一.整合MyBatis+Dao层+maven导包

1.配置pom.xml配置文件

<dependencies>
   <!--Junit-->
   <dependency>
       <groupId>junit</groupId>
       <artifactId>junit</artifactId>
       <version>4.12</version>
   </dependency>
   <!--数据库驱动-->
   <dependency>
       <groupId>mysql</groupId>
       <artifactId>mysql-connector-java</artifactId>
       <version>5.1.47</version>
   </dependency>
   <!-- 数据库连接池 -->
   <dependency>
       <groupId>com.mchange</groupId>
       <artifactId>c3p0</artifactId>
       <version>0.9.5.2</version>
   </dependency>

   <!--Servlet - JSP -->
   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>servlet-api</artifactId>
       <version>2.5</version>
   </dependency>
   <dependency>
       <groupId>javax.servlet.jsp</groupId>
       <artifactId>jsp-api</artifactId>
       <version>2.2</version>
   </dependency>
   <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>jstl</artifactId>
       <version>1.2</version>
   </dependency>

   <!--Mybatis-->
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis</artifactId>
       <version>3.5.2</version>
   </dependency>
   <dependency>
       <groupId>org.mybatis</groupId>
       <artifactId>mybatis-spring</artifactId>
       <version>2.0.2</version>
   </dependency>
   <!--Spring-->
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-webmvc</artifactId>
       <version>5.1.9.RELEASE</version>
   </dependency>
   <dependency>
       <groupId>org.springframework</groupId>
       <artifactId>spring-jdbc</artifactId>
       <version>5.1.9.RELEASE</version>
   </dependency>
</dependencies>

2.配置mybatis-config.xml

<?xml version="1.0" encoding="UTF8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
    <!--   配置文件都整合到spring中了，所以这里仅仅保留了以下几项-->
    <!--    1.给dao层起别名-->
    <typeAliases>
        <package name="com.why.bean"/>
    </typeAliases>
    <!--        2.映射一些mappers-->
    <mappers>
        <mapper class="com.why.mapper.BookMapper"/>
    </mappers>
</configuration>

3.写基本的javabean和dao层的类

 

 

 

接口对应的mapper：

<?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.why.mapper.BookMapper">
    <select id="getBookMsg" resultType="books">
        select  * from books;
    </select>
</mapper>

 4.为了便于区分，写一个mybatis和spring整合的xml

<?xml version="1.0" encoding="UTF8"?>
<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 https://www.springframework.org/schema/context/spring-context.xsd">
    <!--1.关联对应的数据源信息,就是我们写的properties的配置文件-->
    <context:property-placeholder location="classpath:db.properties"/>
    <!--2.使用数据源 这里我们用dbcp-->
    <bean class="com.mchange.v2.c3p0.ComboPooledDataSource" name="dataSource">
        <!--    测试发现 必须要加上jdbc.   不然报错-->
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
        <!-- c3p0连接池的私有属性 -->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!-- 关闭连接后不自动commit -->
        <property name="autoCommitOnClose" value="false"/>
        <!-- 获取连接超时时间 -->
        <property name="checkoutTimeout" value="10000"/>
        <!-- 当获取连接失败重试次数 -->
        <property name="acquireRetryAttempts" value="2"/>
        <!--    池子初始连接个数-->
        <property name="initialPoolSize" value="10"/>
    </bean>
    <!--3.配置SqlSessionFactoryBean-->
    <bean class="org.mybatis.spring.SqlSessionFactoryBean" name="sqlSessionFactory">
        <!--    使用数据源-->
        <property name="dataSource" ref="dataSource"/>
        <!--    融合mybatis-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>
    </bean>


    <!--        4.配置自动扫描dao接口来动态的将dao接口注入到spring中-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--       注入sqlsessionFactory-->
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
        <!--       要扫描的包 接口无法注册到包里面，之前是用类来继承接口进而实现整合，
                   而现在就直接可以通过扫描包将接口放入到spring-->
        <property name="basePackage" value="com.why.mapper"/>
    </bean>
</beans>