Reflections.java

package ysoserial.payloads.util;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;

import sun.reflect.ReflectionFactory;

@SuppressWarnings ( "restriction" )
public class Reflections {

	public static Field getField(final Class<?> clazz, final String fieldName) throws Exception {
		Field field = clazz.getDeclaredField(fieldName);
		if (field != null)
			field.setAccessible(true);
		else if (clazz.getSuperclass() != null)
			field = getField(clazz.getSuperclass(), fieldName);
		return field;
	}

	public static void setFieldValue(final Object obj, final String fieldName, final Object value) throws Exception {
		final Field field = getField(obj.getClass(), fieldName);
		field.set(obj, value);
	}

	public static Object getFieldValue(final Object obj, final String fieldName) throws Exception {
		final Field field = getField(obj.getClass(), fieldName);		
		return field.get(obj);
	}

	public static Constructor<?> getFirstCtor(final String name) throws Exception {
		final Constructor<?> ctor = Class.forName(name).getDeclaredConstructors()[0];
	    ctor.setAccessible(true);
	    return ctor;
	}
	

    public static <T> T createWithoutConstructor ( Class<T> classToInstantiate )
            throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
        return createWithConstructor(classToInstantiate, Object.class, new Class[0], new Object[0]);
    }
    
    @SuppressWarnings ( {"unchecked"} )
    public static <T> T createWithConstructor ( Class<T> classToInstantiate, Class<? super T> constructorClass, Class<?>[] consArgTypes, Object[] consArgs )
            throws NoSuchMethodException, InstantiationException, IllegalAccessException, InvocationTargetException {
        Constructor<? super T> objCons = constructorClass.getDeclaredConstructor(consArgTypes);
        objCons.setAccessible(true);
        Constructor<?> sc = ReflectionFactory.getReflectionFactory().newConstructorForSerialization(classToInstantiate, objCons);
        sc.setAccessible(true);
        return (T)sc.newInstance(consArgs);
    }

}