Example of a shadingproof JNI binding.

NativeBinding.java

package com.shadeproof;

import net.bytebuddy.ByteBuddy;

public abstract class NativeBinding {

    public static final NativeBinding INSTANCE;

    static {
        System.load("mylibrary");
        String expected = "!com!shadeproof!NativeBinding!";
        expected = expected.substring(1, expected.length() - 1).replace('!', '.');
        if (NativeBinding.class.getName().equals(expected)) {
            INSTANCE = new DirectNativeBinding();
        } else {
            try {
                INSTANCE = new ByteBuddy()
                        .redefine(DirectNativeBinding.class)
                        .name(expected)
                        .make()
                        .load(NativeBinding.class.getClassLoader(), ClassLoadingStrategy.Default.INJECTION)
                        .getLoaded()
                        .getConstructor()
                        .newInstance();
            } catch (Exception e) {
                throw new IllegalStateException(e);
            }
        }
    }

    public abstract void method();

    private static class DirectNativeBinding extends NativeBinding {

        public native void method();
    }
}

Lacks ClassLoadingStrategy.Default.INJECTION, loading native code only works for the same class loader, the hierarchy is not applied for those.

ClassLoadingStrategy.Default.INJECTION does not work if the target class loader contains a non-shaded version as well as a shaded version, therefore ClassLoadingStrategy.Default.CHILD_FIRST seems more appropriate. To make sure the native library is loaded from the child class loader, it should be loaded form the static initializer of the DirectNativeBinding class. See also https://gist.github.com/felixbarny/3f519ac49520018aa8ecc82cae352670

Indeed, have not considered that case. Thanks for the hint, I'll keep it in the back in my head if I run into that.