springboot2.1.7整合mybatis

1.先创建springboot项目，然后会有如下依赖（aop是自己加上去的）

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

2.然后添加mysql驱动包

<dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>5.1.46</version>
</dependency>

3.还要添加druid数据连接池（其他连接池也行，建议使用druid）

<dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid</artifactId>
   <version>1.0.9</version>
</dependency>

4.在application.properties配置文件中添加配置

#(默认端口号，可不配置)
server.port=8080

#连接mysql和连接池
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=root

#配置mysql数据库字段和实体属性映射
mybatis.configuration.map-underscore-to-camel-case=true

#添加sql日志（debug级别-level后面为你mapper接口的路径）
logging.level.com.example.mybatis.mapper=debug

#如果mapper.xml文件在resources下则需要此配置（classpath后面的mapper为存放xml文件的包）
mybatis.mapper-locations=classpath:mapper/*.xml

#如果Mapper的xml映射文件在src/main/java包下时，需要此配置
<resources>
   <resource>
      <directory>src/main/java</directory>
      <includes>
         <include>**/*.xml</include>
      </includes>
   </resource>
   <resource>
      <directory>src/main/resources</directory>
   </resource>
</resources>

5.配置完成之后，我们再添加一个mybatis-generator插件用来生成代码，我添加在了如下位置,

 打开generatorConfig.xml，如下:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <!--指定maven仓库中jdbc驱动jar包的位置-->
    <classPathEntry  location="E:\apache-maven-3.2.5\repository\mysql\mysql-connector-java\8.0.13\mysql-connector-java-8.0.13.jar"/>
    <!-- 一个数据库一个context -->
    <context id="DB2Tables"  targetRuntime="MyBatis3">
        <commentGenerator>
            <property name="suppressDate" value="true"/><!-- 是否生成注释代时间戳 -->
            <property name="suppressAllComments" value="true"/><!-- 是否去除自动生成的注释 true是 false:否 -->
        </commentGenerator>
        <!--数据库链接URL，用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://127.0.0.1/test?serverTimezone=GMT" userId="root" password="root">
            <property name="nullCatalogMeansCurrent" value="true" />
        </jdbcConnection>
        <!-- 类型转换 -->
        <javaTypeResolver>
        <!-- 默认false,把JDBC DECIMAL和NUMERIC类型解析为 Integer;为true时则解析为java.math.BigDecimal -->
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
        <!-- 生成model的包名和位置-->
        <javaModelGenerator targetPackage="com.example.mybatis.model" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
        <!-- 生成Mapper映射XML文件位置-->
        <sqlMapGenerator targetPackage="mapper" targetProject="src/main/resources">
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
        <!-- 生成Mapper接口文件位置-->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.example.mybatis.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="true"/>
        </javaClientGenerator>
        <!-- 要生成的表 tableName是数据库中的表名或视图名 domainObjectName是实体类名-->
        <table tableName="sys_permission" domainObjectName="Permission"
               enableCountByExample="true" enableUpdateByExample="true"
               enableDeleteByExample="true" enableSelectByExample="true"
               selectByExampleQueryId="true">
        </table>
    </context>
</generatorConfiguration>

6.在pom的plugins标签下添加插件依赖

<plugin>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-maven-plugin</artifactId>
　　#版本
   <version>1.3.2</version>
   <configuration>
　　　　此位置是上面截图的位置（你放在哪里就写在哪里）
      <configurationFile>D:\mybatis\src\main\resources\generate\generatorConfig.xml</configurationFile>
      <verbose>true</verbose>
      <overwrite>true</overwrite>
   </configuration>
   <executions>
      <execution>
         <id>Generate MyBatis Artifacts</id>
         <!--maven生成jar包时 避免运行generator插件（这个必须要加上，否则mapper接口和xml会在重新生成）-->
         <phase>deploy</phase>
         <goals>
            <goal>generate</goal>
         </goals>
      </execution>
   </executions>
   <dependencies>
      <dependency>
         <groupId>org.mybatis.generator</groupId>
         <artifactId>mybatis-generator-core</artifactId>
         <version>1.3.2</version>
      </dependency>
   </dependencies>
</plugin>

　7.双击图中白框部分，就会生成对应的文件