Spring Boot整合Mybatis

时间 2020-03-22

原文原文链接

一、引入依赖

<!--引入mybatis-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.2</version>
</dependency>
<!--引入mysql驱动-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<!-- alibaba的druid数据库链接池 -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.10</version>
</dependency>
<!--引入lombok-->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.16.10</version>
</dependency>

能够看到mybatis的starter中导入了spring-boot-starter-jdbc，所以这里不须要再次导入jdbc依赖
css

二、配置application.yml文件

2.一、配置数据源

spring:
  # 配置数据源
  datasource:
    # 数据库url
    url: jdbc:mysql://127.0.0.1:3306/test?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=true
    # 用户名
    username: root
    # 密码
    password: root
    # 驱动类
    driver-class-name: com.mysql.cj.jdbc.Driver
    # 配置数据源类型，这里选择druid
    type: com.alibaba.druid.pool.DruidDataSource
    # druid相关配置
    druid:
      #初始化大小
      initialSize: 5
      #最小值
      minIdle: 5
      #最大值
      maxActive: 20
      #最大等待时间，配置获取链接等待超时，时间单位都是毫秒ms
      maxWait: 60000
      #配置间隔多久才进行一次检测，检测须要关闭的空闲链接
      timeBetweenEvictionRunsMillis: 60000
      #配置一个链接在池中最小生存的时间
      minEvictableIdleTimeMillis: 300000
      validationQuery: SELECT 1 FROM DUAL
      testWhileIdle: true
      testOnBorrow: false
      testOnReturn: false
      poolPreparedStatements: true
      # 配置监控统计拦截的filters，去掉后监控界面sql没法统计，
      #'wall'用于防火墙，SpringBoot中没有log4j，我改为了log4j2
      filters: stat,wall,log4j2
      #最大PSCache链接
      maxPoolPreparedStatementPerConnectionSize: 20
      useGlobalDataSourceStat: true
      # 经过connectProperties属性来打开mergeSql功能；慢SQL记录
      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500
      # 配置StatFilter
      web-stat-filter:
        #默认为false，设置为true启动
        enabled: true
        url-pattern: "/*"
        exclusions: "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*"
      #配置StatViewServlet
      stat-view-servlet:
        url-pattern: "/druid/*"
        #容许那些ip
        allow: 127.0.0.1
        login-username: admin
        login-password: 123456
        # 禁止那些ip
        deny: 192.168.1.102
        #是否能够重置
        reset-enable: true
        #启用
        enabled: true

2.二、创建JavaBean

package com.cheng.cache.pojo;

import lombok.Getter;
import lombok.Setter;

/**
 * @author cheng
 * @version 1.0
 * @date 2020/3/21
 */
@Getter
@Setter
public class Student
{
    private Integer id;

    private String name;

    private Integer age;
}

2.三、注解版Mybatis的使用

配置application.yml文件（能够不用配置）

# 配置mybatis
mybatis:
  # pojo类所在路劲
  type-aliases-package: com.cheng.cache.pojo
  configuration:
    # 配置项：开启下划线到驼峰的自动转换. 做用：将数据库字段根据驼峰规则自动注入到对象属性。
    map-underscore-to-camel-case: true

给启动类添加注解，扫描Mapper

@MapperScan("com.cheng.cache.mapper")

编写Mapper接口

public interface StudentMapper
{
    @Options(useGeneratedKeys = true, keyProperty = "id")
    @Insert("insert into student(name, age) values(#{name}, #{age})")
    public int insert(Student student);

    @Delete("delete from student where id = #{id}")
    public int delete(Integer id);

    @Select("select * from student where id = #{id}")
    public Student select(Integer id);

    @Update("update student set name = #{name},age = #{age} where id = #{id}")
    public int update(Student student);
}

配置版Mybatis的使用

配置yml文件

# 配置mybatis
mybatis:
  # 映射文件所在路径
  mapper-locations: classpath:mybatis/mapper/*.xml
  # pojo类所在路径
  type-aliases-package: com.cheng.cache.pojo
  configuration:
    #配置项：开启下划线到驼峰的自动转换. 做用：将数据库字段根据驼峰规则自动注入到对象属性。
    map-underscore-to-camel-case: true

编写xml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.cheng.cache.xmlmapper.XmlStudentMapper">

    <!--resultMap是Mybatis最强大的元素，它能够将查询到的复杂数据（好比查询到几个表中数据）映射到一个结果集当中-->
    <resultMap id="baseMap" type="com.cheng.cache.pojo.Student">
        <!--column不作限制，能够为任意表的字段，而property须为type 定义的pojo属性-->
        <id column="id" property="id" jdbcType="INTEGER"></id>
        <result column="name" property="name" jdbcType="VARCHAR"></result>
        <result column="age" property="age" jdbcType="INTEGER"></result>
    </resultMap>

    <!--public Student select(Integer id);-->
    <select id="select" parameterType="java.lang.Integer" resultMap="baseMap">
        select *
        from student
        where id = #{id}
    </select>

    <!--public int insert(Student student);-->
    <insert id="insert" parameterType="com.cheng.cache.pojo.Student" useGeneratedKeys="true" keyProperty="id">
        insert into student(name, age)
        values(#{name}, #{age})
    </insert>

    <!--public int delete(Integer id);-->
    <delete id="delete" parameterType="java.lang.Integer">
        delete from student
        where id = #{id}
    </delete>

    <!--public int update(Student student);-->
    <update id="update" parameterType="com.cheng.cache.pojo.Student">
        update student
        set name = #{name}, age=#{age}
        where id = #{id}
    </update>

</mapper>