SpringCloud教学文章
第一篇:如何拆分微服务
简介:本文讲解如何如何利用SpringCloud进行微服务的拆分。
样例结构
cloud-demo:父工程,管理依赖
- order-service:订单微服务,负责订单相关业务
- user-service:用户微服务,负责用户相关业务
要求:
- 订单微服务和用户微服务都必须有各自的数据库,相互独立
- 订单服务和用户服务都对外暴露Restful的接口
- 订单服务如果需要查询用户信息,只能调用用户服务的Restful接口,不能查询用户数据库
数据库数据
- cloud-order.sql
-- ---------------------------- -- Table structure for tb_order -- ---------------------------- DROP TABLE IF EXISTS `tb_order`; CREATE TABLE `tb_order` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '订单id', `user_id` bigint(20) NOT NULL COMMENT '用户id', `name` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '商品名称', `price` bigint(20) NOT NULL COMMENT '商品价格', `num` int(10) NULL DEFAULT 0 COMMENT '商品数量', PRIMARY KEY (`id`) USING BTREE, UNIQUE INDEX `username`(`name`) USING BTREE ) ENGINE = InnoDB AUTO_INCREMENT = 109 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of tb_order -- ---------------------------- INSERT INTO `tb_order` VALUES (101, 1, 'Apple 苹果 iPhone 12 ', 699900, 1); INSERT INTO `tb_order` VALUES (102, 2, '雅迪 yadea 新国标电动车', 209900, 1); INSERT INTO `tb_order` VALUES (103, 3, '骆驼(CAMEL)休闲运动鞋女', 43900, 1); INSERT INTO `tb_order` VALUES (104, 4, '小米10 双模5G 骁龙865', 359900, 1); INSERT INTO `tb_order` VALUES (105, 5, 'OPPO Reno3 Pro 双模5G 视频双防抖', 299900, 1); INSERT INTO `tb_order` VALUES (106, 6, '美的(Midea) 新能效 冷静星II ', 544900, 1); INSERT INTO `tb_order` VALUES (107, 2, '西昊/SIHOO 人体工学电脑椅子', 79900, 1); INSERT INTO `tb_order` VALUES (108, 3, '梵班(FAMDBANN)休闲男鞋', 31900, 1);
- cloud-user.sql
-- ---------------------------- -- Table structure for tb_user -- ---------------------------- DROP TABLE IF EXISTS `tb_user`; CREATE TABLE `tb_user` ( `id` bigint(20) NOT NULL AUTO_INCREMENT, `username` varchar(100) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '收件人', `address` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '地址', PRIMARY KEY (`id`) USING BTREE, UNIQUE INDEX `username`(`username`) USING BTREE ) ENGINE = InnoDB AUTO_INCREMENT = 109 CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact; -- ---------------------------- -- Records of tb_user -- ---------------------------- INSERT INTO `tb_user` VALUES (1, '柳岩', '湖南省衡阳市'); INSERT INTO `tb_user` VALUES (2, '文二狗', '陕西省西安市'); INSERT INTO `tb_user` VALUES (3, '华沉鱼', '湖北省十堰市'); INSERT INTO `tb_user` VALUES (4, '张必沉', '天津市'); INSERT INTO `tb_user` VALUES (5, '郑爽爽', '辽宁省沈阳市大东区'); INSERT INTO `tb_user` VALUES (6, '范兵兵', '山东省青岛市');
后端配置
项目结构
父工程
- 文件结构
- pom.xml
这个父工程的pom.xml算是祖传的
<?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>cn.itcast.demo</groupId> <artifactId>cloud-demo</artifactId> <version>1.0</version> <modules> <module>user-service</module> <module>order-service</module> </modules> <packaging>pom</packaging> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.3.9.RELEASE</version> <relativePath/> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> <spring-cloud.version>Hoxton.SR10</spring-cloud.version> <mysql.version>5.1.47</mysql.version> <mybatis.version>2.1.1</mybatis.version> </properties> <dependencyManagement> <dependencies> <!-- springCloud --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> <!-- mysql驱动 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.version}</version> </dependency> <!--mybatis--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>${mybatis.version}</version> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> </dependency> </dependencies> </project>
子工程
order-service
- pom.xml
对于子工程要通过,<parent>来引入父工程的pom.xml
<?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>cloud-demo</artifactId> <groupId>cn.itcast.demo</groupId> <version>1.0</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>order-service</artifactId> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!--mybatis--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
- application.yml
server: port: 8080 spring: datasource: url: jdbc:mysql://localhost:3306/cloud_order?useSSL=false username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver mybatis: type-aliases-package: cn.itcast.user.pojo configuration: map-underscore-to-camel-case: true logging: level: cn.itcast: debug pattern: dateformat: MM-dd HH:mm:ss:SSS
- OrderApplication
@MapperScan("cn.itcast.order.mapper") @SpringBootApplication public class OrderApplication { public static void main(String[] args) { SpringApplication.run(OrderApplication.class, args); } }
- OrderMapper
public interface OrderMapper { @Select("select * from tb_order where id = #{id}") Order findById(Long id); }
- Order
@Data public class Order { private Long id; private Long price; private String name; private Integer num; private Long userId; private User user; }
- User
@Data public class User { private Long id; private String username; private String address; }
- OrderService
@Service public class OrderService { @Autowired private OrderMapper orderMapper; public Order queryOrderById(Long orderId) { // 1.查询订单 Order order = orderMapper.findById(orderId); // 4.返回 return order; } }
- OrderController
@RestController @RequestMapping("order/") public class OrderController { @Autowired private OrderService orderService; @GetMapping("{orderId}") public Order queryOrderByUserId(@PathVariable("orderId") Long orderId) { // 根据id查询订单并返回 return orderService.queryOrderById(orderId); } }
user-service
- 文件结构
- pom.xml
<?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>cloud-demo</artifactId> <groupId>cn.itcast.demo</groupId> <version>1.0</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>user-service</artifactId> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <!--mybatis--> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> </dependency> </dependencies> <build> <finalName>app</finalName> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>
- application.yml
server: port: 8081 spring: datasource: url: jdbc:mysql://localhost:3306/cloud_user?useSSL=false username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver mybatis: type-aliases-package: cn.itcast.user.pojo configuration: map-underscore-to-camel-case: true logging: level: cn.itcast: debug pattern: dateformat: MM-dd HH:mm:ss:SSS
- UserApplication
@MapperScan("cn.itcast.user.mapper") @SpringBootApplication public class UserApplication { public static void main(String[] args) { SpringApplication.run(UserApplication.class, args); } }
- UserMapper
public interface UserMapper { @Select("select * from tb_user where id = #{id}") User findById(@Param("id") Long id); }
- User
@Data public class User { private Long id; private String username; private String address; }
- UserService
@Service public class UserService { @Autowired private UserMapper userMapper; public User queryById(Long id) { return userMapper.findById(id); } }
- UserController
@Slf4j @RestController @RequestMapping("/user") public class UserController { @Autowired private UserService userService; /** * 路径: /user/110 * * @param id 用户id * @return 用户 */ @GetMapping("/{id}") public User queryById(@PathVariable("id") Long id) { return userService.queryById(id); } }
项目运行演示
在order-service服务中,有一个根据id查询订单的接口:
根据id查询订单,返回值是Order对象,如图:
其中的user为null
在user-service中有一个根据id查询用户的接口:
查询的结果如图:
案例需求
简介
修改order-service中的根据id查询订单业务,要求在查询订单的同时,根据订单中包含的userId查询出用户信息,一起返回。
因此,我们需要在order-service中 向user-service发起一个http的请求,调用http://localhost:8081/user/{userId}这个接口。
大概的步骤是这样的:
- 注册一个RestTemplate的实例到Spring容器
- 修改order-service服务中的OrderService类中的queryOrderById方法,根据Order对象中的userId查询User
- 将查询的User填充到Order对象,一起返回
注册RestTemplate
首先,我们在order-service服务中的OrderApplication启动类中,注册RestTemplate实例:
import org.mybatis.spring.annotation.MapperScan; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; import org.springframework.web.client.RestTemplate; @MapperScan("cn.itcast.order.mapper") @SpringBootApplication public class OrderApplication { public static void main(String[] args) { SpringApplication.run(OrderApplication.class, args); } @Bean public RestTemplate restTemplate() { return new RestTemplate(); } }
实现远程调用
修改order-service服务中的cn.itcast.order.service包下的OrderService类中的queryOrderById方法:
@Service public class OrderService { @Autowired private OrderMapper orderMapper; @Autowired private RestTemplate restTemplate; public Order queryOrderById(Long orderId) { // 1.查询订单 Order order = orderMapper.findById(orderId); // 2.远程查询user // 2.1 url地址 String url = "http://localhost:8081/user/" + order.getUserId(); // 2.2发起调用 User user = restTemplate.getForObject(url, User.class); // 3. 存入order order.setUser(user); // 4.返回 return order; } }
运行效果