MyBatis简单入门

MyBatis和ibatis我现在只知道配置文件有点不同，读取配置文件的类不同。下面给出配置文件。

 

<!DOCTYPE configuration   
    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"   
    "http://mybatis.org/dtd/mybatis-3-config.dtd">  
    <!--mybatis3.0 和ibatis配置文件有点不同-->
<configuration>
<properties resource="jdbc.properties" />  
<environments default="tayfer">  
        <environment id="tayfer"> 
        <!-- 数据源 -->
        <transactionManager type="JDBC" />  
            <dataSource type="POOLED">  
                <property name="driver" value="${driver}" />  
                <property name="url" value="${url}" />  
                <property name="username" value="${username}" />  
                <property name="password" value="${password}" />  
            </dataSource>  
        </environment>
</environments>

  <mappers>  
        <mapper resource="Person.xml" />  
  </mappers>
</configuration>

 配置文件的头是mybatis3.0哦。<properties resource="jdbc.properties" />这里指定了prooerties文件位置，不用可以直接把JDBC信息写在里面。 

 

<?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">
<!--<!DOCTYPE configuration   
    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"   
    "http://mybatis.org/dtd/mybatis-3-config.dtd"> -->
    <!--配置mapper映射-->

<mapper namespace="com.tuojin.mybatis.mapper.StuMapper">
	<!--<resultMap type="com.struts.test.Person" id="person">  
        <id property="id" column="d" javaType="int" jdbcType="INTEGER" />  
        <result property="name" column="name" javaType="String"  
            jdbcType="VARCHAR" />   
    </resultMap>
    -->

<select id="selectperson" parameterType="int" resultType="com.struts.test.Person">  
        select *  
        from person where id=#{a}  
</select>
<select id="selectall" resultType="com.struts.test.Person">
	select *
	from person
</select>
<insert id="insertperson" parameterType="com.struts.test.Person">
	insert into
	person(id,name) values (#{id},#{name}) 
</insert>
<update id="updateperson" parameterType="com.struts.test.Person">
	update person 
	set name=#{name} where id=#{id}
</update>
<delete id="deleteperson" parameterType="int">
	delete from person 
	where id=#{id}
</delete>  
</mapper>

 这2个XML的头文件时不一样的。可以不用配置resultMap,直接用resultType。不管是查出来的是单条记录还是多天记录都可以直接用parameterType="com.struts.test.Person"。我还发现#{}这里面的参数可以是任意的。与参数无关，那他映射关系就不是根据{}里面的值确定的，空值的话就不行了。很奇怪很不解。package com.struts.test;

 

import java.io.IOException;
import java.io.Reader;
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;

public class PersonImpl {

    public static SqlSession getSession(){ 
    	SqlSession session=null;
   	     try {
			Reader reader=Resources.getResourceAsReader("configuration.xml");
			SqlSessionFactory sqlmapper=new SqlSessionFactoryBuilder().build(reader);
			 session=sqlmapper.openSession();	
		} catch (IOException e) {
			e.printStackTrace();
		} 
		return session;
    }
 public static void main(String[] args){
	 SqlSession session=PersonImpl.getSession();
	 /*List<Person> person=(ArrayList<Person>)session.selectList("selectall");
	 for(Person p:person)
	 System.out.print(p);*/
	 /* Person p1=new Person();
	  p1.setId(4);
	  p1.setName("hongbin");
	  session.insert("insertperson",p1);
	  session.commit();*/
	  /*Person p1=new Person();
	  p1.setId(2);
	  p1.setName("hongbin");
	  session.update("updateperson", p1);
	  session.commit();*/
	/* session.delete("deleteperson", 2);
	 session.commit();*/
	 Person person=(Person)session.selectOne("selectperson", 1);
	 System.out.print(person);
       }
   
 }

 这些就是实现方法了;简单的单表查询。继续学习中........