mybatis逆向工程mbg

Posted 2020-10-25 云晴

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mbg：mybatis generator=mybatis代码生成器

1.看一下项目结构

其中bean文件，mapper接口文件和mapper.xml文件是代码生成器自动生成的。

使用generator生成器的方法，百度mybatis,进入git仓库，点mybatis,找到generator就是生成器的源码和使用方法说明书。

首先，编写一个dmscq.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>
<!-- targetRuntime="MyBatis3":生成mybatis豪华框架，如果是MyBatis3Simple则生成简单框架 -->
  <context id="DB2Tables" targetRuntime="Mybatis3">
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/db_blog?allowMultiQueries=true"
        userId="root"
        password="5678">
    </jdbcConnection>

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

<!-- 指定javabean的生成策略
targetPackage：目标包名  targetProject：目标工程-->
    <javaModelGenerator targetPackage="com.atguigu.mybatis.bean" targetProject=".\\src">
      <property name="enableSubPackages" value="true" />
      <property name="trimStrings" value="true" />
    </javaModelGenerator>
<!-- sqlMapGenerator：sql映射生成策略： -->
    <sqlMapGenerator targetPackage="com.atguigu.mybatis.dao"  targetProject=".\\conf">
      <property name="enableSubPackages" value="true" />
    </sqlMapGenerator>
<!-- javaClientGenerator:指定mapper接口所在的位置 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="com.atguigu.mybatis.dao"  targetProject=".\\src">
      <property name="enableSubPackages" value="true" />
    </javaClientGenerator>
<!-- 指定要逆向分析哪些表：根据表要创建javaBean -->
    <table tableName="t_blogger" domainObjectName="Blogger"></table>
    <table tableName="t_dep" domainObjectName="Department"></table>

  </context>
</generatorConfiguration>

写好配置文件后，去test类中写一个生成的方法。

package com.atguigu.mybatis.test;

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

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;
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 com.atguigu.mybatis.bean.Blogger;
import com.atguigu.mybatis.bean.BloggerExample;
import com.atguigu.mybatis.bean.BloggerExample.Criteria;
import com.atguigu.mybatis.dao.BloggerMapper;


public class MyBatisTest {

    public SqlSessionFactory getSqlSessionFactory() throws IOException {
        String resource = "mybatis-config.xml";
        InputStream inputStream = Resources.getResourceAsStream(resource);
        return new SqlSessionFactoryBuilder().build(inputStream);
    }
//生成代码根据配置文件
    @Test
    public void runDmscq() throws Exception{
           List<String> warnings = new ArrayList<String>();
           boolean overwrite = true;
           File configFile = new File("dmscq.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);
    }
//测试生成代码
    @Test
    public void getBloggerByExample() throws Exception {
        SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
        SqlSession openSession = sqlSessionFactory.openSession();
        BloggerMapper mapper = openSession.getMapper(BloggerMapper.class);
        //selectByExample:查询根据条件，条件为null则是查询所有。
        /*List<Blogger> selectByExample = mapper.selectByExample(null);
        for (Blogger blogger : selectByExample) {
            System.out.println(blogger);
        }*/
        //查询username中带e的并且profile中带e的
        BloggerExample bloggerExample = new BloggerExample();
        Criteria createCriteria = bloggerExample.createCriteria();
        createCriteria.andUsernameLike("%e%");
        createCriteria.andProfileLike("%e%");
        /*List<Blogger> list = mapper.selectByExample(bloggerExample);
        for (Blogger blogger : list) {
            System.out.println(blogger);
        }*/
        //如果加个条件，查询username中带e的并且profile中带e的，（或者sign中带c的）
        Criteria criteriaCriteria2 = bloggerExample.createCriteria();
        criteriaCriteria2.andSignLike("%c%");
        //和之前的条件进行拼装
        bloggerExample.or(criteriaCriteria2);
        List<Blogger> blo = mapper.selectByExample(bloggerExample);
        for (Blogger blogger : blo) {
            System.out.println(blogger);
        }
        
        
        
        
    }


}

以上测试代码分别测试了，黄色查询所有的blogger,绿色的查询username和profile中都带e的。最后所有没注释掉的代码是查询username和profile中都带e或者sign中带c的