MyBatis学习总结（一）mybatis与spring整合

一、需要的jar包

1、spring相关jar包

2、Mybatis相关的jar包

3、Spring+mybatis相关jar包

4、MySql驱动包

5、数据库连接池包

二、配置文件

1、参数文件(db.properties)

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

2、spring相关（applicationContext.xml）

< ?xml version="1.0" encoding="UTF-8"?>
< beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

    <!--读取配置文件-->
    <context:property-placeholder location="classpath:db.properties"/>
    <!--配置数据源-->
    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driver}" />
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="10" />
        <property name="maxIdle" value="5" />
    </bean>

    <!--sqlSessionFactory-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:SqlMapConfig.xml" /> <!--name必须这么写-->
    </bean>

    <!--扫描包配置-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.mybatis.dao" />  <!--name必须这么写-->
    </bean>
</beans>

3、Mybatis相关（SqlMapConfig.xml && Mapper.xml）

3.1 Mybatis核心配置文件

<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <!--起别名-->
    <typeAliases>
          <package name="com.mybatis.pojo" />
    </typeAliases>
</configuration>

< typeAliases>说明：这个在此处是声明pojo的包路径，在mapper.xml文件中，对没个sql的parameterType和resultType可以直接使用pojo的类名，而不用写全路径，而且mapper中的类名和实际pojo的类名可以按照一定的规则不一定要完完全全相同，具体规则此处不赘述

3.2 Mapper映射文件

这只拿查询做一个例子，主要说明mybatis和spring整合的环境搭建

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.mybatis.dao.UserMapper">
    <select id="queryById" parameterType="Integer" resultType="user">
      select * from user where id = #{id};
    </select>
</mapper>

4、测试方法

@Test
public void testMybatis(){
    ApplicationContext ca = new ClassPathXmlApplicationContext("applicationContext.xml");
    UserMapper userMaper = (UserMapper) ca.getBean("userMapper");
    User user = userMaper.queryById(1);
    System.out.println(user);
}

5、pojo类

package com.mybatis.pojo;

import java.util.Date;

public class User {
    private String id;
    private String username;
    private String sex;
    private Date birthday;
    private String address;
    private String detail;
    private Integer score;

	get/set...
    toString
}