myBatis学习之路1-基本功能实现

myBatis也是一个持久型框架，相较于hibernate来说，算是轻量级的。

1.配置mybatis环境

　　相关jar下载地址：mybatis+mysalJAR包

2.新建一个java project工程

2.1配置log4j.properties文件，用于日志输出

 log4j.rootCategory=DEBUG, 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

log4j

2.2配置MybatisConfig.xml,用于配置数据库连接

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

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

 <configuration>
     <!-- 别名 -->
     <typeAliases>
         <typeAlias alias="User" type="com.juin.entity.User" />
         <typeAlias alias="Person" type="com.juin.entity.Person" />
     </typeAliases>

     <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_test"/>
     <property name="username" value="juin"/>
     <property name="password" value="123654"/>
     </dataSource>
     </environment>
     </environments>

     <mappers>
         <mapper resource="com/juin/map/juinUser.xml"/>
         <mapper resource="com/juin/map/person.xml"/>
         <mapper class="com.juin.map.IUser"/>
     </mappers>
 </configuration>

MyBatisConfig.xml

2.3配置juinUser.xml,前面忘记说了，mybatis实现了代码与数据库连接语句的分离。

 <?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="domain.blog.mappers.AuthorMapper">
     <select id="findById" parameterType="int" resultType="com.juin.entity.User">
         select * from user where id=#{id}
     </select>

     <insert id="insertUser" parameterType="User" statementType="PREPARED"
         keyProperty = "id" useGeneratedKeys = "true">
         insert into user (username,psw) values
         (#{username},#{psw})
     </insert>

     <update id="updateUser" parameterType="User">
         UPDATE User SET
         username=#{username},
         psw=#{psw}
         where id = #{id}
     </update>

     <select id="loginSelect" parameterType="hashmap" resultType="User">
         select * from user where username = #{username} and psw = #{psw}
     </select>

     <select id="loginSelect2" parameterType="User" resultType="User">
         select * from user where username = #{username} and psw = #{psw}
     </select>

     <select id="selectList" resultType="User">
         select * from user
     </select>

     <resultMap id="UserMap" type="User">
         <id property="id" column="id"/>
         <result property="username" column="username"/>
         <result property="psw" column="psw"/>
     </resultMap>
     <select id="selectUsers" resultMap="UserMap">
         select * from user
     </select>
 </mapper>

juinUser.xml

2.4创建User实体类

 package com.juin.entity;

 public class User {
     private int id;
     private String username;
     private String psw;

     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 getPsw() {
         return psw;
     }

     public void setPsw(String psw) {
         this.psw = psw;
     }
 }

User.java

2.5创建测试类

 package com.juin.test;

 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 com.juin.entity.User;

 public class test1 {

     public static void main(String[] args) {

         String resource = "com/juin/map/MybatisConfig.xml";
         Reader reader = null;
         SqlSession session = null;

         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", 2);
         System.out.println(temp.getUsername());
         session.close();
     }

 }

test