Injecting objects in a static field - reflection hack; useful for testing, when you couldn't inject mock via constructor

InjectUtils.java

package utils;

import java.lang.reflect.Field;
import java.lang.reflect.Modifier;
import java.util.function.Consumer;

public interface InjectUtils {

    String MODIFIERS = "modifiers";

    static boolean injectFinalStaticField(Class<?> clazz, String fieldName, Object newValue) {
        return injectFinalStaticField(clazz, fieldName, newValue, (e) -> e.printStackTrace());
    }

    static boolean injectFinalStaticField(Class<?> clazz,
                                          String fieldName,
                                          Object newValue,
                                          Consumer<Throwable> exceptionHandler) {
        try {
            Field modifiersField = Field.class.getDeclaredField(MODIFIERS);
            modifiersField.setAccessible(true);
            Field field = clazz.getDeclaredField(fieldName);
            field.setAccessible(true);
            modifiersField.setInt(field, field.getModifiers() & ~Modifier.FINAL);

            field.set(null, newValue);

            modifiersField.setInt(field, field.getModifiers() | Modifier.FINAL);
            field.setAccessible(false);
        } catch (NoSuchFieldException | IllegalAccessException e) {
            exceptionHandler.accept(e);
        }

        return true;
    }
}