前言

        最近打算手写一个RPC，但奈何自己Java基础知识中的反射就很欠缺，第一章就看不太懂了，特地编写了几个小Demo验证一下Java中关于反射的基础知识。

目录组织结构

代码编写

// TestService接口
package reflect.testServices;

import main.version1.v1.common.pojo.User;

public interface TestService {
    User getUserById(Integer id);
    Integer insertUserById(User user);
}


// TestService1接口
package reflect.testServices;

import main.version1.v1.common.pojo.User;

public interface TestService1 {
    User getUserByName(String name);
}



// TestServiceImpl实现类
package reflect.testServices.impl;

import main.version1.v1.common.pojo.User;
import reflect.testServices.TestService;
import reflect.testServices.TestService1;

public class TestServiceImpl implements TestService, TestService1 {
    @Override
    public User getUserById(Integer id) {
        return null;
    }

    @Override
    public Integer insertUserById(User user) {
        return null;
    }

    @Override
    public User getUserByName(String name) {
        return null;
    }
}



// 测试Demo编写
package reflect;


import reflect.testServices.TestService;
import reflect.testServices.impl.TestServiceImpl;

import java.lang.reflect.Method;

public class Demo01 {
    public static void main(String[] args) throws NoSuchMethodException {
        System.out.println("=====");
        // 获取方法名
        Method getUserById = TestService.class.getMethod("getUserById", Integer.class);
        System.out.println(getUserById);
        // 获取方法对应的接口名
        System.out.println(getUserById.getDeclaringClass().getName());

        System.out.println("======");
        TestService testService = new TestServiceImpl();
        // 获取实现的接口字节码集合
        Class<?>[] interfaces = testService.getClass().getInterfaces();
        String name = testService.getClass().getName();
        System.out.println(name);
        // 遍历接口字节码集合
        for (Class<?> interfacea : interfaces) {
            // 获取接口名称
            System.out.println(interfacea.getName());
            // 遍历各个接口中定义的所有方法
            Method[] declaredMethods = interfacea.getDeclaredMethods();
            for (Method declaredMethod : declaredMethods) {
                System.out.println("innnnnnnn" + declaredMethod);
            }
        }
        System.out.println("=========");
        // 获取实现类中定义的所有方法
        Method[] methods = testService.getClass().getDeclaredMethods();
        for (Method method : methods) {
            System.out.println(method);
        }
    }
}

结果展示