IDEA+Maven+Java代码测试的简单MyBatis逆向工程

简单MyBatis逆向工程步骤

添加maven依赖

<dependencies>
	<dependency>
		<groupId>org.mybatis.generator</groupId>
		<artifactId>mybatis-generator-core</artifactId>
		<version>1.3.5</version>
	</dependency>
	<dependency>
		<groupId>org.mybatis</groupId>
		<artifactId>mybatis</artifactId>
		<version>3.5.3</version>
	</dependency>
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
		<version>8.0.20</version>
	</dependency>
</dependencies>

配置MBG.xml

因为作者使用相对路径时会报找不到xml文件异常，所以xml中使用了绝对路径解决。

<?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="DB2Tables" targetRuntime="MyBatis3">
        <!--jdbcConnection：指导连接到哪个数据库-->
        <jdbcConnection
            driverClass="com.mysql.cj.jdbc.Driver"
            connectionURL="jdbc:mysql://localhost:3306/数据库名?serverTimezone=UTC"
            userId="数据库用户名"
            password="数据库用户密码">
        </jdbcConnection>

        <javaTypeResolver >
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!--javaModelGenerator：生成pojo
        targetPackage：生成的pojo放在哪个包
        targetProject：放在哪个工程下
        -->
        <javaModelGenerator targetPackage="com.atguigu.bean"
                            targetProject="E:\8、MyBatis_mbg\src\main\java">
            <property name="enableSubPackages" value="true" />
            <property name="trimStrings" value="true" />
        </javaModelGenerator>

        <!--sqlMapGenerator：sql映射文件生成器；指定xml生成的地方-->
        <sqlMapGenerator targetPackage="com.atguigu.dao"
                         targetProject="E:\8、MyBatis_mbg\src\main\resources">
            <property name="enableSubPackages" value="true" />
        </sqlMapGenerator>

        <!--javaClientGenerator：dao接口生成的地方-->
        <javaClientGenerator type="XMLMAPPER"
                             targetPackage="com.atguigu.dao"
                             targetProject="E:\8、MyBatis_mbg\src\main\java">
            <property name="enableSubPackages" value="true" />
        </javaClientGenerator>

        <!--table：指定要逆向生成哪个数据表
        tableName="t_teacher"：表名
        domainObjectName：这个表对应的对象名
        -->
        <table tableName="t_cat" domainObjectName="Cat" ></table>
        <table tableName="t_employee" domainObjectName="Employee" ></table>
        <table tableName="t_teacher" domainObjectName="Teacher" ></table>

    </context>
</generatorConfiguration>

写Java测试类

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

public class MBGTest {

    public static void main(String[] args) throws Exception {
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        File configFile = new File("E:\\8、MyBatis_mbg\\src\\main\\resources\\mbg.xml");
        ConfigurationParser cp = new ConfigurationParser(warnings);
        Configuration config = cp.parseConfiguration(configFile);
        DefaultShellCallback callback = new DefaultShellCallback(overwrite);
        MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings);
        //代码生成
        myBatisGenerator.generate(null);
    }
}

最后运行即可生成dao接口、xml实现文件、bean类

Maven最终结果如下

遇到的问题

Cannot resolve org.mybatis.generator:mybatis-generator:1.3.5

解决方案

1、打开Project Structure的Libraries

2、点击"+"号，搜索org.mybatis.generator:mybatis-generator-core:1.3.5，加入到依赖中即可