集成 spring + mybatis + mybatisplus

项目结构如下

1）引入依赖

特别说明: Mybatis 及 Mybatis-Spring 依赖请勿加入项目配置，以免引起版本冲突！！！ Mybatis-Plus 会自动帮你维护！

还有一点：我的mysql是8.0的，如果用 <artifactId>mysql-connector-java</artifactId>

<version>5.1.37</version>，连接数据库会有问题

<dependencies>
    <!-- mp 依赖
    mybatisplus 会自动维护mybatis 和 mybatis-spring
    -->
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus</artifactId>
        <version>2.3</version>
    </dependency>     <!--junit -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.9</version>
    </dependency>   <!-- log4j -->
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>   <!-- c3p0 -->
    <dependency>
        <groupId>com.mchange</groupId>
        <artifactId>c3p0</artifactId>
        <version>0.9.5.2</version>
    </dependency>   <!-- mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.45</version>
    </dependency>   <!-- spring -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
</dependencies>

2）加入mybatis的全局配置文件

这里mybatis的相关配置全放到spring的配置文件中了

<?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>

</configuration>

3）加入log4j.xml 和 db.properties

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
 
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
 
 <appender name="STDOUT" class="org.apache.log4j.ConsoleAppender">
   <param name="Encoding" value="UTF-8" />
   <layout class="org.apache.log4j.PatternLayout">
    <param name="ConversionPattern" value="%-5p %d{MM-dd HH:mm:ss,SSS} %m  (%F:%L) 
" />
   </layout>
 </appender>
 <logger name="java.sql">
   <level value="debug" />
 </logger>
 <logger name="org.apache.ibatis">
   <level value="info" />
 </logger>
 <root>
   <level value="debug" />
   <appender-ref ref="STDOUT" />
 </root>
</log4j:configuration>

4）spring的全局配置文件

<?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"
   xmlns:tx="http://www.springframework.org/schema/tx"
   xmlns:mybatis-spring="http://mybatis.org/schema/mybatis-spring"
   xsi:schemaLocation="http://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring-1.2.xsd
      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-4.0.xsd
      http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.0.xsd">
   
   
   <!-- 数据源 -->
   <context:property-placeholder location="classpath:db.properties"/>
   <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
      <property name="driverClass" value="${jdbc.driver}"></property>
      <property name="jdbcUrl" value="${jdbc.url}"></property>
      <property name="user" value="${jdbc.username}"></property>
      <property name="password" value="${jdbc.password}"></property>
   </bean>
   
   <!-- 事务管理器 -->
   <bean id="dataSourceTransactionManager" 
      class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
      <property name="dataSource" ref="dataSource"></property>
   </bean>
   <!-- 基于注解的事务管理 -->
   <tx:annotation-driven transaction-manager="dataSourceTransactionManager"/>
   
   
   <!--  配置SqlSessionFactoryBean 
      Mybatis提供的: org.mybatis.spring.SqlSessionFactoryBean
      MP提供的:com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean
    -->
   <bean id="sqlSessionFactoryBean" class=""org.mybatis.spring.SqlSessionFactoryBean">
      <!-- 数据源 -->
      <property name="dataSource" ref="dataSource"></property>
      <property name="configLocation" value="classpath:mybatis.xml"></property>
      <!-- 别名处理 -->
      <property name="typeAliasesPackage" value="com.atguigu.mp.beans"></property>      
      
      <!-- 注入全局MP策略配置 -->
      <property name="globalConfig" ref="globalConfiguration"></property>
   </bean>
   
   <!-- 定义MybatisPlus的全局策略配置-->
   <bean id ="globalConfiguration" class="com.baomidou.mybatisplus.entity.GlobalConfiguration">
      <!-- 在2.3版本以后，dbColumnUnderline 默认值就是true -->
      <property name="dbColumnUnderline" value="true"></property>
      
      <!-- 全局的主键策略 -->
      <property name="idType" value="0"></property>
      
      <!-- 全局的表前缀策略配置 -->
      <property name="tablePrefix" value="tbl_"></property>
      
   </bean>

   
   <!-- 
      配置mybatis 扫描mapper接口的路径
    -->
   <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
      <property name="basePackage" value="com.atguigu.mp.mapper"></property>
   </bean>
</beans>

5）测试数据源

public class testMp {

    private ApplicationContext ioc  =new
            ClassPathXmlApplicationContext("applicationContext.xml");

    @Test
    public void test() throws SQLException {
        DataSource dataSource = ioc.getBean("dataSource", DataSource.class);
        System.out.println(dataSource);

        Connection connection = dataSource.getConnection();
        System.out.println(connection);
    }
}

6）集成mybatisplus

Mybatis-Plus 的集成非常简单，对于 Spring，我们仅仅需要把 Mybatis 自带的 MybatisSqlSessionFactoryBean 替换为 MP 自带的即可。

<bean id="sqlSessionFactoryBean" class="com.baomidou.mybatisplus.spring.MybatisSqlSessionFactoryBean">
   <!-- 数据源 -->
   <property name="dataSource" ref="dataSource"></property>
   <property name="configLocation" value="classpath:mybatis.xml"></property>
   <!-- 别名处理 -->
   <property name="typeAliasesPackage" value="com.atguigu.mp.beans"></property>      
   
   <!-- 注入全局MP策略配置 -->
   <property name="globalConfig" ref="globalConfiguration"></property>
</bean>