spring入门(六) spring mvc+mybatis

1.引入依赖

 <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
 <dependency>
     <groupId>org.mybatis</groupId>
     <artifactId>mybatis</artifactId>
     <version>3.4.5</version>
 </dependency>
 
 <!--spring的版本是5.0.9,mybatis-spring的版本要是1.3+ -->
 <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
 <dependency>
     <groupId>org.mybatis</groupId>
     <artifactId>mybatis-spring</artifactId>
     <version>1.3.2</version>
 </dependency>

2.在springmvc-config.xml增加mybatis配置

 <!-- 针对myBatis的配置项 -->
 <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
     <!-- 实例化sqlSessionFactory时需要使用上述配置好的数据源以及SQL映射文件 -->
     <property name="dataSource" ref="dataSource" />
     <!-- 自动扫描classpath:mapper/*.xml         -->
     <property name="mapperLocations" value="classpath:mapper/*.xml" />
 </bean>
 <!-- 配置扫描器 -->
 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
     <!-- 扫描com.ice.dao这个包以及它的子包下的所有映射接口类,省去了在每个mapper接口上注解 -->
     <property name="basePackage" value="com.ice.dao" />
     <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory" />
 </bean>

3.在classpath:mapper/ 创建CustomerMapper.xml

注意创建的位置,是在上面设置的 mapperLocations.

 <?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">
 <!--  namespace要跟后面该xml对应的mapper类的全名一致 -->
 <mapper namespace="com.ice.dao.CustomerMapper">
     <!--  id设置为mapper类对应的方法名, parameterType跟方法的参数类型一致,resultType跟方法的返回类型一致.
     如果返回单个对象,mybatis会自动调用selectOne方法;如果返回的是List,mybatis会自动调用selectList方法.
     -->
     <select id="getUser" parameterType="java.lang.String"
             resultType="com.ice.model.Customer">
         select id,name from customer where name=#{name}
     </select>
 </mapper>

4.创建CustomerMapper.xml对应的CustomerMapper.java

注意创建的位置,是在上面设置的 basePackage.

 package com.ice.dao;
 
 import com.ice.model.Customer;
 //不用在xml里配置该bean,也不用注解.已经配置了MapperScanner
 //<property name="basePackage" value="com.ice.dao" />
 public interface CustomerMapper {
 
     Customer getUser(String name);
 }

5.简单测试(在controller里测试,也可考虑springTest)

正式项目里,要有service层.

 package com.ice.controller;
 
 import com.ice.dao.CustomerMapper;
 import com.ice.model.Customer;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.ResponseBody;
 
 @Controller
 @RequestMapping("/mybatis")
 public class MybatisController {
 
     @Autowired
     private CustomerMapper customerMapper;
 
     @RequestMapping("/query")
     @ResponseBody
     public String index() {
         Customer user = customerMapper.getUser("hello");
         return "顾客id" + user.getId();
     }
 }