MyBatis Generator插件使用(配置详解)

迷南。 2022-04-14 21:17 622阅读 0赞

Hibernate 根据写好的 pojo启动服务器会自动帮助我们生成对应的数据表。

**Mybatis Generator简称 MBG**，是一个专门为 MyBatis和 ibatis框架使用者提供的代码生成器。也可以快速的根据数据表生成对应的pojo类、Mapper接口、Mapper文件，甚至生成QBC风格的查询对象。

一般在项目中，根据MyBatis Generator的XML配置文件设置生成简单的CRUD，但是复杂的查询或者有关关联的操作还是需要我们写SQL完成。

官方项目地址：[https://github.com/mybatis/generator][https_github.com_mybatis_generator]

官方文档地址：[http://www.mybatis.org/generator/][http_www.mybatis.org_generator]

**新建一个 maven web项目，pom.xml引出 mybatis-generator依赖**

<dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis</artifactId>
          <version>3.4.6</version>
        </dependency>
    
        
        <dependency>
          <groupId>org.mybatis.generator</groupId>
          <artifactId>mybatis-generator-core</artifactId>
          <version>1.3.7</version>
        </dependency>
    
        
        <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <version>5.1.46</version>
        </dependency>

### 一、使用 targetRuntime="MyBatis3Simple" 生成 ###

MyBatis3Simple：类似MyBatis3，只是不生成XXXBySample

**1、MBG 的配置文件，一般起名为 generatorConfig.xml：一般项目中使用这些就OK**

<?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>
    
        
        <context id="mysqlTables" targetRuntime="MyBatis3Simple">
    
            <commentGenerator>
                
                <property name="suppressAllComments" value="true"/>
            </commentGenerator>
    
            
            <jdbcConnection driverClass="com.mysql.jdbc.Driver"
                            connectionURL="jdbc:mysql://localhost:3306/mybatis_demo?useUnicode=true;characterEncoding=utf8;useSSL=true;serverTimezone=GMT"
                            userId="root"
                            password="123456">
            </jdbcConnection>
    
            
            <javaTypeResolver>
                
                <property name="forceBigDecimals" value="false"/>
            </javaTypeResolver>
    
            
            <javaModelGenerator targetPackage="cn.jq.jqmybatis.model" targetProject=".\src\main\java">
                
                <property name="enableSubPackages" value="true"/>
                
                <property name="trimStrings" value="true"/>
            </javaModelGenerator>
    
            
            <sqlMapGenerator targetPackage="cn.jq.jqmybatis.dao" targetProject=".\src\main\java">
                
                <property name="enableSubPackages" value="true"/>
            </sqlMapGenerator>
    
            
            <javaClientGenerator type="XMLMAPPER" targetPackage="cn.jq.jqmybatis.dao" targetProject=".\src\main\java">
                
                <property name="enableSubPackages" value="true"/>
            </javaClientGenerator>
    
            
            
            <table tableName="t_user" domainObjectName="User"></table>
            <table tableName="t_role" domainObjectName="Role"></table>
    
        </context>
    </generatorConfiguration>

**2、MBG启动类：使用 Java代码运行，也可使用 Maven插件运行**

固定写法，可参考官方文档：[http://www.mybatis.org/generator/running/runningWithJava.html][http_www.mybatis.org_generator_running_runningWithJava.html]

public class App {
    
        public static void main(String[] args) {
            try {
                App app = new App();
                app.generator();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    
        public  void generator() throws Exception{
            List<String> warnings = new ArrayList<String>();
            boolean overwrite = true;
            // 指定 逆向工程配置文件，这两种都可以
            String path = this.getClass().getClassLoader().getResource("generatorConfig.xml").getPath();
            File configFile = new File(path);
    //        File configFile = new File("D:/JDWorkspaceIDEA19/jqmybatis/src/main/resources/generatorConfig.xml");
    
            ConfigurationParser cp = new ConfigurationParser(warnings);
            Configuration config = cp.parseConfiguration(configFile);
            DefaultShellCallback callback = new DefaultShellCallback(overwrite);
            MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
            myBatisGenerator.generate(null);
        }
    
    }

**3、生成的文件**

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70][]

### 二、使用 targetRuntime="MyBatis3" 生成 ###

MyBatis3：默认的值，生成基于MyBatis3.x以上版本的内容，包括XXXBySample

把 MBG配置文件 那里改为 MyBatis3 即可，启动类一样，需要生成那张表，运行它即可

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70 2][]

<?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="cn.jq.jqmybatis.dao.UserMapper">
      <resultMap id="BaseResultMap" type="cn.jq.jqmybatis.model.User">
        <id column="id" jdbcType="BIGINT" property="id" />
        <result column="username" jdbcType="VARCHAR" property="username" />
        <result column="pazzword" jdbcType="VARCHAR" property="pazzword" />
        <result column="salary" jdbcType="DECIMAL" property="salary" />
        <result column="reg_date" jdbcType="TIMESTAMP" property="regDate" />
      </resultMap>
      <sql id="Example_Where_Clause">
        <where>
          <foreach collection="oredCriteria" item="criteria" separator="or">
            <if test="criteria.valid">
              <trim prefix="(" prefixOverrides="and" suffix=")">
                <foreach collection="criteria.criteria" item="criterion">
                  <choose>
                    <when test="criterion.noValue">
                      and ${criterion.condition}
                    </when>
                    <when test="criterion.singleValue">
                      and ${criterion.condition} #{criterion.value}
                    </when>
                    <when test="criterion.betweenValue">
                      and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                    </when>
                    <when test="criterion.listValue">
                      and ${criterion.condition}
                      <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
                        #{listItem}
                      </foreach>
                    </when>
                  </choose>
                </foreach>
              </trim>
            </if>
          </foreach>
        </where>
      </sql>
      <sql id="Update_By_Example_Where_Clause">
        <where>
          <foreach collection="example.oredCriteria" item="criteria" separator="or">
            <if test="criteria.valid">
              <trim prefix="(" prefixOverrides="and" suffix=")">
                <foreach collection="criteria.criteria" item="criterion">
                  <choose>
                    <when test="criterion.noValue">
                      and ${criterion.condition}
                    </when>
                    <when test="criterion.singleValue">
                      and ${criterion.condition} #{criterion.value}
                    </when>
                    <when test="criterion.betweenValue">
                      and ${criterion.condition} #{criterion.value} and #{criterion.secondValue}
                    </when>
                    <when test="criterion.listValue">
                      and ${criterion.condition}
                      <foreach close=")" collection="criterion.value" item="listItem" open="(" separator=",">
                        #{listItem}
                      </foreach>
                    </when>
                  </choose>
                </foreach>
              </trim>
            </if>
          </foreach>
        </where>
      </sql>
      <sql id="Base_Column_List">
        id, username, pazzword, salary, reg_date
      </sql>
      <select id="selectByExample" parameterType="cn.jq.jqmybatis.model.UserExample" resultMap="BaseResultMap">
        select
        <if test="distinct">
          distinct
        </if>
        <include refid="Base_Column_List" />
        from t_user
        <if test="_parameter != null">
          <include refid="Example_Where_Clause" />
        </if>
        <if test="orderByClause != null">
          order by ${orderByClause}
        </if>
      </select>
      <select id="selectByPrimaryKey" parameterType="java.lang.Long" resultMap="BaseResultMap">
        select 
        <include refid="Base_Column_List" />
        from t_user
        where id = #{id,jdbcType=BIGINT}
      </select>
      <delete id="deleteByPrimaryKey" parameterType="java.lang.Long">
        delete from t_user
        where id = #{id,jdbcType=BIGINT}
      </delete>
      <delete id="deleteByExample" parameterType="cn.jq.jqmybatis.model.UserExample">
        delete from t_user
        <if test="_parameter != null">
          <include refid="Example_Where_Clause" />
        </if>
      </delete>
      <insert id="insert" parameterType="cn.jq.jqmybatis.model.User">
        insert into t_user (id, username, pazzword, 
          salary, reg_date)
        values (#{id,jdbcType=BIGINT}, #{username,jdbcType=VARCHAR}, #{pazzword,jdbcType=VARCHAR}, 
          #{salary,jdbcType=DECIMAL}, #{regDate,jdbcType=TIMESTAMP})
      </insert>
      <insert id="insertSelective" parameterType="cn.jq.jqmybatis.model.User">
        insert into t_user
        <trim prefix="(" suffix=")" suffixOverrides=",">
          <if test="id != null">
            id,
          </if>
          <if test="username != null">
            username,
          </if>
          <if test="pazzword != null">
            pazzword,
          </if>
          <if test="salary != null">
            salary,
          </if>
          <if test="regDate != null">
            reg_date,
          </if>
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
          <if test="id != null">
            #{id,jdbcType=BIGINT},
          </if>
          <if test="username != null">
            #{username,jdbcType=VARCHAR},
          </if>
          <if test="pazzword != null">
            #{pazzword,jdbcType=VARCHAR},
          </if>
          <if test="salary != null">
            #{salary,jdbcType=DECIMAL},
          </if>
          <if test="regDate != null">
            #{regDate,jdbcType=TIMESTAMP},
          </if>
        </trim>
      </insert>
      <select id="countByExample" parameterType="cn.jq.jqmybatis.model.UserExample" resultType="java.lang.Long">
        select count(*) from t_user
        <if test="_parameter != null">
          <include refid="Example_Where_Clause" />
        </if>
      </select>
      <update id="updateByExampleSelective" parameterType="map">
        update t_user
        <set>
          <if test="record.id != null">
            id = #{record.id,jdbcType=BIGINT},
          </if>
          <if test="record.username != null">
            username = #{record.username,jdbcType=VARCHAR},
          </if>
          <if test="record.pazzword != null">
            pazzword = #{record.pazzword,jdbcType=VARCHAR},
          </if>
          <if test="record.salary != null">
            salary = #{record.salary,jdbcType=DECIMAL},
          </if>
          <if test="record.regDate != null">
            reg_date = #{record.regDate,jdbcType=TIMESTAMP},
          </if>
        </set>
        <if test="_parameter != null">
          <include refid="Update_By_Example_Where_Clause" />
        </if>
      </update>
      <update id="updateByExample" parameterType="map">
        update t_user
        set id = #{record.id,jdbcType=BIGINT},
          username = #{record.username,jdbcType=VARCHAR},
          pazzword = #{record.pazzword,jdbcType=VARCHAR},
          salary = #{record.salary,jdbcType=DECIMAL},
          reg_date = #{record.regDate,jdbcType=TIMESTAMP}
        <if test="_parameter != null">
          <include refid="Update_By_Example_Where_Clause" />
        </if>
      </update>
      <update id="updateByPrimaryKeySelective" parameterType="cn.jq.jqmybatis.model.User">
        update t_user
        <set>
          <if test="username != null">
            username = #{username,jdbcType=VARCHAR},
          </if>
          <if test="pazzword != null">
            pazzword = #{pazzword,jdbcType=VARCHAR},
          </if>
          <if test="salary != null">
            salary = #{salary,jdbcType=DECIMAL},
          </if>
          <if test="regDate != null">
            reg_date = #{regDate,jdbcType=TIMESTAMP},
          </if>
        </set>
        where id = #{id,jdbcType=BIGINT}
      </update>
      <update id="updateByPrimaryKey" parameterType="cn.jq.jqmybatis.model.User">
        update t_user
        set username = #{username,jdbcType=VARCHAR},
          pazzword = #{pazzword,jdbcType=VARCHAR},
          salary = #{salary,jdbcType=DECIMAL},
          reg_date = #{regDate,jdbcType=TIMESTAMP}
        where id = #{id,jdbcType=BIGINT}
      </update>
    </mapper>

上面截图和生成的Mapper映射文件，主要看一下它的书写很规范，可多多参考规范。

### 三、Mybatis Generator最完整配置详解 ###

转自：[https://blog.csdn.net/xiao\_jun\_0820/article/details/50402299][https_blog.csdn.net_xiao_jun_0820_article_details_50402299]

推荐参考文章：[MyBatis Generator 详解][MyBatis Generator]

配置文件信息可参考，项目中有需要的可作调整

<?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>
    
     
     
     
    
    <context id="mysql" defaultModelType="hierarchical" targetRuntime="MyBatis3Simple" >
     
        
        <property name="autoDelimitKeywords" value="false"/>
        
        <property name="javaFileEncoding" value="UTF-8"/>
        
        <property name="javaFormatter" value="org.mybatis.generator.api.dom.DefaultJavaFormatter"/>
        
        <property name="xmlFormatter" value="org.mybatis.generator.api.dom.DefaultXmlFormatter"/>
     
        
        <property name="beginningDelimiter" value="`"/>
        <property name="endingDelimiter" value="`"/>
     
        
        <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql:///pss" userId="root" password="admin">
            
        </jdbcConnection>
     
        
        <javaTypeResolver type="org.mybatis.generator.internal.types.JavaTypeResolverDefaultImpl">
            
            <property name="forceBigDecimals" value="false"/>
        </javaTypeResolver>
     
     
        
        <javaModelGenerator targetPackage="com._520it.mybatis.domain" targetProject="src/main/java">
            
            <property name="constructorBased" value="false"/>
     
            
            <property name="enableSubPackages" value="true"/>
     
            
            <property name="immutable" value="false"/>
     
            
            <property name="rootClass" value="com._520it.mybatis.domain.BaseDomain"/>
     
            
            <property name="trimStrings" value="true"/>
        </javaModelGenerator>
     
     
        
        <sqlMapGenerator targetPackage="com._520it.mybatis.mapper" targetProject="src/main/resources">
            
            <property name="enableSubPackages" value="true"/>
        </sqlMapGenerator>
     
     
        
        <javaClientGenerator targetPackage="com._520it.mybatis.mapper" type="ANNOTATEDMAPPER" targetProject="src/main/java">
            
            <property name="enableSubPackages" value="true"/>
     
            
        </javaClientGenerator>
     
        
        <table tableName="userinfo" >
     
            
            <property name="constructorBased" value="false"/>
     
            
            <property name="ignoreQualifiersAtRuntime" value="false"/>
     
            
            <property name="immutable" value="false"/>
     
            
            <property name="modelOnly" value="false"/>
     
            
     
            
     
            
     
            
     
            
     
            
            <property name="selectAllOrderByClause" value="age desc,username asc"/>
     
            
            <property name="useActualColumnNames" value="false"/>
     
     
            
     
            
     
     
             
             <columnOverride column="username">
                 
                 <property name="property" value="userName"/>
     
                 
     
                 
     
                 
     
                 
             </columnOverride>
     
             
        </table>
     
    </context>
     
    </generatorConfiguration>

会使用就ok

ends ~

[https_github.com_mybatis_generator]: https://github.com/mybatis/generator
[http_www.mybatis.org_generator]: http://www.mybatis.org/generator/
[http_www.mybatis.org_generator_running_runningWithJava.html]: http://www.mybatis.org/generator/running/runningWithJava.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70]: /images/20220415/25cbe1cf687340e19c844f9dc56d41ff.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70 1]: /images/20220415/c3ba48db0c2342dbb449da60de579c68.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQyNDAyODU0_size_16_color_FFFFFF_t_70 2]: /images/20220415/822b12dfab6d4ee39d3c63e795bcd882.png
[https_blog.csdn.net_xiao_jun_0820_article_details_50402299]: https://blog.csdn.net/xiao_jun_0820/article/details/50402299
[MyBatis Generator]: https://blog.csdn.net/isea533/article/details/42102297