java学习(1) ----getMethod()和getDeclaredMethod()的区别(转)

转自: https://blog.csdn.net/qq_36443736/article/details/82890011

getMethod（）：获取自身能用所有的公共方法。1.类本身的public 2.继承父类的public 3.实现接口的public

getDeclaredMethod（）：获取类自身声明的所有方法。

getMethod（）获取继承父类的public方法举例：

public class Father {
 
    public Father() {
        System.out.println("调用了父类构造方法");
    }
    
    public void fatherSay() {
        System.out.println("我是爸爸");
    }
}
 
 
public class Son extends Father {
 
    public Son() {
    
        // TODO Auto-generated constructor stub
        System.out.println("调用了子类构造方法");
    }
    
    public void sonSay() {
        System.out.println("我是儿子");
    }
    public static void main(String[] args) {
        Son son=new Son();
        son.fatherSay();
    }
}

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测试类：

public class test1 {
 
    public static void main(String[] args) {
        Class clazz=Son.class;
        try {
              //报错 NoSuchMethodException
            Method method =clazz.getDeclaredMethod("fatherSay");
            method.invoke(clazz.newInstance());
            
                //运行结果:
                //调用了父类构造方法
                //调用了子类构造方法
                //我是爸爸
            Method method2 =clazz.getMethod("fatherSay");
            method2.invoke(clazz.newInstance());
 
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (InstantiationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
    }
}

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原文地址：https://www.cnblogs.com/Lee-yl/p/11512889.html