MyBatis研习录(14)——MyBatis逆向工程

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版权声明

• 本文原创作者：谷哥的小弟
• 作者博客地址：http://blog.csdn.net/lfdfhl

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概述

MyBatis逆向工程，简称MBG。它是一个专门为MyBatis框架使用者定制的代码生成器，它可以快速的根据表生成对应的映射文件xxxMapper.xml，接口xxxMapper.java，以及JavaBean类对象。

接下来，我们以示例的形式学习MBG的使用。

数据准备

DROP DATABASE IF EXISTS mybatisDatabase;
CREATE DATABASE mybatisDatabase;
use mybatisDatabase;
CREATE TABLE user(
  id INT PRIMARY KEY auto_increment,
  name VARCHAR(50),
  password VARCHAR(50),
  gender VARCHAR(10)
);

CREATE TABLE student(
  id INT PRIMARY KEY auto_increment,
  name VARCHAR(50),
  address VARCHAR(50),
  gender VARCHAR(10)
);

INSERT INTO user(name,password,gender) VALUES("lucy","123456","female");
INSERT INTO user(name,password,gender) VALUES("momo","234567","female");
INSERT INTO user(name,password,gender) VALUES("xixi","345678","female");
INSERT INTO user(name,password,gender) VALUES("pepe","456123","female");


INSERT INTO student(name,address,gender) VALUES("tome","BeiJing","female");
INSERT INTO student(name,address,gender) VALUES("dodo","ChengDu","female");
INSERT INTO student(name,address,gender) VALUES("mbmb","ZhangYe","female");
INSERT INTO student(name,address,gender) VALUES("zxzx","BaoDing","female");


SELECT * FROM user;
SELECT * FROM student;

搭建开发环境

创建普通的Java工程，结构如下：

在lib中一共存在四个jar包：

• log4j-1.2.17.jar
• mybatis-3.4.1.jar
• mybatis-generator-core-1.3.2.jar
• mysql-connector-java-5.1.7-bin.jar

其中，mybatis-generator-core-1.3.2.jar专门用于MyBatis逆向工程

log4j.properties

# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

generatorConfig.xml

在工程Mybatis012根目录下创建generatorConfig.xml，图示如下：

其内容如下：

<generatorConfiguration>
	
  <context id="MySQLTables" targetRuntime="MyBatis3Simple">

  	
	<commentGenerator>
        <property name="suppressAllComments" value="true" />
    commentGenerator>
  
    
    <jdbcConnection driverClass="com.mysql.jdbc.Driver"
        connectionURL="jdbc:mysql://localhost:3306/mybatisDatabase"
        userId="root"
        password="root">
    jdbcConnection>

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

	
    <javaModelGenerator targetPackage="cn.com.pojo" targetProject=".\src">
      <property name="enableSubPackages" value="true" />
      <property name="trimStrings" value="true" />
    javaModelGenerator>
	
	
    <sqlMapGenerator targetPackage="cn.com.mapper"  targetProject=".\src">
      <property name="enableSubPackages" value="true" />
    sqlMapGenerator>

	
    <javaClientGenerator type="XMLMAPPER" targetPackage="cn.com.mapper"  targetProject=".\src">
      <property name="enableSubPackages" value="true" />
    javaClientGenerator>

	
    <table tableName="user" domainObjectName="User" >table>
    <table tableName="student" domainObjectName="Student" >table>

  context>
  
generatorConfiguration>

Generator

在cn.com.generator包下建立Generator，其内容如下：

package cn.com.generator;

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generatorConfig.xml配置文件
		File configFile = new File("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);
	}

}

自动生成代码

运行Generator后再刷新整个Java工程即可见自动生成的代码，图示如下：

mybatis-config.xml

在自动生成代码后再创建并配置mybatis-config.xml文件，其内容如下：

<configuration>
    
	<environments default="development">
		<environment id="development">
			<transactionManager type="JDBC" />
			<dataSource type="POOLED">
				<property name="driver" value="com.mysql.jdbc.Driver" />
				<property name="url" value="jdbc:mysql://localhost:3306/mybatisDatabase" />
				<property name="username" value="root" />
				<property name="password" value="root" />
			dataSource>
		environment>
	environments>
	<mappers>
		
		<package name="cn.com.mapper" />
	mappers>
configuration>

MybatisTest

创建MybatisTest测试该逆向工程，其代码如下：

package cn.com.test;

import java.io.InputStream;
import java.util.Iterator;
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 cn.com.mapper.StudentMapper;
import cn.com.mapper.UserMapper;
import cn.com.pojo.Student;
import cn.com.pojo.User;
/**
 * 本文作者：谷哥的小弟
 * 博客地址：http://blog.csdn.net/lfdfhl
 */
public class MybatisTest {

	static SqlSessionFactory sqlSessionFactory = null;

	public static SqlSessionFactory getSqlSessionFactory() {
		try {
			if (sqlSessionFactory == null) {
				InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");
				SqlSessionFactoryBuilder sqlSessionFactoryBuilder = new SqlSessionFactoryBuilder();
				sqlSessionFactory = sqlSessionFactoryBuilder.build(inputStream);
			}
			return sqlSessionFactory;
		} catch (Exception e) {
			// TODO: handle exception
		} finally {

		}
		return null;
	}
	
	
	@Test
	public void testUser() {
		//获取SqlSession
		SqlSession sqlSession=getSqlSessionFactory().openSession();
		//利用SqlSession得到Mapper
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
		List<User> userList = userMapper.selectAll();
		Iterator<User> iterator = userList.iterator();
		while(iterator.hasNext()) {
			User user = iterator.next();
			System.out.println(user.getName()+" , "+user.getGender());
		}
		//关闭SqlSession
		sqlSession.close();
	}
	
	@Test
	public void testStudent() {
		//获取SqlSession
		SqlSession sqlSession=getSqlSessionFactory().openSession();
		//利用SqlSession得到Mapper
		StudentMapper studentMapper = sqlSession.getMapper(StudentMapper.class);
		Student student = studentMapper.selectByPrimaryKey(1);
		System.out.println(student.getName()+" , "+student.getGender());
		//关闭SqlSession
		sqlSession.close();
	}

}

测试结果如下：

附图

在此，附上整个项目的结构图，图示如下：