springboot集成mybatis

springboot集成mybatis

pom文件

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.3.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.dtg</groupId>
    <artifactId>springmybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springmybatis</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-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.3</version>
        </dependency>
​
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
​
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
​
</project>

application.properties

server.port=8011
​
spring.datasource.username=root
spring.datasource.password=root
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
​
mybatis.mapper-locations=classpath:mapping/*Mapper.xml
mybatis.type-aliases-package=com.dtg.springmybatis.domain
​

 

创建工程包目录

domain

mapper

service

controller

数据库建表语句

​
CREATE TABLE `customer` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`customerName` varchar(128) NOT NULL DEFAULT '' COMMENT '客户名',
`mobile` varchar(32) NOT NULL DEFAULT '' COMMENT '客户手机',
`phone` varchar(32) NOT NULL DEFAULT '' COMMENT '客户电话',
`addr` varchar(256) NOT NULL COMMENT '地址',
`postCode` varchar(13) NOT NULL COMMENT '邮编',
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 COMMENT='客户表';
​

实体类Customer

package com.dtg.springmybatis.domain;
​
public class Customer {
    Integer id;
    String customerName;
    String phone;
    String mobile;
    String addr;
    String postCode;
​
    public Integer getId() {
        return id;
    }
​
    public void setId(Integer id) {
        this.id = id;
    }
​
    public String getCustomerName() {
        return customerName;
    }
​
    public void setCustomerName(String customerName) {
        this.customerName = customerName;
    }
​
    public String getPhone() {
        return phone;
    }
​
    public void setPhone(String phone) {
        this.phone = phone;
    }
​
    public String getMobile() {
        return mobile;
    }
​
    public void setMobile(String mobile) {
        this.mobile = mobile;
    }
​
    public String getAddr() {
        return addr;
    }
​
    public void setAddr(String addr) {
        this.addr = addr;
    }
​
    public String getPostCode() {
        return postCode;
    }
​
    public void setPostCode(String postCode) {
        this.postCode = postCode;
    }
}

 

Mapper接口类CustomerMapper

package com.dtg.springmybatis.mapper;
​
import com.dtg.springmybatis.domain.Customer;
​
import java.util.List;
​
public interface CustomerMapper {
    List <Customer> queryList();
    Customer queryCustomer(Integer id);
}

 

Mapper配置文件customerMapper.xml

1. resources下创建目录mapping

2. mapping目示下添加文件customerMapper.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.dtg.springmybatis.mapper.CustomerMapper">
   ​
       <!-- 可根据自己的需求，是否要使用 -->
       <resultMap type="Customer" id="CustomerResult">
           <id column="id" property="id" jdbcType="INTEGER" />
           <result column="customerName" property="customerName" jdbcType="VARCHAR" />
           <result column="phone" property="phone" jdbcType="VARCHAR" />
           <result column="mobile" property="mobile" jdbcType="VARCHAR" />
           <result column="addr" property="addr" jdbcType="VARCHAR" />
           <result column="postCode" property="postCode" jdbcType="VARCHAR" />
       </resultMap>
   ​
       <select id="queryCustomer" parameterType="INTEGER" resultMap="CustomerResult">
           select *
           from customer
           where 1=1
               and id = #{id,jdbcType=INTEGER}
       </select>
   ​
       <select id="queryList" parameterType="INTEGER" resultMap="CustomerResult">
           select *
           from customer
       </select>
   ​
   </mapper>

    

服务接口类CustomerService

package com.dtgtt.springbootmybatis.service;
​
import com.dtgtt.springbootmybatis.entity.Customer;
​
import java.util.List;
​
public interface CustomerService {
    List<Customer> list();
​
    Customer queryCustomer(Integer id);
}

 

服务实现类CustomerServiceImpl

package com.dtg.springmybatis.service.impl;
​
​
import com.dtg.springmybatis.domain.Customer;
import com.dtg.springmybatis.mapper.CustomerMapper;
import com.dtg.springmybatis.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
​
import java.util.List;
​
@Service
public class CustomerServiceImpl implements CustomerService {
​
    @Autowired
    CustomerMapper customerMapper;
​
    public List<Customer> list(){
        List<Customer> list = customerMapper.queryList();
        return list;
    }
​
    @Override
    public Customer queryCustomer(Integer id) {
        Customer c = customerMapper.queryCustomer(id);
        return c;
    }
}

 

业务控制层MainController

package com.dtg.springmybatis.controller;
​
import com.dtg.springmybatis.domain.Customer;
import com.dtg.springmybatis.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
​
import java.util.List;
​
@RestController
@RequestMapping("/main")
public class MainController {
​
​
    @Autowired
    CustomerService customerService;
​
    @RequestMapping("/list")
    public List<Customer> queryCustomerList(){
​
        List<Customer> list = customerService.list();
        return list;
    }
​
    @RequestMapping("/list")
    public Customer queryCustomer(@RequestParam("id") Integer id){
​
        Customer c  = customerService.queryCustomer(id);
        return c;
    }
​
​
}

springboot启动类增加@MapperScan注解

package com.dtg.springmybatis;
​
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
​
@SpringBootApplication
@MapperScan("com.dtg.springmybatis.mapper")
public class SpringmybatisApplication {
​
    public static void main(String[] args) {
        SpringApplication.run(SpringmybatisApplication.class, args);
    }
​
}
​

 

查询操作

http://localhost:8011/main/list3

http://localhost:8011/main/query?id=1

 

 

个人理解

mybatis 的使用主要涉及到mapper接口的定义（@MapperScan可扫描相关的接口）和mapper映射文件（mybatis.mapper-locations 指定了映射文件的位置）。

mapper接口提供了业务系统与mybatis交互的入口

mapper映射文件则提供了sql的编写配置方式。

mybatis内部会根据mapper接口的定义，找到相关的mapper映射xml文件，获取要查询的sql，然后对数据库进行操作，并将操作结果封装为mapper接口对应的返回值。