教你创建springcloud微服务的基础子服务的超详细过程

一、创建父项目

1. 选择Spring Initializr

2. Type选择为Maven POM，Java Version选择为8

3. 勾选一些基本的依赖，如lombok和spring-boot-starter-web

4. 创建好了的父项目结构如下：

二、创建二级项目

1. 选择新建Module

2. 选择Maven

3. 填写Name

4. 修改openfeign pom.xml文件，并删除掉该项目下的src文件

5. 创建完成的项目结构如下

三、创建子项目feign-provider、feign-consumer、feign-api

1. 在feign-provider项目上新建模块

2. 选择Parent为openfeign-stu

3. 同上步骤创建feign-consumer、feign-api，创建完成后的整体项目结构如下：

四、完善feign-api、feign-provider、feign-consumer项目

1. springcloud-stu pom.xml中去掉spring-boot-maven-plugin

修改为如下：

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <packaging>pom</packaging>
    <modules>
        <module>openfeign-stu</module>
    </modules>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.6</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.wq</groupId>
    <artifactId>springcloud-stu</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springcloud-stu</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    
</project>

2. openfeign-stu pom.xml中修改为如下：

<?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">
    <parent>
        <artifactId>springcloud-stu</artifactId>
        <groupId>com.wq</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>openfeign-stu</artifactId>
    <packaging>pom</packaging>
    <modules>
        <module>feign-provider</module>
        <module>feign-consumer</module>
        <module>feign-api</module>
    </modules>
    <dependencies>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.2</version>
    </dependencies>
</project>

3. feign-api 完善

feign-api的项目清单如下：

Result的内容如下：

package com.wq.feign.api.domain;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
@Data
@NoArgsConstructor
@AllArgsConstructor
public class Result {
    private int code;
    private String msg;
    private Object data;
}

pom.xml内容就是创建时的内容，不做改动

4. feign-provider 完善

完善后的项目结构如下：

4.1 pom.xml添加feign-api依赖，及增加spring-boot-maven-plugin插件

修改为如下：

<?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">
    <parent>
        <artifactId>openfeign-stu</artifactId>
        <groupId>com.wq</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>feign-provider</artifactId>
    
    <dependencies>
        <dependency>
            <groupId>com.wq</groupId>
            <artifactId>feign-api</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

4.2 ProductController.java

package com.wq.feign.provider.controller;
import com.wq.feign.api.domain.Result;
import com.wq.feign.provider.domain.entity.Product;
import com.wq.feign.provider.service.ProductService;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;
import javax.annotation.Resource;
@RestController
@Slf4j
@RequestMapping("/")
public class ProductController {
    @Resource
    private ProductService productService;
    /**
     * 查询
     * @param id
     * @return
     */
    @GetMapping("product/provider/get/{id}")
    public Result selectById(@PathVariable("id") Long id){
        return new Result(200, "查询成功", productService.selectById(id));
    }
     * 删除
    @GetMapping("product/provider/delete/{id}")
    public Result deleteById(@PathVariable("id") Long id){
        return new Result(200, "删除成功", productService.deleteById(id));
     * 修改
     * @param product
    @PostMapping("product/provider/update")
    public Result updateById(@RequestBody Product product){
        return new Result(200, "修改成功", productService.updateById(product.getId(), product.getName()));
     * 新增
    @PutMapping( "product/provider/add")
    public Result insertById(@RequestBody Product product){
        return new Result(200, "修改成功", productService.insertOne(product));
}

4.3 ProductMapper.xml

package com.wq.feign.provider.dao;
import com.wq.feign.provider.domain.entity.Product;
import org.apache.ibatis.annotations.Param;
import org.springframework.stereotype.Repository;
@Repository
public interface ProductMapper {
    /**
     * 查询
     * @param id
     * @return
     */
    public Product selectById(@Param("id") Long id);
     * 删除
    public int deleteById(@Param("id") Long id);
     * 修改
     * @param name
    public int updateById(@Param("id") Long id, @Param("name") String name);
     * 新增
     * @param product
    public int insertOne(Product product);
}

4.4 Product.java

package com.wq.feign.provider.domain.entity;
import lombok.Data;
@Data
public class Product {
    private Long id;
    private String name;
    private int stock;
}

4.5 ProductServiceImpl.java

package com.wq.feign.provider.service.impl;
import com.wq.feign.provider.dao.ProductMapper;
import com.wq.feign.provider.domain.entity.Product;
import com.wq.feign.provider.service.ProductService;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
@Service
public class ProductServiceImpl implements ProductService {
    @Resource
    private ProductMapper productMapper;
    public Product selectById(Long id) {
        return productMapper.selectById(id);
    }
    public int deleteById(Long id) {
        return productMapper.deleteById(id);
    public int updateById(Long id, String name) {
        return productMapper.updateById(id, name);
    public int insertOne(Product product) {
        return productMapper.insertOne(product);
}

4.6 ProductService.java

package com.wq.feign.provider.service;
import com.wq.feign.provider.domain.entity.Product;
/**
 * 商品服务类
 */
public interface ProductService {
    /**
     * 查询
     * @param id
     * @return
     */
    public Product selectById(Long id);
     * 删除
    public int deleteById(Long id);
     * 修改
     * @param name
    public int updateById(Long id, String name);
     * 新增
     * @param product
    public int insertOne(Product product);
}

4.7 ProviderApplication.java

package com.wq.feign.provider;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.wq.feign.provider.dao")
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
}

4.8 ProductMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.wq.feign.provider.dao.ProductMapper">
    <resultMap id="BaseResultMap" type="com.wq.feign.provider.domain.entity.Product">
        <result column="id" jdbcType="BIGINT" property="id" />
        <result column="name" jdbcType="VARCHAR" property="name" />
        <result column="stock" jdbcType="INTEGER" property="stock" />
    </resultMap>
    <!--查询-->
    <select id="selectById" resultType="com.wq.feign.provider.domain.entity.Product">
        select * from product where id = #{id}
    </select>
    <!--删除-->
    <delete id="deleteById" parameterType="java.lang.Long">
        delete from product where id = #{id}
    </delete>
    <!--修改-->
    <update id="updateById" parameterType="com.wq.feign.provider.domain.entity.Product">
        update product set name = #{name} where id = #{id}
    </update>
    <!--新增-->
    <insert id="insertOne" parameterType="com.wq.feign.provider.domain.entity.Product">
       insert into product(name, stock) values (#{name}, #{stock})
    </insert>
</mapper>

4.9 application.yml

server:
  port: 8081
spring:
  application:
    name: feign-provider-8081
  datasource:
    url: jdbc:mysql://localhost:3306/springcloud-stu?useUnicode=true&characterEncoding=utf8&userSSL=false
    driverClassName: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
mybatis:
  mapper-locations: classpath:mapper/*Mapper.xml # Mybatis 映射文件位置
  type-aliases-package: com.wq.feign.provider.domain.entity  # 表对应的实体类包

4.10 sql脚本

DROP TABLE IF EXISTS `product`;
CREATE TABLE `product`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `stock` int(10) UNSIGNED NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB AUTO_INCREMENT = 4 CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of product
INSERT INTO `product` VALUES (1, '华为 mate10', 10);
INSERT INTO `product` VALUES (2, '华为 mate20', 20);
INSERT INTO `product` VALUES (3, '华为 mate30', 30);

5. feign-consumer 完善

完善后的项目结构如下

5.1 pom.xml添加feign-api依赖，及增加spring-boot-maven-plugin插件

<?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">
    <parent>
        <artifactId>openfeign-stu</artifactId>
        <groupId>com.wq</groupId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
    <artifactId>feign-consumer</artifactId>
    <dependencies>
        <dependency>
            <groupId>com.wq</groupId>
            <artifactId>feign-api</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
    </dependencies>
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>
</project>

5.2 RestConfig.java

package com.wq.feign.consumer.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
@Configuration
public class RestConfig {
    @Bean
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

5.3 ProductConsumerController.java

package com.wq.feign.consumer.controller;
import com.wq.feign.api.domain.Result;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import javax.annotation.Resource;
@RestController
public class ProductConsumerController {
    @Resource
    RestTemplate restTemplate;
    public static String url = "http://localhost:8081/";
    /**
     * 查询
     * @param id
     * @return
     */
    @GetMapping("product/consumer/get/{id}")
    public Result selectById(@PathVariable("id") Long id){
        return restTemplate.getForObject(url+"product/provider/get/"+id, Result.class);
    }
}

5.4 ConsumerApplication.java

package com.wq.feign.consumer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
@SpringBootApplication(exclude={DataSourceAutoConfiguration.class})
public class ConsumerApplication {
    public static void main(String[] args) {
        SpringApplication.run(ConsumerApplication.class, args);
    }
}

5.5 application.yml

server:
  port: 8082
spring:
  application:
    name: feign-consumer-8082

五、测试项目

启动ProviderApplication和ConsumerApplication

使用浏览器访问，得到结果如下：

六总结

我们至此创建了一个多模块的项目，然后有一个商品服务提供者feign-provider-8081 和一个商品服务消费者feign-consumer-8082 。

然后这就是最简单的两个微服务了，实现了功能的解耦。

但是这个简单的微服务存在着很多问题：

比如都用公共的实体类Result，还有提供者地址在消费者里面写死了等等，这些问题，我们接下来会一一解决。