MyBatisGenerator数据层代码生成器使用教程

一、MyBatis Generator简介

MyBatis Generator（MBG）是一个代码生成器，能够基于数据库表（一或多张表）生成用于访问表的构件，
例如：实体类、mapper接口、mapper.xml等。

二、MyBatis Generator的配置流程

1、pom.xml中添加依赖

 
 <dependency>
      <groupId>org.mybatis.generatorgroupId>
      <artifactId>mybatis-generator-coreartifactId>
      <version>1.3.3version>
  dependency>

2、配置generatorConfig.xml （文章最后附详细注释版配置文件）

<generatorConfiguration>
    
    <properties resource="generator.properties"/>
    
    <context id="mysql" defaultModelType="flat" 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="`"/>

        
        <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
        
        <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
        
        <commentGenerator type="com.liubj.mall.tiny.mbg.CommentGenerator">
            
            <property name="suppressAllComments" value="true"/>
            
            <property name="suppressDate" value="true"/>
            
            <property name="addRemarkComments" value="true"/>
        commentGenerator>

        
        <jdbcConnection driverClass="${jdbc.driverClass}"
                        connectionURL="${jdbc.connectionURL}"
                        userId="${jdbc.userId}"
                        password="${jdbc.password}">
            
            <property name="nullCatalogMeansCurrent" value="true" />
        jdbcConnection>

        
        <javaTypeResolver type="org.mybatis.generator.internal.types.JavaTypeResolverDefaultImpl">
            <property name="forceBigDecimals" value="false"/>
        javaTypeResolver>

        
        <javaModelGenerator targetPackage="com.liubj.mall.tiny.mbg.model" targetProject="mall-tiny-01\src\main\java">
            
            <property name="trimStrings" value="true"/>
        javaModelGenerator>

        
        <sqlMapGenerator targetPackage="com.liubj.mall.tiny.mbg.mapper" targetProject="mall-tiny-01\src\main\resources" />

        
        <javaClientGenerator targetPackage="com.liubj.mall.tiny.mbg.mapper" type="XMLMAPPER" targetProject="mall-tiny-01\src\main\java" />

        
        <table tableName="pms_brand">
            <generatedKey column="id" sqlStatement="MySql" identity="true"/>
            <columnOverride column="dec" jdbcType="VARCHAR" />
        table>
    context>
generatorConfiguration>

3、配置数据源generator.properties文件

jdbc.driverClass=com.mysql.cj.jdbc.Driver
jdbc.connectionURL=jdbc:mysql://ip地址:3306/数据库名称?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
jdbc.userId=root
jdbc.password=root

4、自定义注释生成器 CommentGenerator.java

package com.liubj.mall.tiny.mbg;

import org.mybatis.generator.api.IntrospectedColumn;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.dom.java.Field;
import org.mybatis.generator.internal.DefaultCommentGenerator;
import org.mybatis.generator.internal.util.StringUtility;

import java.util.Properties;

/**
 *自定义注释生成器
 */
public class CommentGenerator extends DefaultCommentGenerator {
    private boolean addRemarkComments = false;

    /**
     * 设置用户配置的参数
     */
    @Override
    public void addConfigurationProperties(Properties properties) {
        super.addConfigurationProperties(properties);
        this.addRemarkComments = StringUtility.isTrue(properties.getProperty("addRemarkComments"));
    }

    /**
     * 给字段添加注释
     */
    @Override
    public void addFieldComment(Field field, IntrospectedTable introspectedTable,
                                IntrospectedColumn introspectedColumn) {
        String remarks = introspectedColumn.getRemarks();
        //根据参数和备注信息判断是否添加备注信息
        if (addRemarkComments && StringUtility.stringHasValue(remarks)) {
            addFieldJavaDoc(field, remarks);
        }
    }

    /**
     * 给model的字段添加注释
     */
    private void addFieldJavaDoc(Field field, String remarks) {
        //文档注释开始
        field.addJavaDocLine("/**");
        //获取数据库字段的备注信息
        String[] remarkLines = remarks.split(System.getProperty("line.separator"));
        for (String remarkLine : remarkLines) {
            field.addJavaDocLine(" * " + remarkLine);
        }
        addJavadocTag(field, false);
        field.addJavaDocLine(" */");
    }
}

5、MyBatis Generator生产类 Generator.java

package com.liubj.mall.tiny.mbg;

import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * 用于生成MBG
 */
public class Generator {
    public static void main(String[] args) throws Exception {
        //MBG 执行过程中的警告信息
        List<String> warnings = new ArrayList<String>();
        //当生成的代码重复时，覆盖原代码
        boolean overwrite = true;
        //读取我们的 MBG 配置文件
        InputStream is = Generator.class.getResourceAsStream("/generatorConfig.xml");
        //配置警告信息
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(is);
        is.close();

        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        //创建 MBG
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        //执行生成代码
        myBatisGenerator.generate(null);
        //输出警告信息
        for (String warning : warnings) {
            System.out.println(warning);
        }
    }
}

三、详细注释版generatorConfig.xml（转）

<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="`"/>

    
    <plugin type="org.mybatis.generator.plugins.SerializablePlugin"/>
    
    <plugin type="org.mybatis.generator.plugins.ToStringPlugin"/>
    
    <commentGenerator type="com.liubj.mall.tiny.mbg.CommentGenerator">
        
        <property name="suppressAllComments" value="true"/>
        
        <property name="suppressDate" value="true"/>
        
        <property name="addRemarkComments" value="true"/>
    commentGenerator>
   
    
    <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>

文章中如有不当或错误之处请多多指教。