本文介绍如何将Maven和Mybatis-Generator配合使用。
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简介
Mybatis-Generator是Mybatis提供的一个便捷型插件，自动可以为项目生产对应的实体类，Mapper，dao层。
官网文档：http://www.mybatis.org/generator/index.html
入门案例
本文使用SpringBoot结合Mybatis-Generator插件使用，数据库Mysql。
新建项目
新建一个SpringBoot项目。
依赖文件
在项目pom文件中，引入Mybatis-Generator插件，并且引入Mybatis和Mysql依赖。完整pom代码如下：
<?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> <groupId>com.dalaoyang</groupId> <artifactId>springboot_generator</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>springboot_generator</name> <description>springboot_generator</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.5.15.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> <java.version>1.8</java.version> </properties> <dependencies> <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-web</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-devtools</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> </dependencies> <build> <plugins> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.2</version> <executions> <execution> <id>mybatis-generator</id> <phase>deploy</phase> <goals> <goal>generate</goal> </goals> </execution> </executions> <configuration> <!-- Mybatis-Generator 工具配置文件的位置 --> <configurationFile>src/main/resources/mybatis-generator/generatorConfig.xml</configurationFile> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> <dependencies> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>5.1.46</version> </dependency> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.2</version> </dependency> </dependencies> </plugin> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <configuration> <classifier>exec</classifier> </configuration> </plugin> </plugins> </build></project>
配置Mybatis-Generator配置
在pom文件中配置的Mybatis-Generator 工具配置文件的位置新建一个generatorConfig.xml，（本文案例配置的位置是src/main/resources/mybatis-generator/generatorConfig.xml），配置文件代码如下，具体配置需要自行修改至自己的项目：
<?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"><!-- 配置生成器 --><generatorConfiguration>
<!--执行generator插件生成文件的命令： call mvn mybatis-generator:generate -e -->
<!-- 引入配置文件 -->
<properties resource="application.properties"/>
<!--classPathEntry:数据库的JDBC驱动,换成你自己的驱动位置 可选 -->
<!--<classPathEntry location="D:generator_mybatismysql-connector-java-5.1.24-bin.jar" /> -->
<!-- 一个数据库一个context -->
<!--defaultModelType="flat" 大数据字段，不分表 -->
<context id="MysqlTables" targetRuntime="MyBatis3Simple" defaultModelType="flat">
<!-- 自动识别数据库关键字，默认false，如果设置为true，根据SqlReservedWords中定义的关键字列表；
一般保留默认值，遇到数据库关键字（Java关键字），使用columnOverride覆盖 -->
<property name="autoDelimitKeywords" value="true" />
<!-- 生成的Java文件的编码 -->
<property name="javaFileEncoding" value="utf-8" />
<!-- beginningDelimiter和endingDelimiter：指明数据库的用于标记数据库对象名的符号，比如ORACLE就是双引号，MYSQL默认是`反引号； -->
<property name="beginningDelimiter" value="`" />
<property name="endingDelimiter" value="`" />
<!-- 格式化java代码 -->
<property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>
<!-- 格式化XML代码 -->
<property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/>
<plugin type="org.mybatis.generator.plugins.SerializablePlugin" />
<plugin type="org.mybatis.generator.plugins.ToStringPlugin" />
<!-- 注释 -->
<commentGenerator >
<property name="suppressAllComments" value="false"/><!-- 是否取消注释 -->
<property name="suppressDate" value="true" /> <!-- 是否生成注释代时间戳-->
</commentGenerator>
<!-- jdbc连接 -->
<jdbcConnection driverClass="${spring.datasource.driver-class-name}" connectionURL="${spring.datasource.url}" userId="${spring.datasource.username}" password="${spring.datasource.password}" />
<!-- 类型转换 -->
<javaTypeResolver>
<!-- 是否使用bigDecimal， false可自动转化以下类型（Long, Integer, Short, etc.） -->
<property name="forceBigDecimals" value="false"/>
</javaTypeResolver>
<!-- 生成实体类地址 -->
<javaModelGenerator targetPackage="com.dalaoyang.entity" targetProject="${mybatis.project}" >
<property name="enableSubPackages" value="false"/>
<property name="trimStrings" value="true"/>
</javaModelGenerator>
<!-- 生成mapxml文件 -->
<sqlMapGenerator targetPackage="mapper" targetProject="${mybatis.resources}" >
<property name="enableSubPackages" value="false" />
</sqlMapGenerator>
<!-- 生成mapxml对应client，也就是接口dao -->
<javaClientGenerator targetPackage="com.dalaoyang.dao" targetProject="${mybatis.project}" type="XMLMAPPER" >
<property name="enableSubPackages" value="false" />
</javaClientGenerator>
<!-- table可以有多个,每个数据库中的表都可以写一个table，tableName表示要匹配的数据库表,也可以在tableName属性中通过使用%通配符来匹配所有数据库表,只有匹配的表才会自动生成文件 -->
<table tableName="user" enableCountByExample="true" enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true">
<property name="useActualColumnNames" value="false" />
<!-- 数据库表主键 -->
<generatedKey column="id" sqlStatement="Mysql" identity="true" />
</table>
<table tableName="book" enableCountByExample="true" enableUpdateByExample="true" enableDeleteByExample="true" enableSelectByExample="true" selectByExampleQueryId="true">
<property name="useActualColumnNames" value="false" />
<!-- 数据库表主键 -->
<generatedKey column="id" sqlStatement="Mysql" identity="true" />
</table>
</context></generatorConfiguration>配置application.properties
配置项目的application.properties，其中数据库信息，Mapper地址之前都有过介绍，具体SpringBoot-Mybatis配置可以参考：
《SpringBoot+Mybatis+MySql学习》
本文配置如下：
## mapper xml 文件地址mybatis.mapper-locations=classpath*:mapper/*Mapper.xml##数据库urlspring.datasource.url=jdbc:mysql://localhost:3306/test?characterEncoding=utf8&useSSL=false##数据库用户名spring.datasource.username=root##数据库密码spring.datasource.password=123456##数据库驱动spring.datasource.driver-class-name=com.mysql.jdbc.Driver#Mybatis Generator configuration#dao类和实体类的位置mybatis.project =src/main/java#mapper文件的位置mybatis.resources=src/main/resources
到这里其实配置就完成了，可以体验Mybatis-Generator插件的优点了，在右侧Maven处点击如图所示位置，如图：
image
点击完成后，可以看到Mapper，dao，实体类都已经创建好了，如图：
image
创建完成会给我生成几个默认的建当方法，如UserMapper代码如下：
package com.dalaoyang.dao;import com.dalaoyang.entity.User;import org.apache.ibatis.annotations.Mapper;import java.util.List;public interface UserMapper { /**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int deleteByPrimaryKey(Long id); /**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int insert(User record); /**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
User selectByPrimaryKey(Long id); /**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
List<User> selectAll(); /**
* This method was generated by MyBatis Generator.
* This method corresponds to the database table user
*
* @mbggenerated
*/
int updateByPrimaryKey(User record);
}UserMapper.xml代码如下：
<?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.dalaoyang.dao.UserMapper" >
<resultMap id="BaseResultMap" type="com.dalaoyang.entity.User" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
<id column="id" property="id" jdbcType="BIGINT" />
<result column="user_name" property="userName" jdbcType="VARCHAR" />
<result column="user_password" property="userPassword" jdbcType="VARCHAR" />
</resultMap>
<delete id="deleteByPrimaryKey" parameterType="java.lang.Long" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
delete from user
where id = #{id,jdbcType=BIGINT} </delete>
<insert id="insert" parameterType="com.dalaoyang.entity.User" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
<selectKey resultType="java.lang.Long" keyProperty="id" order="AFTER" >
SELECT LAST_INSERT_ID() </selectKey>
insert into user (user_name, user_password)
values (#{userName,jdbcType=VARCHAR}, #{userPassword,jdbcType=VARCHAR}) </insert>
<update id="updateByPrimaryKey" parameterType="com.dalaoyang.entity.User" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
update user
set user_name = #{userName,jdbcType=VARCHAR},
user_password = #{userPassword,jdbcType=VARCHAR}
where id = #{id,jdbcType=BIGINT} </update>
<select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
select id, user_name, user_password
from user
where id = #{id,jdbcType=BIGINT} </select>
<select id="selectAll" resultMap="BaseResultMap" >
<!--
WARNING - @mbggenerated
This element is automatically generated by MyBatis Generator, do not modify.
-->
select id, user_name, user_password
from user </select></mapper>
作者：dalaoyang
链接：https://www.jianshu.com/p/a8bfc14a3534
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