使用 maven的 mybatis-generator 插件生成mapper文件

首先我们需要导入插件

1.pom文件中

<plugin>
   <groupId>org.mybatis.generator</groupId>
   <artifactId>mybatis-generator-maven-plugin</artifactId>
   <version>1.3.2</version>
   <configuration>
      <!-- mybatis用于生成代码的配置文件 -->
      <configurationFile>src/main/resources/generatorConfig.xml</configurationFile>
      <verbose>true</verbose>
      <overwrite>true</overwrite>
   </configuration>
   <dependencies>
      <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <version>5.1.38</version>
         <scope>runtime</scope>
      </dependency>
   </dependencies>
</plugin>

2.添加 generatorConfig.xml 配置文件

<?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>
     <!-- 引入外部的配置文件 用于引入属性-->
     <!--  例子 :  ${spring.datasource.driver-class-name} -->
     <properties resource="application-local.properties"></properties>
     <context id="mysql_tables" targetRuntime="MyBatis3">
        <!-- 防止生成的代码中有很多注释，加入下面的配置控制 true 不生成注释-->
        <commentGenerator>
            <property name="suppressAllComments" value="true" />
            <property name="suppressDate" value="true" />
        </commentGenerator>

        <!-- 数据库连接 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                        connectionURL="jdbc:mysql://localhost:3306/day20?serverTimezone=GMT%2B8&amp;characterEncoding=utf-8"
                        userId="root"
                        password="1234">
            <property name="nullCatalogMeansCurrent" value="true"/>
        </jdbcConnection>

        <javaTypeResolver >
            <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer， 为 true时把JDBC DECIMAL和NUMERIC类型解析为java.math.BigDecimal -->  
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!-- 数据表对应的model层  -->
        <javaModelGenerator targetPackage="com.asiainfo.bean" targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!-- sql mapper 映射配置文件 -->
        <sqlMapGenerator targetPackage="mapper"  targetProject="src/main/resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <!-- mybatis3中的mapper接口 -->
        <javaClientGenerator type="XMLMAPPER" targetPackage="com.asiainfo.dao" targetProject="src/main/java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <!-- 数据表进行生成操作 schema:相当于库名; tableName:表名; domainObjectName:对应的DO -->
        <!-- 要生成那些表(更改tableName和domainObjectName就可以) -->
         <table tableName="test2"
                domainObjectName = "testBean"
                enableCountByExample="false" enableUpdateByExample="false"
                enableDeleteByExample="false" enableSelectByExample="false"
                selectByExampleQueryId="false">
         </table>
     </context>
</generatorConfiguration>

3.运行maven命令

命令 : mybatis-generator:generate

4.如图运行成功