It is possible to use to access class private instance variables and methods using Reflexion.

Access to private instance variables

MyClass myClass = new MyClass();
Field field = MyClass.class.getDeclaredField("myField");
field.setAccessible(true);
Object value = field.get(myClass);
System.out.println(value);

Access to private methods

MyClass myClass = new MyClass();
Method method = myClass.getClass().getDeclaredMethod("myMethodName");
method.setAccessible(true);
Object o = method.invoke(object);