（一）问候MyBatis3

第一节：MyBatis简介

　　百度百科

第二季：Mybatis版HolleWorld实现

　　例子：

　　

mybatis-config.xml：

 <?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>
     <properties resource="jdbc.properties"/> <!-- 引入jdbc.properties文件 -->
     <!-- 类型别名 -->
     <typeAliases>
         <typeAlias alias="Student" type="com.wishwzp.model.Student"/>
     </typeAliases>
     <!-- 开发环境，这里就写了一个id为development的数据环境 -->
     <environments default="development">
         <environment id="development">
             <transactionManager type="JDBC" />
             <dataSource type="POOLED">
                 <property name="driver" value="${jdbc.driverClassName}" />
                 <property name="url" value="${jdbc.url}" />
                 <property name="username" value="${jdbc.username}" />
                 <property name="password" value="${jdbc.password}" />
             </dataSource>
         </environment>
     </environments>

     <mappers>
         <mapper resource="com/wishwzp/mappers/StudentMapper.xml" />
     </mappers>

 </configuration>

jdbc.properties：

 jdbc.driverClassName=com.mysql.jdbc.Driver
 jdbc.url=jdbc:mysql://localhost:3306/db_mybatis?characterEncoding=utf-8
 jdbc.username=root
 jdbc.password=root

StudentTest.java:

 package com.wishwzp.service;

 import org.apache.ibatis.session.SqlSession;

 import com.wishwzp.mappers.StudentMapper;
 import com.wishwzp.model.Student;
 import com.wishwzp.util.SqlSessionFactoryUtil;

 public class StudentTest {

     public static void main(String[] args) {
         SqlSession sqlSession=SqlSessionFactoryUtil.openSession();
         StudentMapper studentMapper=sqlSession.getMapper(StudentMapper.class);
         //do work
         Student student=new Student("李四",11);
         int result=studentMapper.add(student);
         sqlSession.commit();
         if(result>0){
             System.out.println("添加成功！");
         }
     }
 }

SqlSessionFactoryUtil.java:

 package com.wishwzp.util;

 import java.io.InputStream;

 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 SqlSessionFactoryUtil {

     private static SqlSessionFactory sqlSessionFactory;

     public static SqlSessionFactory getSqlSessionFactory(){
         if(sqlSessionFactory==null){
             InputStream inputStream=null;
             try{
                 inputStream=Resources.getResourceAsStream("mybatis-config.xml");
                 sqlSessionFactory=new SqlSessionFactoryBuilder().build(inputStream);
             }catch(Exception e){
                 e.printStackTrace();
             }
         }
         return sqlSessionFactory;
     }

     public static SqlSession openSession(){
         return getSqlSessionFactory().openSession();
     }
 }

Student.java:

 package com.wishwzp.model;

 public class Student {

     private Integer id;
     private String name;
     private Integer age;

     public Student() {
         super();
         // TODO Auto-generated constructor stub
     }

     public Student(String name, Integer age) {
         super();
         this.name = name;
         this.age = age;
     }

     public Integer getId() {
         return id;
     }
     public void setId(Integer id) {
         this.id = id;
     }
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public Integer getAge() {
         return age;
     }
     public void setAge(Integer age) {
         this.age = age;
     }

 }

StudentMapper.java:

 package com.wishwzp.mappers;

 import com.wishwzp.model.Student;

 public interface StudentMapper {

     public int add(Student student);
 }

StudentMapper.xml:

 <?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="com.wishwzp.mappers.StudentMapper">

     <insert id="add" parameterType="Student"  >
         insert into t_student values(null,#{name},#{age})
     </insert>

 </mapper> 

数据库为db_mybatis：