# 构建Spring Cloud工程
#### 创建父工程
1. 创建Maven工程。 
   图1创建Maven工程   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859423037.png)
   
   
2. 父pom添加依赖。 
   ```
   <dependencyManagement>
       <dependencies>
           <dependency>
               <groupId>org.springframework.boot</groupId>
               <artifactId>spring-boot-dependencies</artifactId>
               <version>2.2.8.RELEASE</version>
               <type>pom</type>
               <scope>import</scope>
           </dependency>
       </dependencies>
   </dependencyManagement>
   ```
   
   
#### 创建子工程ServiceA
1. 创建Maven工程。 
   图2创建Maven工程   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859423373.png)
   
   
2. 新建src目录。 
   图3新建src目录   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859503865.png)
   
   
3. 编写业务代码。 
   图4业务代码文件   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859517765.png)
   1. 编写启动类
      ```
      package com.huawei.demo.servicea;
      import org.springframework.boot.SpringApplication;
      import org.springframework.boot.autoconfigure.SpringBootApplication;
      import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
      /**
       * 启动类
       *
       * @author XXX
       * @since 2023-12-05
       */
      @SpringBootApplication
      @EnableEurekaClient
      public class ServiceASpringbootApplication {
          public static void main(String[] args) {
              SpringApplication.run(ServiceASpringbootApplication.class, args);
          }
      }
      ```
      
   
   2. 编写Controller类
      ```
      package com.huawei.demo.servicea.controller;
      import org.springframework.beans.factory.annotation.Autowired;
      import org.springframework.web.bind.annotation.GetMapping;
      import org.springframework.web.bind.annotation.PathVariable;
      import org.springframework.web.bind.annotation.RequestMapping;
      import org.springframework.web.bind.annotation.RestController;
      import com.huawei.demo.servicea.pojo.UserInfo;
      import com.huawei.demo.servicea.service.UserService;
      /**
       * 用户对外接口
       *
       * @author XXX
       * @since 2023-12-06
       */
      @RestController
      @RequestMapping("/user")
      public class UserController {
          @Autowired
          private UserService userService;
          @GetMapping("/{userId}")
          public UserInfo getUserByName(@PathVariable String userId) {
              return userService.getUserById(userId);
          }
      }
      ```
      
   
   3. 编写Mapper类
      ```
      package com.huawei.demo.servicea.mapper;
      import org.apache.ibatis.annotations.Mapper;
      import org.apache.ibatis.annotations.Select;
      import com.huawei.demo.servicea.pojo.UserInfo;
      /**
       * 用户查询
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Mapper
      public interface UserMapper {
          @Select("select * from demo_user_info where user_id = #{userId}")
          UserInfo getUserById(String userId);
      }
      ```
      
   
   4. 编写Pojo类
      ```
      package com.huawei.demo.servicea.pojo;
      import lombok.Data;
      /**
       * user信息
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Data
      public class UserInfo {
          private String userId;
          private String userName;
          private String phone;
          private String address;
      }
      ```
      
   
   5. 编写Service类
      ```
      package com.huawei.demo.servicea.service;
      import org.springframework.beans.factory.annotation.Autowired;
      import org.springframework.stereotype.Service;
      import com.huawei.demo.servicea.mapper.UserMapper;
      import com.huawei.demo.servicea.pojo.UserInfo;
      /**
       * userService
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Service
      public class UserService {
          @Autowired
          private UserMapper userMapper;
          public UserInfo getUserById(String userId) {
              return userMapper.getUserById(userId);
          }
      }
      ```
      
   
   6. 配置微服务
      ```
      server:
        port: 8081
      spring:
        application:
          name: demoServiceA
        datasource:
          url: jdbc:mysql://127.0.0.1:3306/spring_cloud_demo?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
          username: root
          password: ***
          driver-class-name: com.mysql.jdbc.Driver
      mybatis:
        configuration:
          map-underscore-to-camel-case: true
        type-aliases-package: com.huawei.dmo.servicea
      ```
      
   
   
   
   
 
#### 创建子工程ServiceB
1. 创建Maven工程。 
   图5创建Maven工程   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001812717800.png)
   
   
2. 新建src目录。 
   图6新建src目录   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859437921.png)
   
   
3. 编写业务代码。 
   图7业务代码文件   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001812558028.png)
   1. 编写启动类
      ```
      package com.huawei.demo.serviceb;
      import org.springframework.boot.SpringApplication;
      import org.springframework.boot.autoconfigure.SpringBootApplication;
      import org.springframework.cloud.client.loadbalancer.LoadBalanced;
      import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
      import org.springframework.context.annotation.Bean;
      import org.springframework.web.client.RestTemplate;
      /**
       * 功能描述
       *
       * @author XXX
       * @since 2023-12-05
       */
      @SpringBootApplication
      @EnableEurekaClient
      public class ServiceBSpringbootApplication {
          public static void main(String[] args) {
              SpringApplication.run(ServiceBSpringbootApplication.class, args);
          }
          @Bean
          @LoadBalanced
          public RestTemplate restTemplate() {
              return new RestTemplate();
          }
      }
      ```
      
   
   2. 编写Controller类
      ```
      package com.huawei.demo.serviceb.controller;
      import org.springframework.beans.factory.annotation.Autowired;
      import org.springframework.web.bind.annotation.GetMapping;
      import org.springframework.web.bind.annotation.PathVariable;
      import org.springframework.web.bind.annotation.RequestMapping;
      import org.springframework.web.bind.annotation.RestController;
      import com.huawei.demo.serviceb.pojo.OrderInfo;
      import com.huawei.demo.serviceb.service.OrderService;
      /**
       * 用户对外接口
       *
       * @author XXX
       * @since 2023-12-06
       */
      @RestController
      @RequestMapping("/order")
      public class OrderController {
          @Autowired
          private OrderService orderService;
          @GetMapping("/{orderId}")
          public OrderInfo findOrder(@PathVariable String orderId) {
              return orderService.findOrder(orderId);
          }
      }
      ```
      
   
   3. 编写Domain类
      ```
      package com.huawei.demo.serviceb.domain;
      import lombok.Data;
      /**
       * user信息
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Data
      public class UserInfo {
          private String userId;
          private String userName;
          private String phone;
          private String address;
      }
      ```
      
   
   4. 编写Mapper类
      ```
      package com.huawei.demo.serviceb.mapper;
      import org.apache.ibatis.annotations.Mapper;
      import org.apache.ibatis.annotations.Select;
      import com.huawei.demo.serviceb.pojo.OrderInfo;
      /**
       * 用户查询
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Mapper
      public interface OrderMapper {
          @Select("select * from demo_order_info where order_id = #{orderId}")
          OrderInfo getOrderById(String orderId);
      }
      ```
      
   
   5. 编写Pojo类
      ```
      package com.huawei.demo.serviceb.pojo;
      import com.huawei.demo.serviceb.domain.UserInfo;
      import lombok.Data;
      /**
       * order信息
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Data
      public class OrderInfo {
          private String orderId;
          private String orderName;
          private String price;
          private String userId;
          private UserInfo userInfo;
      }
      ```
      
   
   6. 编写Service类
      ```
      package com.huawei.demo.serviceb.service;
      import org.springframework.beans.factory.annotation.Autowired;
      import org.springframework.stereotype.Service;
      import org.springframework.web.client.RestTemplate;
      import com.huawei.demo.serviceb.domain.UserInfo;
      import com.huawei.demo.serviceb.mapper.OrderMapper;
      import com.huawei.demo.serviceb.pojo.OrderInfo;
      /**
       * 功能描述
       *
       * @author XXX
       * @since 2023-12-06
       */
      @Service
      public class OrderService {
          @Autowired
          private RestTemplate restTemplate;
          @Autowired
          private OrderMapper orderMapper;
          public OrderInfo findOrder(String orderId) {
              OrderInfo orderInfo=orderMapper.getOrderById(orderId);
              String url = "http://demoServiceA/user/" + orderInfo.getUserId();
              UserInfo userInfo = restTemplate.getForObject(url, UserInfo.class);
              orderInfo.setUserInfo(userInfo);
              return orderInfo;
          }
      }
      ```
      
   
   7. 配置微服务
      ```
      server:
        port: 8082
      spring:
        application:
          name: demoServiceB
        datasource:
          url: jdbc:mysql://127.0.0.1:3306/spring_cloud_demo?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai
          username: root
          password: ***
          driver-class-name: com.mysql.jdbc.Driver
      eureka:
        client:
          service-url:
            defaultZone: http://localhost:11011/eureka/
      mybatis:
        configuration:
          map-underscore-to-camel-case: true
        type-aliases-package: com.huawei.dmo.servicea
      ```
      
   
   
   
   
#### 创建Eureka注册中心
1. 创建Eureka微服务。
2. 添加依赖。 
   ```
   <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
   </dependency>
   <dependency>
       <groupId>org.springframework.cloud</groupId>
       <artifactId>spring-cloud-starter-eureka-server</artifactId>
   </dependency>
   <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-web</artifactId>
   </dependency>
   ```
   
   
3. 新建启动类。 
   图8新建启动类   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001859455001.png)
   
   
4. 启动类中增加注解@EnableEurekaServer，标明注册中心微服务。 
   ```
   @SpringBootApplication
   @EnableEurekaServer
   public class EurekaSpringbootApplication {
       public static void main(String[] args) {
           SpringApplication.run(EurekaSpringbootApplication.class, args);
       }
   }
   ```
   
   
5. 在Eureka微服务中增加配置文件。 
   图9增加配置文件   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001812900714.png)
   
   
6. 配置注册中心微服务端口等。 
   ```
   server:
     port: 11011
   spring:
     application:
       name: eureka
   eureka:
     client:
       register-with-eureka: false
       fetch-registry: false
   ```
   
   
7. 其他微服务中增加注册中心配置。 
   ```
   eureka:
     client:
       service-url:
         defaultZone: http://localhost:11011/eureka/
   ```
   
   
8. 依次启动Eureka、DemoServiceA、DemoServiceB，访问http://localhost:11011/，可以看到DemoServiceA、DemoServiceB的信息。 
   图10查看微服务注册信息   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001812905310.png)
   
   
9. 调用接口：http://localhost:8082/order/1。 
   图11调用接口   
   ![](https://support.huaweicloud.com/devg-appstage/zh-cn_image_0000001812907626.png)