread.getAllStackTraces().keySet();
//It iterates upon the threads to find ones dispatched by PSurfaceJOGL
for (Thread th : threadSet) {
iteration:
{
try {
//Field f=th.getClass().getDeclaredField("target");
//f.setAccessible(true);
Object currinstance=null;
//Here Unsafe is used to breach encapsulation of java.lang
currinstance=unsafe.getObject(th, fieldIndex);
if (!currinstance.getClass().toString().contains("PSurfaceJOGL$")) break iteration;
//System.out.println("Weak spot found! "+th.getName());
//gets the PSurfaceJOGL
currinstance=getEnclosingInstance(currinstance);
//gets the PApplet
Field f=PSurfaceJOGL.class.getDeclaredField("sketch");
f.setAccessible(true);
allFoundPapplets.add((PApplet) (currinstance=f.get(currinstance)));
//System.out.println("Detection successful");
}
catch(Exception e)
{
catchBlock:
{
if (e instanceof NoSuchFieldException||e instanceof NullPointerException) {
//System.err.println("target not found "+th.getName());
//A NullPointerException may occur
break catchBlock;
}
//System.err.println("Something went wrong!");
e.printStackTrace();
}
}
}
}
}
//This will try to get the enclosing instance of an object (this can also be a lambda)
public static Object getEnclosingInstance(Object o) {
//This code will work for Processing 3 (uses annonymous inner classes)
try {
Class classused=o.getClass();
Field this0=classused.getDeclaredField("this$0");
this0.setAccessible(true);
return this0.get(o);
}
catch(Exception e) {
//System.err.println("Can't find enclosing instance of Object, trying to use Lambdas... (To be expected with Processing 4)");
}
//This code should work for Processing 4 (lambdas are used instead of inner classes, Lambdas use arg$1 instead this$0)
try {
Class classused=o.getClass();
Field this0=classused.getDeclaredField("arg$1");
this0.setAccessible(true);
return this0.get(o);
}
catch(Exception e) {
//System.err.println("Detection Failed!");
}
return null;
}
}
```
This is the code of the main sketch:
**MainSketch.pde**
```auto
void setup() {
size(300,300,JAVA2D);
println(this,PAppletFinder.getPApplets(false)[0]);
}
void draw() {
}
```
This should print something like:
MainSketch@64638317 [MainSketch@64638317]
If it doesn’t please wirte the contents of the console, so I can try to debug it.
Please also test this code with P3D and P2D.
---
### Author:  [@NumericPrime](https://discourse.processing.org/u/NumericPrime)
#### Post date: [September 24, 2022, 4:27pm UTC](https://discourse.processing.org/t/tester-for-the-pappletfinder-in-processing-4-required/38914/2 "2022-09-24T16:27:55Z")
I had a friend run the code and it seems it doesn’t work for P2D and P3D in Processing 4.
The Problem is the following:
Java 17 made the .setAccessible methods for the java.lang.\* classes not work anymore.
When I try to access a field of **java.lang.** Thread it won’t work anymore. So back to the drawing board.
---
### Author:  [@GoToLoop](https://discourse.processing.org/u/GoToLoop)
#### Post date: [September 24, 2022, 5:35pm UTC](https://discourse.processing.org/t/tester-for-the-pappletfinder-in-processing-4-required/38914/3 "2022-09-24T17:35:09Z")
> [@Get the current instance of PApplet from a library](https://discourse.processing.org/t/get-the-current-instance-of-papplet-from-a-library/36925/25):
>
> Since Java 9 method [setAccessible()](https://docs.oracle.com/javase/9/docs/api/java/lang/reflect/AccessibleObject.html#setAccessible-boolean-) also takes into consideration the module a reflected member belongs to: [https://en.Wikipedia.org/wiki/Java\_Platform\_Module\_System#Properties\_of\_modules](https://en.Wikipedia.org/wiki/Java_Platform_Module_System#Properties_of_modules) There’s an --add-opens option for the Java’s command-line, but dunno how to add that to Processing: [OpenJDK.org/jeps/261#Breaking-encapsulation](http://OpenJDK.org/jeps/261#Breaking-encapsulation)
---
### Author:  [@NumericPrime](https://discourse.processing.org/u/NumericPrime)
#### Post date: [September 24, 2022, 6:31pm UTC](https://discourse.processing.org/t/tester-for-the-pappletfinder-in-processing-4-required/38914/4 "2022-09-24T18:31:40Z")
I might be able to do something with Unsafe:
```auto
import sun.misc.*;
import java.lang.reflect.*;
try{
Field f2=Unsafe.class.getDeclaredField("theUnsafe");
f2.setAccessible(true);
Unsafe o=(Unsafe) f2.get(null);
System.out.println("Unsafe instance: "+o.toString());
}catch(Exception e){e.printStackTrace();}
```
If this works with processing 4 I can try to use Unsafe to basicly do the same reflection does.
---
### Author:  [@NumericPrime](https://discourse.processing.org/u/NumericPrime)
#### Post date: [September 25, 2022, 3:35pm UTC](https://discourse.processing.org/t/tester-for-the-pappletfinder-in-processing-4-required/38914/5 "2022-09-25T15:35:41Z")
> [@Get the current instance of PApplet from a library](https://discourse.processing.org/t/get-the-current-instance-of-papplet-from-a-library/36925/27):
>
> This code might do the trick. It also works with processing 3 and this code is able to breach encapsulation. (As long as there is no SecurityManager in place) PAppletFinder.java import processing.awt.\*; import processing.opengl.\*; import processing.core.\*; import javax.swing.\*; import java.awt.\*; import java.util.\*; import java.lang.reflect.\*; import sun.misc.\*; /\*\*This class finds the active PApplet (Processing program)\*/ public class PAppletFinder { /\*\*Unsafe instance used\*/ public sta…
---
### Author:  [@NumericPrime](https://discourse.processing.org/u/NumericPrime)
#### Post date: [September 25, 2022, 7:15pm UTC](https://discourse.processing.org/t/tester-for-the-pappletfinder-in-processing-4-required/38914/6 "2022-09-25T19:15:18Z")
Good news everyone!
I managed to fix the issues arising from Processings change to Java 17. A friend of mine ran the code with Processing 4 and it works with the JAVA2D, P2D and P3D renderers.
I already fixed the code in the original post. Soon I will update the commentary and comment out the print commands.
If anyone got questions about how the code works feel free to ask!