Rewriting integer cache in Java - explanation here https://javapapers.com/java/java-integer-cache/

Main.java

import java.lang.reflect.Field;

public class Main {
    public static void main(String[] args) throws NoSuchFieldException, IllegalAccessException {
        final Class cache = Integer.class.getDeclaredClasses()[0];
        final Field cacheField = cache.getDeclaredField("cache");
        cacheField.setAccessible(true);

        final Integer[] array = (Integer[]) cacheField.get(cache);
        array[132] = 5;

        assert 5 == 2 + 2;
        // prints 5
        System.out.printf("%d\n", 2 + 2);
    }
}