1. SpringCloud

2. Nacos

3. 远程通信

就是在互不相干的模块里调用其他模块的接口
本章内容父项目pom文件结构

<?xml version="1.0" encoding="UTF-8"?>

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>
  <groupId>com.jmh</groupId>
  <artifactId>springcloud01</artifactId>
  <version>1.0-SNAPSHOT</version>
  <!--pom代表这个是个父工程-->
  <packaging>pom</packaging>

  <!--指向儿子-->
  <modules>
    <module>nacos_provider</module>
    <module>nacos_consumer</module>
    <module>nacos_commons</module>
  </modules>

  <name>springcloud01 Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <!--提供版本-->
  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
    <spring-boot.version>2.4.1</spring-boot.version>
    <spring-cloud.version>2020.0.0</spring-cloud.version>
    <spring-cloud-alibaba.version>2021.1</spring-cloud-alibaba.version>
  </properties>

  <!--提供依赖-->
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
    </dependency>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!--注册与发现-->
    <dependency>
      <groupId>com.alibaba.cloud</groupId>
      <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
    </dependency>
    <!--远程通信-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
    <!--负载均衡-->
    <dependency>
      <groupId>org.springframework.cloud</groupId>
      <artifactId>spring-cloud-loadbalancer</artifactId>
    </dependency>
    <!--对象赋值依赖-->
    <dependency>
      <groupId>ma.glasnost.orika</groupId>
      <artifactId>orika-core</artifactId>
      <version>1.4.6</version>
    </dependency>
    <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
    </dependency>
    <!--子模块nacos_commons依赖-->
    <dependency>
      <groupId>com.jmh</groupId>
      <artifactId>nacos_commons</artifactId>
      <version>0.0.1-SNAPSHOT</version>
    </dependency>
  </dependencies>

  <!--提供依赖版本-->
  <dependencyManagement>
    <dependencies>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-dependencies</artifactId>
        <version>${spring-boot.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>${spring-cloud.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
      <dependency>
        <groupId>com.alibaba.cloud</groupId>
        <artifactId>spring-cloud-alibaba-dependencies</artifactId>
        <version>${spring-cloud-alibaba.version}</version>
        <type>pom</type>
        <scope>import</scope>
      </dependency>
    </dependencies>
  </dependencyManagement>


</project>

3.1 创建公共子模块 (nacos_commons)

3.1.1 DTO对象

VO（View Object）：视图对象，用于展示层，它的作用是把某个指定页面（或组件）的所有数据封装起来。
DTO（Data Transfer Object）：数据传输对象，这个概念来源于J2EE的设计模式，原来的目的是为了EJB的分布式应用提供粗粒度的数据实体，以减少分布式调用的次数，从而提高分布式调用的性能和降低网络负载，但在这里，我泛指用于展示层与服务层之间的数据传输对象。
DO（Domain Object）：领域对象，就是从现实世界中抽象出来的有形或无形的业务实体。
PO（Persistent Object）：持久化对象，它跟持久层（通常是关系型数据库）的数据结构形成一一对应的映射关系，如果持久层是关系型数据库，那么，数据表中的每个字段（或若干个）就对应 PO的一个（或若干个）属性。

消费者远程调用生产者 : 需要网络传输,使用DTO同一封装对象

原理与SpringBoot启动类相同

1.将DTO对象封装到公共DTO模块

2.为需要的项目引入公共DTO模块

注意点

1.不需要继承父模块(重复引用问题)

2.打包方式为jar

3.不需要添加启动类的编译

创建UserDto对象

package com.jmh.nacos_commons.dto;

import lombok.Data;

/**
 * @author 蒋明辉
 * @data 2022/11/4 17:28
 */
@Data
public class UserDto {
    //账号
    private String names;
    //密码
    private String pwd;
    //秘钥
    private String token;
}

打包点击要打包的项目右键点击Run Maven 选择Install

3.2 父项目引入子项目 (nacos_commons) 打成的jar包

<!--子模块nacos_commons依赖-->
    <dependency>
      <groupId>com.jmh</groupId>
      <artifactId>nacos_commons</artifactId>
      <version>0.0.1-SNAPSHOT</version>
    </dependency>

3.3 父项目指向子项目 (nacos_commons) 为儿子

注意！子项目不需要继承父模块(重复引用问题)

<modules>
    <module>nacos_commons</module>
  </modules>

3.4 子项目 (nacos_provider)

Orika

Orika是java Bean映射框架，可以实现从一个对象递归拷贝数据至另一个对象。

pojo模块

package com.jmh.nacos_provider.pojo;

import lombok.Data;

/**
 * @author 蒋明辉
 * @data 2022/11/4 17:28
 */
@Data
public class User {
    //账号
    private String name;
    //密码
    private String pwd;
}

启动类配置

package com.jmh.nacos_provider;

import ma.glasnost.orika.MapperFactory;
import ma.glasnost.orika.impl.DefaultMapperFactory;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Scope;

@SpringBootApplication
@EnableDiscoveryClient
@SuppressWarnings("all")
public class NacosProviderApplication {

    public static void main(String[] args) {
        SpringApplication.run(NacosProviderApplication.class, args);
    }

    @Bean
    /*单例模式：原型链*/
    @Scope("prototype")
    public MapperFactory mapperFactory() {
        return new DefaultMapperFactory.Builder().build();
    }

}

controller模块

package com.jmh.nacos_provider.controller;

import com.jmh.nacos_commons.dto.UserDto;
import com.jmh.nacos_provider.pojo.User;
import ma.glasnost.orika.MapperFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.Map;

/**
 * @author 蒋明辉
 * @data 2022/11/4 17:29
 */
@RestController
@RequestMapping("/user")
@SuppressWarnings("all")
public class UserController {

    @Autowired
    private MapperFactory factory;

    @RequestMapping("/{name}")
    public String getByPath(@PathVariable("name") String name){
        System.out.println("name=" + name);
        return "我是生产者: yes";
    }

    @RequestMapping("/param")
    public String getByParam(@RequestParam("name") String name,@RequestParam("pwd") String pwd){
        System.out.println("name=" + name);
        System.out.println("pwd=" + pwd);
        return "我是生产者: yes";
    }

    @RequestMapping("/pojo")
    public String getByPojo(@RequestBody UserDto userDto){
        //属性值一样
        //User u = factory.getMapperFacade().map(userDto, User.class);
        //属性值那不一样
        factory.classMap(UserDto.class, User.class)
                .field("names", "name")
                .byDefault().register();
        User u = factory.getMapperFacade().map(userDto, User.class);
        System.out.println("user=" + u);
        return "我是生产者: yes";
    }

    @RequestMapping("/map")
    public String getByMap(@RequestBody Map<String,Object> map){
        System.out.println("map=" + map);
        return "我是生产者: yes";
    }



}

3.5 子项目 (nacos_consumer)

现在为什么来了现在我在互不相干的模块中怎么去调用呢？用什么方法去调用呢？生产者提供接口：可以使用以下几个注解接收远程调用的参数值：

@PathVariable
@RequestParam
@RequestBody
@RestController

启动类配置

package com.jmh.nacos_consumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
@SuppressWarnings("all")
public class NacosConsumerApplication {

    public static void main(String[] args) {
        SpringApplication.run(NacosConsumerApplication.class, args);
    }

}

编写远程访问接口

package com.jmh.nacos_consumer.service;

import com.jmh.nacos_commons.dto.UserDto;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.*;

import java.util.Map;

/**
 * @author 蒋明辉
 * @data 2022/11/4 17:29
 */
@FeignClient("nacos-provider")
@SuppressWarnings("all")
public interface IFeignUserService {

    @RequestMapping("/user/{name}")
    String getByPath(@PathVariable("name") String name);

    @RequestMapping("/user/param")
    String getByParam(@RequestParam("name") String name,@RequestParam("pwd") String pwd);

    @RequestMapping("/user/pojo")
    String getByPojo(@RequestBody UserDto user);

    @RequestMapping("/user/map")
    String getByMap(@RequestBody Map<String,Object> map);



}

controller模块

package com.jmh.nacos_consumer.controller;

import com.jmh.nacos_commons.dto.UserDto;
import com.jmh.nacos_consumer.service.IFeignUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Map;

/**
 * @author 蒋明辉
 * @data 2022/11/4 18:27
 */
@RestController
@RequestMapping("/user")
@SuppressWarnings("all")
public class UserController {

    @Autowired
    private IFeignUserService service;

    @RequestMapping("/{name}")
    public String test01(@PathVariable("name") String name){
        service.getByPath(name);
        return "我是消费者: yes";
    }

    @RequestMapping("/test02")
    public String test02(String name,String pwd){
        service.getByParam(name,pwd);
        return "我是消费者: yes";
    }

    @RequestMapping("/test03")
    public String test03(@RequestBody UserDto user){
        service.getByPojo(user);
        return "我是消费者: yes";
    }

    @RequestMapping("/test04")
    public String test04(@RequestBody Map map){
        service.getByMap(map);
        return "我是消费者: yes";
    }

    @RequestMapping("/test05")
    public String test05(String name){
        service.getByPath(name);
        return "我是消费者: yes";
    }


}