Mybatis七（MBG 逆向工程）

Posted 2021-02-04 FLGB

官方地址：http://www.mybatis.org/generator/

                 https://github.com/mybatis/generator/releases

 

<1>编写mbg.xml配置文件 

<?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">
        <commentGenerator>
            <!-- 是否去除自动生成的注释 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true" />
        </commentGenerator>
        <!--数据库连接的信息：驱动类、连接地址、用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
            connectionURL="jdbc:mysql://localhost:3306/mybatis" userId="root"
            password="root">
        </jdbcConnection>
        
        <!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver" connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:user" 
            userId=user" password="root123"> </jdbcConnection> -->

        <!-- 默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL 
            和 NUMERIC 类型解析为java.math.BigDecimal -->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!-- targetProject:生成PO类的位置 -->
        <javaModelGenerator targetPackage="com.generator.model"
            targetProject=".src">
            <!-- enableSubPackages:是否让schema作为包的后缀 -->
            <property name="enableSubPackages" value="false" />
            <!-- 从数据库返回的值被清理前后的空格 -->
            <property name="trimStrings" value="true" />
        </javaModelGenerator>
        <!-- targetProject:mapper映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.generator.mapper"
            targetProject=".src">
            <!-- enableSubPackages:是否让schema作为包的后缀 -->
            <property name="enableSubPackages" value="false" />
        </sqlMapGenerator>
        <!-- targetPackage：mapper接口生成的位置 -->
        <javaClientGenerator type="XMLMAPPER"
            targetPackage="com.generator.mapper" targetProject=".src">
            <!-- enableSubPackages:是否让schema作为包的后缀 -->
            <property name="enableSubPackages" value="false" />
        </javaClientGenerator>
        <!-- 指定数据库表 -->
        <table tableName="user" domainObjectName="User"></table>
        <table tableName="department"></table>
    </context>
</generatorConfiguration>

<2>建立pacage，对应目录

<3>编写生成代码类，运行后刷新目录

public class MybatisGeneratorTest {
    
    @Test
    public void generator() throws Exception{
 
        List<String> warnings = new ArrayList<String>();
        boolean overwrite = true;
        //指定 逆向工程配置文件
        File configFile = new File("config/mbg.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);
 
    } 
}

<4>.生成的逆向工程测试

 public void testSelectByExample() {
        String resource = "mybatis-config.xml";
        InputStream inputStream;
        try {
            inputStream = Resources.getResourceAsStream(resource);
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
            SqlSession sqlSession = sqlSessionFactory.openSession();
            UserMapper mapper = sqlSession.getMapper(UserMapper.class);
            UserExample example = new UserExample();

             //Criteria类是UserExample类里面的内部类，Criteria类是干什么用的呢？它专门用于封装自定义查询条件的
             Criteria criteria = example.createCriteria();
             criteria.andGenderEqualTo("1");
             criteria.andLastNameLike("%张%");

　　　　　　　　// 执行查询  

 　　　　　　　List<User> list = mapper.selectByExample(example);

for (User user : list) {
                System.out.println(user);
            }
            sqlSession.commit();
            // 释放资源
            sqlSession.close();
        } catch (Exception e) {
            e.printStackTrace();
        }