SpringBoot 整合mybatis+mybatis-plus的详细步骤

前言

在真实的项目开发中，使用SpringBoot可以说非常普遍了，而在框架整合中，与数据库的交互无外乎使用jpa,mybatis，mybatis-plus这几种，虽然hibernate仍然有在使用，毕竟框架毕竟重，而且用起来相较于mybatis还是差了那么点意思；

接下来演示下使用 SpringBoot 同时与mybatis，mybatis-plus的整合步骤；

准备工作

1、准备如下一个数据表

CREATE TABLE `student` (
 `id` varchar(32) NOT NULL,
 `gender` varchar(32) DEFAULT NULL,
 `age` int(12) DEFAULT NULL,
 `nick_name` varchar(32) DEFAULT NULL,
 `name` varchar(32) DEFAULT NULL,
 PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2、插入几条测试数据

整合步骤

工程的完整包结构如图所示

1、导入maven依赖

<parent>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-parent</artifactId>
       <version>2.1.1.RELEASE</version>
       <relativePath/> <!-- lookup parent from repository -->
   </parent>
   <properties>
       <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
       <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
       <java.version>1.8</java.version>
       <mysql-connector-java.version>8.0.11</mysql-connector-java.version>
       <commons-lang3.version>3.7</commons-lang3.version>
       <fastjson.version>1.2.47</fastjson.version>
       <mybatis-plus-boot-starter.version>3.3.0</mybatis-plus-boot-starter.version>
       <mybatis-plus-generator.version>3.3.0</mybatis-plus-generator.version>
       <druid.version>1.1.14</druid.version>
       <lombok.version>1.18.0</lombok.version>
       <dubbo-spring-boot-starter.version>2.0.0</dubbo-spring-boot-starter.version>
       <swagger.version>2.9.2</swagger.version>
       <swagger-bootstrap-ui.version>1.9.6</swagger-bootstrap-ui.version>
   </properties>

<dependencies>
       <dependency>
           <groupId>org.apache.commons</groupId>
           <artifactId>commons-lang3</artifactId>
           <version>3.4</version>
       </dependency>

<dependency>
           <groupId>org.springframework.boot</groupId>
           <artifactId>spring-boot-starter-web</artifactId>
       </dependency>

<!--mysql依赖-->
       <dependency>
           <groupId>mysql</groupId>
           <artifactId>mysql-connector-java</artifactId>
           <version>${mysql-connector-java.version}</version>
       </dependency>

<!--阿里巴巴fastjosn依赖-->
       <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>fastjson</artifactId>
           <version>${fastjson.version}</version>
       </dependency>

<!--阿里巴巴数据库连接池依赖-->
       <!-- Druid -->
       <dependency>
           <groupId>com.alibaba</groupId>
           <artifactId>druid-spring-boot-starter</artifactId>
           <version>${druid.version}</version>
       </dependency>

<dependency>
           <groupId>org.mybatis.spring.boot</groupId>
           <artifactId>mybatis-spring-boot-starter</artifactId>
           <version>2.1.1</version>
       </dependency>

<!-- MyBatis增强工具-->
       <dependency>
           <groupId>com.baomidou</groupId>
           <artifactId>mybatis-plus-boot-starter</artifactId>
           <version>${mybatis-plus-boot-starter.version}</version>
       </dependency>
       <dependency>
           <groupId>com.baomidou</groupId>
           <artifactId>mybatis-plus-generator</artifactId>
           <version>${mybatis-plus-generator.version}</version>
       </dependency>

<!-- lombok -->
       <dependency>
           <groupId>org.projectlombok</groupId>
           <artifactId>lombok</artifactId>
           <version>${lombok.version}</version>
       </dependency>

<!--swagger-ui-->
       <dependency>
           <groupId>io.springfox</groupId>
           <artifactId>springfox-swagger2</artifactId>
           <version>${swagger.version}</version>
       </dependency>

<dependency>
           <groupId>io.springfox</groupId>
           <artifactId>springfox-swagger-ui</artifactId>
           <version>${swagger.version}</version>
       </dependency>

<dependency>
           <groupId>com.github.xiaoymin</groupId>
           <artifactId>swagger-bootstrap-ui</artifactId>
           <version>${swagger-bootstrap-ui.version}</version>
       </dependency>

</dependencies>

2、配置文件 application.yml

server:
 port: 8083
logging:
 config: classpath:logback-spring.xml  #日志
spring:
 datasource:
   driver-class-name: com.mysql.cj.jdbc.Driver
   url: jdbc:mysql://IP:3306/school?autoReconnect=true&useUnicode=true&characterEncoding=utf8&serverTimezone=GMT％2B8&useSSL=false
   username: root
   password: root
   druid:
     max-active: 100
     initial-size: 10
     max-wait: 60000
     min-idle: 5
 #设置单个文件最大上传大小
 servlet:
   multipart:
     max-file-size: 20MB
mybatis-plus:
 mapper-locations: classpath*:mapper/*.xml
 global-config:
   db-column-underline: true  #开启驼峰转换
   db-config:
     id-type: uuid
     field-strategy: not_null
   refresh: true
 configuration:
   map-underscore-to-camel-case: true
   #log-impl: org.apache.ibatis.logging.stdout.StdOutImpl #打印sql语句便于调试

3、为了方便后面调试接口，增加一个swagger的配置

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;

/**
* swagger文档，项目启动后，浏览器访问:http://localhost:8083/swagger-ui.html
*/
@Configuration
@EnableSwagger2
public class ApiSwagger2 {

@Bean
   public Docket createRestBmbsApi() {
       return new Docket(DocumentationType.SWAGGER_2)
               .groupName("users")
               .apiInfo(apiInfo())
               .select()
               .apis(RequestHandlerSelectors.basePackage("com.congge.controller"))
               .paths(PathSelectors.any())
               .build();
   }

private ApiInfo apiInfo() {
       return new ApiInfoBuilder()
               .title("后端相关API")
               .version("1.0")
               .build();
   }

}

4、实体类

import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;

@Data
public class Student {

@TableField("id")
   private String id;

@TableField("name")
   private String name;

@TableField("gender")
   private String gender;

@TableField("age")
   private int age;

@TableField("nick_name")
   private String nickName;

}

5、dao接口，里面添加一个查询所有数据的方法

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.congge.entity.Student;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface StudentMapper extends BaseMapper<Student> {

List<Student> queryAll();

}

6、mybatis层，写sql的文件

<?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.congge.dao.StudentMapper">

<select id="queryAll" resultType="com.congge.entity.Student">
select * from student
</select>

</mapper>

7、业务实现类

在本次的业务实现中，同时可以使用mybatis的方式以及mybatis-plus的方式进行，具体使用的时候结合自身的需求进行选择；

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.congge.dao.StudentMapper;
import com.congge.entity.Student;
import com.congge.service.StudentService;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.List;

@Service
public class StudentServiceImpl implements StudentService {

@Resource
   private StudentMapper studentMapper;

@Override
   public List<Student> queryAllStudent() {
       QueryWrapper<Student> queryWrapper = new QueryWrapper();
       List<Student> students = studentMapper.selectList(queryWrapper);
       return students;
       //return studentMapper.queryAll();
   }

@Override
   public List<Student> getByName(String name) {
       QueryWrapper<Student> queryWrapper = new QueryWrapper();
       queryWrapper.like("name",name);
       return studentMapper.selectList(queryWrapper);
   }

public Student getById(String id) {
       QueryWrapper<Student> queryWrapper = new QueryWrapper();
       queryWrapper.like("id",id);
       return studentMapper.selectOne(queryWrapper);
   }
}

8、添加一个测试接口

@RestController
public class StudentController {

@Autowired
   private StudentService studentService;

@GetMapping("/getAll")
   public List<Student> getAll(){
       return studentService.queryAllStudent();
   }

@GetMapping("/getByName")
   public List<Student> getByName(@RequestParam String name){
       return studentService.getByName(name);
   }

@GetMapping("/getById")
   public Student getById(@RequestParam String id){
       return studentService.getById(id);
   }
}

9、启动类

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

@SpringBootApplication
public class App {

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

}

接下来，将工程运行起来做一下测试吧

10、启动之后，打开swagger界面

不妨随机测试两个接口吧，测试下获取所有学生的数据接口

本篇到这里基本上就结束了，更多的业务大家可以结合自身的实际情况，继续在代码中补充即可

来源：https://blog.csdn.net/congge_study/article/details/125433452