文档：http://mybatis.org/generator/index.html
依赖 pom.xml
<?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.mouday</groupId> <artifactId>generator-demo</artifactId> <version>1.0-SNAPSHOT</version> <build> <plugins> <plugin> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-maven-plugin</artifactId> <version>1.3.5</version> <configuration> <configurationFile>src/main/resources/generatorConfig.xml</configurationFile> <verbose>true</verbose> <overwrite>true</overwrite> </configuration> <dependencies> <dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.5</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.20</version> </dependency> </dependencies> </plugin> </plugins> </build> </project>
生成器配置 generatorConfig.xml
<?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> <context id="default" targetRuntime="MyBatis3"> <!-- jdbc的数据库连接 --> <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/data" userId="root" password="123456"/> <!-- Model模型生成器--> <javaModelGenerator targetPackage="com.mouday.demo.model" targetProject="src/main/java"/> <!-- Mapper映射文件--> <sqlMapGenerator targetPackage="com.mouday.demo.mapper" targetProject="src/main/java"/> <!-- Mapper接口--> <javaClientGenerator targetPackage="com.mouday.demo.mapper" targetProject="src/main/java" type="XMLMAPPER"/> <table tableName="person"/> </context> </generatorConfiguration>
参数说明
通用参数 targetPackage 指定包名 targetProject 指定路径 javaClientGenerator可选参数： type="ANNOTATEDMAPPER",生成Java Model 和基于注解的Mapper对象 type="MIXEDMAPPER",生成基于注解的Java Model 和相应的Mapper对象 type="XMLMAPPER",生成SQLMap XML文件和独立的Mapper接口
# 执行代码生成 $ mvn mybatis-generator:generate # 生成的文件 $ tree . ├── mapper │ ├── PersonMapper.java │ └── PersonMapper.xml └── model ├── Person.java └── PersonExample.java
查看生成的文件里边有很多无用的代码，可以通过进一步的配置来控制代码生成
<?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> <context id="default" targetRuntime="MyBatis3"> <!--创建class时，对注释进行控制--> <commentGenerator> <property name="suppressDate" value="true"/> <!--注释掉这行可以解决生成重复xml代码--> <property name="suppressAllComments" value="true"/> <property name="javaFileEncoding" value="UTF-8"/> </commentGenerator> <!-- jdbc的数据库连接 --> <jdbcConnection driverClass="com.mysql.cj.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/data" userId="root" password="123456"> </jdbcConnection> <!-- 非必需，类型处理器，在数据库类型和java类型之间的转换控制 --> <javaTypeResolver> <!-- 是否使用BigDecimals，false可自动转化以下类型(Long Integer Short等) --> <property name="forceBigDecimals" value="false"/> </javaTypeResolver> <!-- Model模型生成器--> <javaModelGenerator targetPackage="com.mouday.demo.model" targetProject="src/main/java"> <!--是否允许子包，即targetPackage.schemaName.tableName--> <property name="enableSubPackages" value="true"/> <!-- 是否对类CHAR类型的列的数据进行trim操作 --> <property name="trimStrings" value="true"/> </javaModelGenerator> <!-- Mapper映射文件--> <sqlMapGenerator targetPackage="com.mouday.demo.mapper" targetProject="src/main/java"> <property name="enableSubPackages" value="true"/> </sqlMapGenerator> <!-- Mapper接口--> <javaClientGenerator type="XMLMAPPER" targetPackage="com.mouday.demo.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="person" domainObjectName="Person" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"> </table> </context> </generatorConfiguration>
生成的代码就简洁了不少
Person.java
package com.mouday.demo.model; public class Person { private Integer id; private String name; private Integer age; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name == null ? null : name.trim(); } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } }
PersonMapper.java
package com.mouday.demo.mapper; import com.mouday.demo.model.Person; public interface PersonMapper { int deleteByPrimaryKey(Integer id); int insert(Person record); int insertSelective(Person record); Person selectByPrimaryKey(Integer id); int updateByPrimaryKeySelective(Person record); int updateByPrimaryKey(Person record); }
PersonMapper.xml
<?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.mouday.demo.mapper.PersonMapper"> <resultMap id="BaseResultMap" type="com.mouday.demo.model.Person"> <id column="id" jdbcType="INTEGER" property="id" /> <result column="name" jdbcType="VARCHAR" property="name" /> <result column="age" jdbcType="INTEGER" property="age" /> </resultMap> <sql id="Base_Column_List"> id, name, age </sql> <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap"> select <include refid="Base_Column_List" /> from person where id = #{id,jdbcType=INTEGER} </select> <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer"> delete from person where id = #{id,jdbcType=INTEGER} </delete> <insert id="insert" parameterType="com.mouday.demo.model.Person"> insert into person (id, name, age ) values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{age,jdbcType=INTEGER} ) </insert> <insert id="insertSelective" parameterType="com.mouday.demo.model.Person"> insert into person <trim prefix="(" suffix=")" suffixOverrides=","> <if test="id != null"> id, </if> <if test="name != null"> name, </if> <if test="age != null"> age, </if> </trim> <trim prefix="values (" suffix=")" suffixOverrides=","> <if test="id != null"> #{id,jdbcType=INTEGER}, </if> <if test="name != null"> #{name,jdbcType=VARCHAR}, </if> <if test="age != null"> #{age,jdbcType=INTEGER}, </if> </trim> </insert> <update id="updateByPrimaryKeySelective" parameterType="com.mouday.demo.model.Person"> update person <set> <if test="name != null"> name = #{name,jdbcType=VARCHAR}, </if> <if test="age != null"> age = #{age,jdbcType=INTEGER}, </if> </set> where id = #{id,jdbcType=INTEGER} </update> <update id="updateByPrimaryKey" parameterType="com.mouday.demo.model.Person"> update person set name = #{name,jdbcType=VARCHAR}, age = #{age,jdbcType=INTEGER} where id = #{id,jdbcType=INTEGER} </update> </mapper>
