【通过反射获取成员方法并使用】

package com.yjf.esupplier.common.test;

import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

/**
 * @author shusheng
 * @description 通过反射获取成员方法并使用
 * @Email shusheng@yiji.com
 * @date 2019/1/5 18:37
 */
public class ReflectDemo3 {

    public static void main(String[] args) throws Exception {
        // 获取字节码文件对象
        Class c = Class.forName("com.yjf.esupplier.common.test.Person");

        // 获取自己的包括父亲的公共方法
        Method[] methods1 = c.getMethods();
        for (Method method : methods1) {
            System.out.println(method);
        }
        System.out.println("-------------------------------");
        // 获取自己的所有的方法
        Method[] methods2 = c.getDeclaredMethods();
        for (Method method : methods2) {
            System.out.println(method);
        }
        System.out.println("-------------------------------");
        //通过无参构造方法拿到对象
        Constructor con = c.getConstructor();
        Object obj = con.newInstance();
        //获取单个方法并使用
        Method m1 = c.getMethod("show");
        m1.invoke(obj);
        System.out.println("-------------------------------");
        //第一个参数表示对象是谁，第二参数表示调用该方法的实际参数
        Method m2 = c.getMethod("method", String.class);
        m2.invoke(obj, "Hello");
        System.out.println("-------------------------------");
        // 返回值是Object接收
        Method m3 = c.getMethod("getString", String.class, int.class);
        Object objString = m3.invoke(obj, "hello", 100);
        String s = (String) m3.invoke(obj, "hello", 100);
        System.out.println(objString);
        System.out.println(s);
        System.out.println("-------------------------------");
        // private void function()
        Method m4 = c.getDeclaredMethod("function");
        m4.setAccessible(true);
        m4.invoke(obj);
    }

}

package com.yjf.esupplier.common.test;

/**
 * @author shusheng
 * @description
 * @Email shusheng@yiji.com
 * @date 2018/12/29 13:42
 */
public class Person {

        private String name;
        int age;
        public String address;

        public Person() {
        }

        private Person(String name) {
            this.name = name;
        }

        Person(String name, int age) {
            this.name = name;
            this.age = age;
        }

        public Person(String name, int age, String address) {
            this.name = name;
            this.age = age;
            this.address = address;
        }

        public void show() {
            System.out.println("show方法的输出");
        }

        public void method(String s) {
            System.out.println("method方法的输出： " + s);
        }

        public String getString(String s, int i) {
            return s + "---" + i;
        }

        private void function() {
            System.out.println("function方法的输出");
        }

        @Override
        public String toString() {
            return "Person [name=" + name + ", age=" + age + ", address="
                    + address
                    + "]";
        }

}