1.通过maven导入关于mybatis的jar包

可以通过阿里云的maven库直接下载相关jar包

<dependencies><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.5</version></dependency><dependency><groupId>MySQL</groupId><artifactId>mysql-connector-Java</artifactId><version>5.1.38</version></dependency></dependencies>

2.编写mybatis的配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

<environmentsdefault="development"><environmentid="development"><transactionManagertype="JDBC"/><!--配置数据库--><dataSourcetype="POOLED"><propertyname="driver"value="com.mysql.jdbc.Driver"/><propertyname="url"value="jdbc:mysql://localhost:3306/my_schema?useSSL=true"/><propertyname="username"value="root"/><propertyname="password"value=""/></dataSource></environment></environments><!--映射文件--><mappers><mapperresource="UserMapper.xml"/></mappers></configuration>

3.编写映射文件UserMapper.xml

<?xmlversion="1.0"encoding="UTF-8"?><!DOCTYPEmapperPUBLIC"-//mybatis.org//DTDMapper3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd"><mappernamespace="userMapper"><selectid="selectUser"resultType="entity.User">select*fromuser</select></mapper>

4.写出实体类User,很平常的类,就不在过多解释.

publicclassUser{privateStringusername;privateStringemail;privateStringpassword;privateStringcreate_time;publicStringgetUsername(){returnusername;}publicvoidsetUsername(Stringusername){this.username=username;}publicStringgetEmail(){returnemail;}publicvoidsetEmail(Stringemail){this.email=email;}publicStringgetPassword(){returnpassword;}publicvoidsetPassword(Stringpassword){this.password=password;}publicStringgetCreate_time(){returncreate_time;}publicvoidsetCreate_time(Stringcreate_time){this.create_time=create_time;}@OverridepublicStringtoString(){return"User[username="+username+",email="+email+",password="+password+",create_time="+create_time+"]";}publicUser(Stringusername,Stringemail,Stringpassword,Stringcreate_time){super();this.username=username;this.email=email;this.password=password;this.create_time=create_time;}publicUser(){super();}

}

5.在写一个类MybatisSamples,里面包含main方法,进行测试.

具体代码如下

publicstaticvoidmain(String[]args){Stringresource="mybatis-config.xml";SqlSessionsession=null;try{InputStreamis=Resources.getResourceAsStream(resource);//获取一个session工厂SqlSessionFactorysqlSessionFactory=newSqlSessionFactoryBuilder().build(is);//通过工厂获取sessionsession=sqlSessionFactory.openSession();//根据映射文件中select标签的id获取集合List<User>list=session.selectList("userMapper.selectUser");for(Useruser:list){System.out.println(user);}}catch(IOExceptione){//TODOAuto-generatedcatchblocke.printStackTrace();}finally{//注意关闭session!!!session.close();}}

执行结果如下:

附:
包结构

数据库结构

总结:想入门mybatis最重要的两步,第一是写配置文件,配置数据库和mapper,第二步是写好mapper和实体类,mapper中写sql语句,然后可以就可以通过mybatis把表中的数据映射成为一个对象了。