（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：