Spring Boot整合Mybatis

1、POM.xml依赖文件

<?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 http://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>2.1.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.smart</groupId>
    <artifactId>boot_mybatis</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>boot_mybatis</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-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.2</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>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2、创建实体类

package com.smart.boot_mybatis.domain;

public class User {
    private Long id;
    private String name;
    private int age;
    private String address;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

3、映射接口

package com.smart.boot_mybatis.mapper;

import com.smart.boot_mybatis.domain.User;

import java.util.List;

public interface UserMapper {

    int addUser(User user);

    int deleteUserById(Long id);

    int updateUserById(User user);

    User queryUserById(Long id);

    List<User> queryUserList();
}

4、对应的xml配置文件

<?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.smart.boot_mybatis.mapper.UserMapper">

    <resultMap id="BaseResultMap" type="com.smart.boot_mybatis.domain.User">
        <result column="t_id" property="id"/>
        <result column="t_name" property="name"/>
        <result column="t_age" property="age"/>
        <result column="t_address" property="address"/>
    </resultMap>

    <sql id="Base_Column_List">
        t_id,t_name,t_age,t_address
    </sql>

    <insert id="addUser"  parameterType="com.smart.boot_mybatis.domain.User">
        insert into t_user(t_id,t_name,t_age,t_address)
        values (#{id},#{name},#{age},#{address});
    </insert>

    <delete id="deleteUserById" parameterType="java.lang.Long">
        delete from t_user where t_id=#{id}
    </delete>

    <update id="updateUserById" parameterType="com.smart.boot_mybatis.domain.User">
        update t_user set
        <trim suffixOverrides=",">
            <if test="id !=null and id !=''">
                t_id=#{id},
            </if>
            <if test="name != null and name != ''">
                t_name=#{name},
            </if>
            <if test="age != null and age != ''">
                t_age=#{age},
            </if>
            <if test="address != null and address != ''">
                t_address=#{address},
            </if>
            where t_id=#{id};
        </trim>
    </update>

    <select id="queryUserById" resultMap="BaseResultMap" parameterType="java.lang.Long">
        select <include refid="Base_Column_List"/>
        from t_user where t_id=#{id}
    </select>

    <select id="queryUserList" resultMap="BaseResultMap">
        select <include refid="Base_Column_List"/>
        from t_user
    </select>
</mapper>

5、application.yml文件

spring:
  datasource:
     url: jdbc:mysql://127.0.0.1:3306/world?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
     driverClassName: com.mysql.cj.jdbc.Driver
     username: admin
     password: admin

mybatis:
     mapper-locations: classpath*:mybatis/mapper/*.xml

logging:
     level:
        com:
          smart:
             boot_mybatis:
                mapper: debug

6、访问控制器

package com.smart.boot_mybatis.controller;

import com.smart.boot_mybatis.domain.User;
import com.smart.boot_mybatis.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping(value="/user")
public class UserController {

    @Autowired
    UserMapper userMapper;

    @RequestMapping("/{userId}")
    public User getUserById(@PathVariable(value="userId") Long id){
        return userMapper.queryUserById(id);
    }
}

7、启动器

package com.smart.boot_mybatis;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.smart.boot_mybatis.mapper")
public class BootMybatisApplication {

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

}