Java反射 - getDeclaredConstructor().newInstance()得到实例化对象

Java反射 - getDeclaredConstructor().newInstance()得到实例化对象

• class.newInstance()实例化只能直接调用构造参数
• class.getDeclaredConstructor().newInstance()实例化可以调用静态类和构造参数

实现类

public static void main(String[] args) throws NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException {
    UserService.class.getDeclaredConstructor().newInstance();
    System.out.println("=====================");
    UserService.class.newInstance();
}

class对象代码

public class UserService {

    static {
        System.out.println("static");
    }
    
    public UserService() {
        System.out.println("test");
    }
}

得到的结果

标签：Java,newInstance,System,实例,getDeclaredConstructor,UserService,class
来源： https://www.cnblogs.com/HeiDaotu/p/15618894.html