JavaWeb_(Mybatis框架)MyBatis Generator简单入门

　　　　官方文档　　传送门

　　　　下载地址　　传送门

MyBatis Generator（MBG）简介：

　　MyBatis Generator（MBG）是MyBatis MyBatis 和iBATIS的代码生成器。它将为所有版本的MyBatis以及版本2.2.0之后的iBATIS版本生成代码。它将内省数据库表（或许多表），并将生成可用于访问表的工件。这减少了设置对象和配置文件以与数据库表交互的初始麻烦。MBG寻求对简单CRUD（创建，检索，更新，删除）的大部分数据库操作产生重大影响。您仍然需要为连接查询或存储过程手动编写SQL和对象代码。

　　

创建一个简单的MyBatis Generator项目

　　1、搭建MBG项目；
　　　　a)下载MBG核心包；
　　　　b)创建java项目；
　　　　c)从官方文档获取配置表、实例代码；
　　　　d)导入依赖包；
　　2、MBG配置以及根据数据库表生成所需文件（Bean、Interface、Mapper.xml）；
　　3、使用自动生成的文件操作数据库；

　　准备数据库

　　

　　

/*
SQLyog Professional v12.08 (64 bit)
MySQL - 5.5.49 : Database - ssm_mybatis
*********************************************************************
*/

/*!40101 SET NAMES utf8 */;

/*!40101 SET SQL_MODE=''*/;

/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;
CREATE DATABASE /*!32312 IF NOT EXISTS*/`ssm_mybatis` /*!40100 DEFAULT CHARACTER SET utf8 */;

USE `ssm_mybatis`;

/*Table structure for table `country` */

DROP TABLE IF EXISTS `country`;

CREATE TABLE `country` (
  `c_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '国家id',
  `c_countryname` varchar(128) NOT NULL COMMENT '国家名称',
  `c_capital` varchar(128) DEFAULT NULL COMMENT '国家首都名称',
  PRIMARY KEY (`c_id`)
) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8;

/*Data for the table `country` */

insert  into `country`(`c_id`,`c_countryname`,`c_capital`) values (1,'中国','北京'),(3,'美国','华盛顿'),(4,'英国','伦敦'),(5,'日本','东京');

/*Table structure for table `user` */

DROP TABLE IF EXISTS `user`;

CREATE TABLE `user` (
  `u_id` int(11) NOT NULL AUTO_INCREMENT COMMENT '用户id',
  `u_username` varchar(64) NOT NULL COMMENT '用户名',
  `u_password` varchar(64) DEFAULT NULL COMMENT '用户密码',
  `u_sex` varchar(16) DEFAULT NULL COMMENT '用户性别',
  `u_createTime` datetime DEFAULT NULL COMMENT '用户创建时间',
  `u_cid` int(11) DEFAULT NULL COMMENT '用户国家id',
  PRIMARY KEY (`u_id`),
  KEY `FK_user_cid` (`u_cid`),
  CONSTRAINT `FK_user_cid` FOREIGN KEY (`u_cid`) REFERENCES `country` (`c_Id`) ON DELETE NO ACTION ON UPDATE NO ACTION
) ENGINE=InnoDB AUTO_INCREMENT=13 DEFAULT CHARSET=utf8;

/*Data for the table `user` */

insert  into `user`(`u_id`,`u_username`,`u_password`,`u_sex`,`u_createTime`,`u_cid`) values (1,'老王','','',NULL,1),(2,'jack','','',NULL,3),(3,'alice','ali111','',NULL,3),(4,'王司机','','',NULL,1),(5,'anna','ali111','',NULL,4),(6,'李师傅','','',NULL,1),(7,'漩涡鸣人','','',NULL,5),(8,'娜美','','',NULL,5),(9,'王五','abc','',NULL,1),(10,'老赵',NULL,NULL,NULL,NULL),(11,'老孙',NULL,NULL,NULL,NULL),(12,'98k',NULL,NULL,NULL,NULL);

/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40014 SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS */;
/*!40111 SET SQL_NOTES=@OLD_SQL_NOTES */;

ssm_mybatis.sql

package com.Gary.test;

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

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;

public class Generator {

    public static void main(String[] args) throws Exception{
           List<String> warnings = new ArrayList<String>();
           boolean overwrite = true;
           //读取src目录下generatorConfig.xml配置文件
           File configFile = new File("src/generatorConfig.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);
    }

}

Generator.java

<?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>

</generatorConfiguration>

generatorConfig.xml

　　Mybatis-Generator-Config配置及生成所需文件

<!-- 配置数据库链接的包  jar包已经放到项目中 -->
  <!-- <classPathEntry location="/Program Files/IBM/SQLLIB/java/db2java.zip" /> -->

  <context id="MyGenerator" targetRuntime="MyBatis3">
      <!-- 数据库连接信息 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/ssm_mybatis"
        userId="root"
        password="123456">
    </jdbcConnection>

    <!-- JAVA JDBC类型转换 配置信息的转换规则 -->
    <javaTypeResolver >
      <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>

    <!-- 重点  javaModelGenerator javaBean配置
        targetPackage 输出路径
        targetProject 输出项目位置  -->
    <javaModelGenerator targetPackage="com.Gary.bean" targetProject="src">
      <!-- 是否开启子包名称 是否在包名后边加上scheme名称 -->
      <property name="enableSubPackages" value="false" />
      <!-- 在Set中加入trim -->
      <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!-- mapper.xml配置 -->
    <sqlMapGenerator targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="false" />
    </sqlMapGenerator>

    <!-- java接口 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 数据库中的表  根据数据库中表来生成 -->
    <table tableName="user"/>
    <table tableName="country"/>

    <!--
    <table schema="DB2ADMIN" tableName="ALLTYPES" domainObjectName="Customer" >
      <property name="useActualColumnNames" value="true"/>
      <generatedKey column="ID" sqlStatement="DB2" identity="true" />
      <columnOverride column="DATE_FIELD" property="startDate" />
      <ignoreColumn column="FRED" />
      <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" />
    </table>
    -->

  </context>

<?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>

  <!-- 配置数据库链接的包  jar包已经放到项目中 -->
  <!-- <classPathEntry location="/Program Files/IBM/SQLLIB/java/db2java.zip" /> -->

  <context id="MyGenerator" targetRuntime="MyBatis3">
      <!-- 数据库连接信息 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/ssm_mybatis"
        userId="root"
        password="123456">
    </jdbcConnection>

    <!-- JAVA JDBC类型转换 配置信息的转换规则 -->
    <javaTypeResolver >
      <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>

    <!-- 重点  javaModelGenerator javaBean配置
        targetPackage 输出路径
        targetProject 输出项目位置  -->
    <javaModelGenerator targetPackage="com.Gary.bean" targetProject="src">
      <!-- 是否开启子包名称 是否在包名后边加上scheme名称 -->
      <property name="enableSubPackages" value="false" />
      <!-- 在Set中加入trim -->
      <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!-- mapper.xml配置 -->
    <sqlMapGenerator targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="false" />
    </sqlMapGenerator>

    <!-- java接口 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 数据库中的表  根据数据库中表来生成 -->
    <table tableName="user"/>
    <table tableName="country"/>

    <!--
    <table schema="DB2ADMIN" tableName="ALLTYPES" domainObjectName="Customer" >
      <property name="useActualColumnNames" value="true"/>
      <generatedKey column="ID" sqlStatement="DB2" identity="true" />
      <columnOverride column="DATE_FIELD" property="startDate" />
      <ignoreColumn column="FRED" />
      <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" />
    </table>
    -->

  </context>
</generatorConfiguration>

generatorConfig.xml

　　执行Generator.java代码后Refresh，可以看到Generator帮我们生成好了一系列的工程文件

package com.Gary.test;

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

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;

public class Generator {

    public static void main(String[] args) throws Exception{
           List<String> warnings = new ArrayList<String>();
           boolean overwrite = true;
           //读取src目录下generatorConfig.xml配置文件
           File configFile = new File("src/generatorConfig.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);
    }

}

Generator.java

<?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>

  <!-- 配置数据库链接的包  jar包已经放到项目中 -->
  <!-- <classPathEntry location="/Program Files/IBM/SQLLIB/java/db2java.zip" /> -->

  <context id="MyGenerator" targetRuntime="MyBatis3">
      <!-- 数据库连接信息 -->
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/ssm_mybatis"
        userId="root"
        password="123456">
    </jdbcConnection>

    <!-- JAVA JDBC类型转换 配置信息的转换规则 -->
    <javaTypeResolver >
      <property name="forceBigDecimals" value="false" />
    </javaTypeResolver>

    <!-- 重点  javaModelGenerator javaBean配置
        targetPackage 输出路径
        targetProject 输出项目位置  -->
    <javaModelGenerator targetPackage="com.Gary.bean" targetProject="src">
      <!-- 是否开启子包名称 是否在包名后边加上scheme名称 -->
      <property name="enableSubPackages" value="false" />
      <!-- 在Set中加入trim -->
      <property name="trimStrings" value="true" />
    </javaModelGenerator>

    <!-- mapper.xml配置 -->
    <sqlMapGenerator targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="false" />
    </sqlMapGenerator>

    <!-- java接口 -->
    <javaClientGenerator type="XMLMAPPER" targetPackage="com.Gary.bean"  targetProject="src">
      <property name="enableSubPackages" value="true" />
    </javaClientGenerator>

    <!-- 数据库中的表  根据数据库中表来生成 -->
    <table tableName="user"/>
    <table tableName="country"/>

    <!--
    <table schema="DB2ADMIN" tableName="ALLTYPES" domainObjectName="Customer" >
      <property name="useActualColumnNames" value="true"/>
      <generatedKey column="ID" sqlStatement="DB2" identity="true" />
      <columnOverride column="DATE_FIELD" property="startDate" />
      <ignoreColumn column="FRED" />
      <columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" />
    </table>
    -->

  </context>
</generatorConfiguration>

generatorConfig.xml

　　发现Generator帮我们自动生成了很多元素的注释，可以在generatorConfig.xml中配置不需要生成这些注释

      <!-- 这个标签可以去掉注释 -->
      <commentGenerator>
          <!-- 去掉注释 -->
          <property name="suppressAllComments" value="true"/>
          <!-- 去掉时间戳 -->
          <property name="suppressDate" value="true"/>
      </commentGenerator>

　　Generator使用生成的文件操作数据库

　　在user对象中生成toString()方法

　　测试：

　　一、按主键查询语句

    //按主键查询
    User user = mapper.selectByPrimaryKey(1);
    System.out.println(user);

　　二、条件查询语句

　　UserExample example = new UserExample();
　　//将条件封装到createCriteria集合中
　　example.createCriteria().andUSexEqualTo("1").andUUsernameLike("%王%");

　　//按条件查询
　　List<User> list = mapper.selectByExample(example);

　　for (User user : list) {
　　　　System.out.println(user);
　　}

　　三、插入数据语句

    User user = new User() ;
    user.setuUsername("赵云");

    mapper.insertSelective(user);

    session.commit();

package com.Gary.test;

import java.io.IOException;
import java.io.InputStream;
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 com.sikiedu.bean.User;
import com.sikiedu.bean.UserExample;
import com.sikiedu.mapper.UserMapper;

public class MapperTest {

    @Test
    public void Test1() throws IOException {
        String resource = "sqlMapConfig.xml";
        InputStream in = Resources.getResourceAsStream(resource );
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(in);
        SqlSession session = ssf.openSession();

        UserMapper mapper = session.getMapper(UserMapper.class);

        //按住键查询
        User user = mapper.selectByPrimaryKey(1);
        System.out.println(user);
    }

    @Test
    public void Test2() throws IOException {
        String resource = "sqlMapConfig.xml";
        InputStream in = Resources.getResourceAsStream(resource );
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(in);
        SqlSession session = ssf.openSession();

        UserMapper mapper = session.getMapper(UserMapper.class);

        UserExample example = new UserExample();
        //将条件封装到createCriteria集合中
        example.createCriteria().andUSexEqualTo("1").andUUsernameLike("%王%");

        //按条件查询
        List<User> list = mapper.selectByExample(example);

        for (User user : list) {
            System.out.println(user);
        }

    }

    @Test
    public void Test3() throws IOException {
        String resource = "sqlMapConfig.xml";
        InputStream in = Resources.getResourceAsStream(resource );
        SqlSessionFactory ssf = new SqlSessionFactoryBuilder().build(in);
        SqlSession session = ssf.openSession();

        UserMapper mapper = session.getMapper(UserMapper.class);
        User user = new User() ;
        user.setuUsername("赵云");

        mapper.insertSelective(user);

        session.commit();
    }

}

MapperTest.java