创建微服务项目(入门)

一 、创建父项目

 点击Create

删掉其他的文件，留下pom.xml 

 

删掉配置

 

 二、创建子项目user-service

 点击create

 同样方式创建子项目book-service和borrow-service

 

三、在子项目中创建springboot的启动主类 

 

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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

 四、创建配置文件

 

 如果没有Maven Source Directory选项可以在创建好的resource右击→Mark Directory as→Resources Root

 在三个子模块新建application.yml

配置端口

三个服务三个不同的端口

server:
  port: 8081

五、启动三个子项目

右下角出现提示点击Use Service

 

 

启动全部 

 六、添加依赖（pom.xml）

子项目中

        
            org.springframework.boot
            spring-boot-starter-web
        

 父项目中

        
            org.projectlombok
            lombok
            1.18.24
        

        
            mysql
            mysql-connector-java
            8.0.28
        

添加完之后刷新maven

七、重新启动项目

点击enable annotation processing

启动成功后会显示刚刚配置的端口

 

八、创建数据库

db_user

CREATE TABLE `db_user` (
  `uid` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(255) COLLATE utf8mb4_unicode_520_ci NOT NULL,
  `age` int(11) NOT NULL,
  `sex` enum('男','女') COLLATE utf8mb4_unicode_520_ci NOT NULL,
  PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;

db_book

CREATE TABLE `db_book` (
  `bid` int(11) NOT NULL AUTO_INCREMENT,
  `title` varchar(255) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  `desc` varchar(255) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  PRIMARY KEY (`bid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;

db_borrow

CREATE TABLE `db_borrow` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `uid` int(11) DEFAULT NULL,
  `bid` int(11) DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `unique_bid_uid` (`uid`,`bid`),
  KEY `f_bid` (`bid`),
  CONSTRAINT `f_bid` FOREIGN KEY (`bid`) REFERENCES `db_book` (`bid`),
  CONSTRAINT `f_uid` FOREIGN KEY (`uid`) REFERENCES `db_user` (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;

自己造一些数据

九、父项目中引入依赖

    
    
        
            
                org.mybatis.spring.boot
                mybatis-spring-boot-starter
                2.2.2
            
        
    

子项目中

        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
        

数据库配置

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/数据库?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=GMT%2b8
    username: root
    password: root

 十、用户查询

user-service结构如下 

 User

@Data
public class User {
    int uid;
    String name;
    String sex;
    String age;
}

 UserController

@RestController
public class UserController {
    @Resource
    UserService userService;

    @RequestMapping("/user/{uid}")
    public User findUserById(@PathVariable("uid") int uid){
        return userService.getUserById(uid);
    }
}

UserService

public interface UserService {
    User getUserById(int uid);
}

UserServiceImpl

@Service
public class UserServiceImpl implements UserService {

    @Resource
    UserMapper userMapper;

    @Override
    public User getUserById(int uid) {
        return userMapper.getUserById(uid);
    }
}

UserMapper

@Mapper
public interface UserMapper {
    @Select("select  * from db_user where uid = #{uid}")
    User getUserById(int uid);
}

启动user-service

浏览器访问 http://localhost:8081/user/1

 成功

这里省略其book-service，一样的写法

十一、borrow-service服务

1、创建一个commons模块用于管理实体类

2、在commons模块创建entity，将book和user实体类放入，删掉book-service和user-service的entiy

3、在book-service、user-service、borrow-service的pom导入commons依赖

        
            com.example
            commons
            0.0.1-SNAPSHOT
        

4、borrow-service代码

创建UserBorrowDetail实体类

@Data
@AllArgsConstructor
public class UserBorrowDetail {
    User user;
    List bookList;
}

BorrowMapper

@Mapper
public interface BorrowMapper {

    @Select("select * from db_borrow where uid = #{uid};")
    List getBorrowByUid(int uid);
    @Select("select * from db_borrow where bid = #{bid};")
    List getBorrowByBid(int bid);
    @Select("select * from db_borrow where bid =#{bid} and uid = #{uid}")
    Borrow getBorrow(int uid,int bid);
}

BorrowService

public interface BorrowService {
    UserBorrowDetail getUserBorrowDetailByUid(int uid);
}

BorrowServiceImpl

拿到借阅关联信息，调用其他服务

@Service
public class BorrowServiceImpl implements BorrowService {
    @Resource
    BorrowMapper borrowMapper;

    @Override
    public UserBorrowDetail getUserBorrowDetailByUid(int uid) {
        List borrows = borrowMapper.getBorrowByUid(uid);
        //RestTemplate支持多种方式远程调用
        RestTemplate template = new RestTemplate();
        //调用getForObject请求其他服务，将结果自动进行封装
        User user = template.getForObject("http://localhost:8081/user/" + uid, User.class);

        List bookList = borrows
                .stream()
                .map(b -> template.getForObject("http://localhost:8082/book/" + b.getBid(),Book.class))
                .collect(Collectors.toList());
        return new UserBorrowDetail(user,bookList);
    }
}

BorrowController

@RestController
public class BorrowController {
    @Resource
    BorrowService borrowService;

    @RequestMapping("/borrow/{uid}")
    UserBorrowDetail findUserBorrows(@PathVariable("uid") int uid){
        return borrowService.getUserBorrowDetailByUid(uid);
    }
}

 同时运行三个服务访问 http://localhost:8083/borrow/1

调用成功

此入门项目是我向b站青空の霞光学习的项目，仅用做学习使用，具体微服务知识体系可前去学习