初识MyBatis

第一步：添加jar包和配置log4j.properties（在hibernate中人家提供了这种在console打印sql语句的机制，但是mybatis是不提供的，需要自己配置）

下载地址 https://github.com/mybatis/mybatis-3/releases
log4j.properties：文件的内容

log4j.rootLogger=DEBUG, Console  

  

#Console  

log4j.appender.Console=org.apache.log4j.ConsoleAppender  

log4j.appender.Console.layout=org.apache.log4j.PatternLayout  

log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n  

  

log4j.logger.java.sql.ResultSet=INFO  

log4j.logger.org.apache=INFO  

log4j.logger.java.sql.Connection=DEBUG  

log4j.logger.java.sql.Statement=DEBUG  

log4j.logger.java.sql.PreparedStatement=DEBUG

第二步：编写MyBatisConfig.xml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>
 <environments default="development">
   <environment id="development">
     <transactionManager type="JDBC">
     </transactionManager>
     <dataSource type="POOLED">
       <property name="driver" value="com.mysql.jdbc.Driver"/>
       <property name="url" value="jdbc:mysql://localhost:3306/mybatis"/>
       <property name="username" value="root"/>
       <property name="password" value="root"/>
     </dataSource>
   </environment>
 </environments>

 <mappers>
   <mapper resource="jike/book/map/jikeUser.xml"/>
 </mappers>

</configuration>

第三步：配置jikeUser.xml文件

<?xml version="1.0" encoding="UTF-8" ?>

<!DOCTYPE mapper

    PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"

    "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="/">

  <select id="findById"  parameterType="int"  resultType="com.jike.mybatis.User">

   select * from users where id=#{id}

  </select>

</mapper>

第四步：创建持续化类User.JAVA

package com.jike.mybatis;

public class User {

private int id;

private String username;

private String password;

public int getId() {
return id;

}

public void setId(int id) {
this.id = id;

}

public String getUsername() {
return username;

}

public void setUsername(String username) {
this.username = username;

}

public String getPassword() {
return password;

}

public void setPassword(String password) {
this.password = password;

}

}

最后一步：编写一个测试类

package com.jike.mybatis.MyBatisTest;

import java.io.IOException;

import java.io.Reader;

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.apache.log4j.lf5.util.Resource;

import com.jike.mybatis.User;

public class MyBatisTest {

public static void main(String[] args) {
String resource="jike/book/map/MyBatisConfig.xml";
Reader reader=null;
SqlSession session;
try {
reader=Resources.getResourceAsReader(resource);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
SqlSessionFactory sqlMapper=new SqlSessionFactoryBuilder()
.build(reader);
session=sqlMapper.openSession();
User temp=session.selectOne("findById",1);
System.out.println(temp.getUsername());

session.close();

}

}