Spring与Mybatis结合例子详解

工程目录结构如下：

  

数据表：

配置：

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
id="WebApp_ID" version="2.5">
<display-name>springMybatis</display-name>

<!-- 配置文件位置，默认为/WEB-INF/applicationContext.xml -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:applicationContext.xml</param-value>
</context-param>

<!-- 字符集过滤器 -->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

<!-- 上下文Spring监听器 -->
<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!-- servlet控制跳转 -->
<servlet>
<servlet-name>spring</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置文件 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:context-dispatcher.xml</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>spring</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>

<welcome-file-list>
<welcome-file>index.html</welcome-file>
<welcome-file>index.htm</welcome-file>
<welcome-file>index.jsp</welcome-file>
<welcome-file>default.html</welcome-file>
<welcome-file>default.htm</welcome-file>
<welcome-file>default.jsp</welcome-file>
</welcome-file-list>
</web-app>  

web.xml中引用的配置文件applicationContext.xml和context-dispatcher.xml定义如下：

1.应用上下文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:p="http://www.springframework.org/schema/p"xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"xsi:schemaLocation="      http://www.springframework.org/schema/beans       http://www.springframework.org/schema/beans/spring-beans-3.0.xsd      http://www.springframework.org/schema/tx       http://www.springframework.org/schema/tx/spring-tx-3.0.xsd       http://www.springframework.org/schema/context       http://www.springframework.org/schema/context/spring-context-3.0.xsd"><!-- 引入jdbc配置文件 --><context:property-placeholder location="classpath:jdbc.properties" /><!--创建jdbc数据源 --><bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"destroy-method="close"><property name="driverClassName" value="${driver}" /><property name="url" value="${url}" /><property name="username" value="${username}" /><property name="password" value="${password}" /></bean><!-- (事务管理)transaction manager, use JtaTransactionManager for global tx --><bean id="transactionManager"class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource" /></bean><!-- 创建SqlSessionFactory，同时指定数据源 --><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource" /></bean><!-- 可通过注解控制事务 --><tx:annotation-driven /><!-- Mapper接口所在包名，Spring会自动查找其下的Mapper --><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.example.spring.mapper" /></bean></beans>  

其中，引用了jdbc.properties文件。没有必要在 Spring 的 XML 配置文件中注册所有的映射器，可以使用一个 MapperScannerConfigurer , 它 将 会 查 找 类 路 径 下 的 映 射 器 并 自 动 将 它 们 创 建 成 MapperFactoryBean，此处是自动查找com.example.spring.mapper包下的映射器。

2.上下文调度器context-dispatcher.xml:

<?xml version="1.0" encoding="UTF-8"?><beans default-lazy-init="true"xmlns="http://www.springframework.org/schema/beans"xmlns:p="http://www.springframework.org/schema/p" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="         http://www.springframework.org/schema/beans          http://www.springframework.org/schema/beans/spring-beans-3.0.xsd         http://www.springframework.org/schema/mvc          http://www.springframework.org/schema/mvc/spring-mvc-3.0.xsd          http://www.springframework.org/schema/context         http://www.springframework.org/schema/context/spring-context-3.0.xsd"><!-- 使用注解的包，包括子集 --><context:component-scan base-package="com.example.spring" /><!-- 通过注解，把URL映射到Controller上，该标签默认注册DefaultAnnotationHandlerMapping和AnnotationMethodHandlerAdapter --><mvc:annotation-driven /><!-- 视图解析器 --><bean id="viewResolver"class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="viewClass"value="org.springframework.web.servlet.view.JstlView" /><property name="prefix" value="/WEB-INF/pages/" /><property name="suffix" value=".jsp"></property></bean><bean id="multipartResolver"class="org.springframework.web.multipart.commons.CommonsMultipartResolver"p:defaultEncoding="UTF-8" /></beans>  

其中，视图解析器中定义了controller访问页面的默认前缀和后缀。

jdbc.properties:

driver=com.mysql.jdbc.Driverurl=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=utf-8username=rootpassword=root

LoginController.java:

package com.example.spring.controller;import java.util.HashMap;import java.util.List;import java.util.Map;import javax.servlet.http.HttpServletResponse;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.servlet.ModelAndView;import com.example.spring.entity.Student;import com.example.spring.service.StudentService;@Controller@RequestMapping(value = "background")public class LoginController {@Autowiredprivate StudentService studentService;@RequestMapping(value = "to_login")public ModelAndView toLogin(HttpServletResponse response) throws Exception {Map<String, Object> map = new HashMap<String, Object>();List<Student> result = studentService.findAll();map.put("result", result);return new ModelAndView("background/student", map);}}

其中，注解@Controller对应表现层的Bean，也就是Action；@RequestMapping在类前面表示访问controller时自动添加上的url前缀，在方法前面表示访问方法时自动添加上的前缀；如果StudentService.java中类前加有注解@Repository(value="studentServ")，则@Autowired等同于@Resource(name="studentServ"），相当于实例化了此接口。

如果去掉@Controller注解，运行警告：No mapping found for HTTP request with URI [/springMybatis/background/to_login] in DispatcherServlet with name 'spring'

Student.java:

package com.example.spring.entity;public class Student {private int id;private String name;private int age;private String major;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public int getAge() {return age;}public void setAge(int age) {this.age = age;}public String getMajor() {return major;}public void setMajor(String major) {this.major = major;}}

StudentMapper.java:

package com.example.spring.mapper;import java.util.List;import org.apache.ibatis.annotations.Param;import org.apache.ibatis.annotations.Result;import org.apache.ibatis.annotations.Results;import org.apache.ibatis.annotations.Select;import com.example.spring.entity.Student;public interface StudentMapper {@Select(value = "${sql}")@Results(value = { @Result(id = true, property = "id", column = "id"),@Result(property = "name", column = "s_name"), @Result(property = "age", column = "s_age"),@Result(property = "major", column = "s_major") })public List<Student> operateReturnBeans(@Param(value = "sql") String sql);}

其中，注解@Select表示它注解的方法会执行一个sql查询语句，此处可以替换为@Select("SELECT * FROM tb_student")，删除方法里面的参数，同样的效果。如果想通过id查询:@Select("SELECT * FROM tb_student WHERE id = #{id}")
operateReturnBeans(@Param(value = "id") int id);@Results是对返回结果字段的注解，如果使用的字段与表字段名相同，此注解可省略。

如果去掉@Param注解，运行异常：org.apache.ibatis.reflection.ReflectionException: There is no getter for property named 'sql' in 'class java.lang.String'

StudentService.java:

package com.example.spring.service;import java.util.List;import com.example.spring.entity.Student;public interface StudentService {/** * 查询所有 */public List<Student> findAll();}

StudentServiceImpl.java:

package com.example.spring.service.impl;import java.util.List;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import com.example.spring.entity.Student;import com.example.spring.mapper.StudentMapper;import com.example.spring.service.StudentService;@Servicepublic class StudentServiceImpl implements StudentService {@Autowiredprivate StudentMapper studentMapper;@Overridepublic List<Student> findAll() {String sql = "SELECT * FROM tb_student";return studentMapper.operateReturnBeans(sql);}}

其中，注解@Service对应的是业务层Bean

关于注解，可参考：Spring常用注解官方释义

其他参考：

http://blog.csdn.net/jbjwpzyl3611421/article/details/18700335

http://www.cnblogs.com/xdp-gacl/p/3495887.html

student.jsp:

<%@ page language="java" contentType="text/html; charset=UTF-8"pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Insert title here</title></head><body><c:forEach items="${result}" var="item">          ${item.id}--${item.name}--${item.age}--${item.major}<br /></c:forEach></body></html>

其中，<c:forEach>是JSTL语法，在controller中map.put("result", result);里面的内容传过来，这样就可解析出”result"内容了。
运行结果：

参考：Spring MVC整合Mybatis实例    demo源码