通過反射創建構造函數爲private修飾的對象

CarFactory instance = CarFactory.getInstance();
Class<?> aClass = Class.forName("com.jsdc.tianqi.danli.CarFactory");//這個CarFacotry是一個單例，構造方法private
Constructor<?> declaredConstructor = aClass.getDeclaredConstructor();
declaredConstructor.setAccessible(true);//這裏很重要，設置爲true 
Object o = declaredConstructor.newInstance();