MyBatis Generator 逆向生成器

1 逆向工程

1.1 含义

逆向工程就是将传统的Mybatis的需要的三个组件（实体类，自定义Mapper接口，Mapper接口对应的Mapper.xml文件）由手动创建变为自动创建，减轻开发者的代码量，提高工作效率。
           

1.2 如何使用

MyBatis Generator,简称MBG,是一个专门为Mybatis框架开发者定制的代码生成器。他可以自动创建Mybatis所需的三个组件：实体类、Mapper接口、Mapper.xml文件，支持基本的CRUD操作。但是一些复杂的SQL需要开发者手写。
           

1.2.1 新建maven工程，设置pom.xml

<dependencies>
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.5</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.21</version>
    </dependency>
    <dependency>
        <groupId>org.mybatis.generator</groupId>
        <artifactId>mybatis-generator-core</artifactId>
        <version>1.4.0</version>
    </dependency>
</dependencies>
           

1.2.2 创建MBG配置文件generatorConfig.xml

• jdbcConnection 配置数据库连接信息
• javaModelGenerator 配置JavaBean的生成策略
• sqlMapGenerator 配置SQL映射文件生成器
• javaClientGenerator 配置Mapper接口的生成策略
• table配置目标数据表（tableName:表名，domainObjectName:javaBean类名）

<?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="testTables" targetRuntime="MyBatis3">
        <jdbcConnection
                driverClass="com.mysql.cj.jdbc.Driver"
                connectionURL="jdbc:mysql://localhost:3306/learning?characterEncoding=UTF-8&amp;serverTimezone=UTC"
                userId="root"
                password="123456"
        >
        </jdbcConnection>
        <javaModelGenerator targetPackage="com.xh.mybatis.pojo" targetProject="./src/main/java"></javaModelGenerator>
        <sqlMapGenerator targetPackage="com.xh.mybatis.mapper" targetProject="./src/main/java"></sqlMapGenerator>
        <javaClientGenerator
                type="XMLMAPPER"
                targetPackage="com.xh.mybatis.mapper"
                targetProject="./src/main/java"></javaClientGenerator>
        <table tableName="tb_account" domainObjectName="Account"></table>
    </context>
</generatorConfiguration>
           

1.2.3 generatorConfig.xml文件的头信息

<?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">
           

1.2.4 测试

package com.xh.mybatis.test;

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

import javax.security.auth.callback.Callback;
import java.io.File;
import java.io.IOException;
import java.sql.SQLException;
import java.util.ArrayList;

/**
 * @program: mybatis-Inverse
 * @description:
 * @author: XH
 * @create: 2020-12-23 17:28
 **/
public class Main {
    public static void main(String[] args) {
        ArrayList<String> warings = new ArrayList<>();
        boolean overwrite = true;
        String genConfig = "/generatorConfig.xml";
        File configFile = new File(Main.class.getResource(genConfig).getFile());
        ConfigurationParser configurationParser = new ConfigurationParser(warings);
        Configuration configuration = null;
        try {
            configuration = configurationParser.parseConfiguration(configFile);
        } catch (IOException e) {
            e.printStackTrace();
        } catch (XMLParserException e) {
            e.printStackTrace();
        }
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator=null;
        try {
            myBatisGenerator = new MyBatisGenerator(configuration, callback, warings);
        } catch (InvalidConfigurationException e) {
            e.printStackTrace();
        }
        try {
            myBatisGenerator.generate(null);
        } catch (SQLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}