spring、springmvc、mybatis整合笔记
这段时间上一个项目刚做完，下一个项目还没开始，趁这个时候来认真总结一下上个项目使用的ssm开发框架。由于，项目中关于使用ssm这部分的代码和配置是我们项目的整体架构师一个独立完成的，我们只负责业务部分的代码，调用他写好的后台，所以涉及到ssm具体使用的我都没参与，之前简单的做过s（struts）sh，对于ssm不是很熟悉，所以，这段时间从头到尾独立搭建一个ssm框架的web应用。
首先，spring、springmvc、mybatis所需要的jar包准备好，导入到新建web项目的lib中，然后开始搭建java源代码（src）下的结构，我在这里用到的是类似ssh的结构mapper.java、mapper.xml、dao、daoImpl、service、serviceImpl、controller。项目目录结构如下。
接下来，写配置文件。
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_3_0.xsd" id="WebApp_ID" version="3.0"> <display-name>SSM</display-name> <!-- spring配置文件加载 --> <context-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:resources/spring-config.xml</param-value> </context-param> <!-- Spring ApplicationContext 载入 --> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- mvc控制器 --> <servlet> <servlet-name>dispatcher</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value> classpath:resources/mvc-config.xml </param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>dispatcher</servlet-name> <url-pattern>*.do</url-pattern> </servlet-mapping> <!-- 默认显示的首页面 --> <welcome-file-list> <welcome-file>login.html</welcome-file> <welcome-file>login.jsp</welcome-file> </welcome-file-list> </web-app>
-----------------------------------------------spring.xml--------------------------------------
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd"> <!-- 扫描DAO和SERVICE包，controller包在springmvc中扫描 --> <context:component-scan base-package="com.liusk.serviceImpl,com.liusk.daoImpl" /> <!-- 数据源 --> <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="com.mysql.jdbc.Driver"></property> <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/ssm?characterEncoding=utf-8"></property> <property name="user" value="root"></property> <property name="password" value="java"></property> <property name="minPoolSize" value="5"></property> <property name="maxPoolSize" value="100"></property> </bean> <!-- 会话工厂 --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"></property> <property name="configLocation" value="classpath:resources/mybatis-config.xml"></property> <property name="mapperLocations" value="classpath:com/liusk/mapper/*.xml"></property> </bean> <!-- 事务处理 --> <bean id="txManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"></property> </bean> <tx:advice id="txAdvice" transaction-manager="txManager"> <tx:attributes> <tx:method name="insert*" propagation="REQUIRED"></tx:method> <tx:method name="delete*" propagation="REQUIRED"></tx:method> <tx:method name="update*" propagation="REQUIRED"></tx:method> <tx:method name="select*" propagation="SUPPORTS"></tx:method> </tx:attributes> </tx:advice> <aop:config> <aop:pointcut id="serviceCut" expression="execution(public * com.liusk.service.*.*(..))" /> <aop:advisor pointcut-ref="serviceCut" advice-ref="txAdvice" /> </aop:config> <!-- spring和mybatis的整合 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.liusk.mapper"/> </bean> </beans>
关于spring和mybatis整合的方法有很多种，上面xml中是最基础的配置，还可以加入其它的限制条件，这个可以单独到百度上搜更详细的解释。
-------------------------------------------------------mvc-config.xml------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:context="http://www.springframework.org/schema/context" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"> <!-- 扫描controller包 --> <context:component-scan base-package="com.liusk.controller"></context:component-scan> <!-- 完成请求和注解POJO的映射 --> <bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"/> <!-- 页面转向解析 --> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/" /> <property name="suffix" value=".jsp" /> </bean> <!-- 支持文件上传 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> </bean> </beans>
在mvcconfig中，最重要的工作是控制转发，这个配置文件中做了最简单的转发操作，只能转发页面，如果想要通过ajax实现转发数据，那么需要重写ViewResolver来实现这个功能。
--------------------------------------------------------mybatis-config.xml-------------------------------------
<?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> <!-- 定义别名 --> <typeAliases> <typeAlias type="com.liusk.entity.User" alias="User"/> </typeAliases> </configuration>
至此，配置文件部分完毕。
下面是src源码
----------------------------------------------------------User.java------------------------------------------------------
package com.liusk.entity; public class User { private String userId; private String username; private String password; public String getUserId() { return userId; } public void setUserId(String userId) { this.userId = userId; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
mybatis的实体类和hibernate实体类的不同是mybatis的实体类不需要加载到spring的beanFactory中，而是通过操作数据库的mapper来持久化数据。
-----------------------------------------------------------UserMapper.java------------------------------------------
package com.liusk.mapper; import java.util.List; import com.liusk.entity.User; public interface UserMapper { public List<User> selectUser(User user); public void insertUser(User user); public List<User> selectUserByUserName(String username); }
UserMapper.java这个文件是在何时被加载到spring中的呢？我们知道它是在daoImpl中使用到的，而且是注解到daoImpl中的，所以它一定在之前已经被加载到beanFactory中了，我在第一次配置的时候也不是太清楚它是什么时候进入beanFactory因为它身上没有任何注解，所以，根据spring配置文件中spring和mybatis的整合，推测UserMapper.java就是在
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="com.liusk.mapper"/></bean>
这个地方被加载的。这个下面有详细解答。
----------------------------------------------------------UserMapper.xml------------------------------------------
<?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.liusk.mapper.UserMapper"> <resultMap type="com.liusk.entity.User" id="userMap"> <id column="user_id" property="userId" ></id> <result column="user_name" property="username"/> <result column="password" property="password"/> </resultMap> <select id="selectUser" parameterType="User" resultType="java.util.List" resultMap="userMap"> select * from user where user_name = #{username} and password = #{password} </select> <select id="selectUserByUserName" parameterType="java.lang.String" resultType="java.util.List" resultMap="userMap"> select * from user where user_name = #{username} </select> <insert id="insertUser" parameterType="User"> insert into user values (#{userId},#{username},#{password}) </insert> </mapper>
该配置文件中namespace对应接口的路径，也就是mapper.java的路径，否则抛出异常。所以这里牵涉到一个问题：UserMapper.java到底是何时加载到beanFactory的？为什么会用这个问题呢，应为UserMapper.xml在spring的sessionFactory初始化的时候被扫描并加载到spring，那么这个时候会不会根据这个命名空间同时把UserMapper.java加载到beanFactory中呢，其实我没有看过spring和mybatis的源码，所以不太了解。根据猜测和验证，UserMapper.java不是在这个时候被加载的。
------------------------------------------------------UserDAO--------------------------------------------
package com.liusk.dao; import java.util.List; import com.liusk.entity.User; public interface UserDAO { public List<User> selectUser(User user); public void insertUser(User user); public List<User> selectUserByUserName(String username); }
这个UserDAO的存在就是在向我的第一个项目使用ssh致敬的，其实这个UserDAO他就是个接口，可以不存在，下面的UserService也是这个道理。
------------------------------------------------------UserDAOImpl----------------------------------------
package com.liusk.daoImpl; import java.util.List; import org.safehaus.uuid.UUIDGenerator; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Repository; import com.liusk.dao.UserDAO; import com.liusk.entity.User; import com.liusk.mapper.UserMapper; @Repository public class UserDAOImpl implements UserDAO { @Autowired private UserMapper userMapper; private UUIDGenerator uuidGen = UUIDGenerator.getInstance(); @Override public List<User> selectUser(User user) { return userMapper.selectUser(user); } @Override public void insertUser(User user) { String userId = uuidGen.generateTimeBasedUUID().toString(); if(user.getUserId()==null||user.getUserId()=="") user.setUserId(userId.replace("-", "")); System.out.println(user.getUserId()); userMapper.insertUser(user); } @Override public List<User> selectUserByUserName(String username) { return userMapper.selectUserByUserName(username); } }
UserDAOImpl和UserServiceImpl类似，都是实现类，做具体的数据持久化操作。
--------------------------------------------------------UserService-----------------------------------------
package com.liusk.service; import java.util.List; import com.liusk.entity.User; public interface UserService { public void insertUser(User user); public List<User> selectUser(User user); public boolean existUser(String username); }
--------------------------------------------------------UserServiceImpl--------------------------------------
package com.liusk.serviceImpl; import java.util.List; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import com.liusk.dao.UserDAO; import com.liusk.entity.User; import com.liusk.service.UserService; @Service public class UserServiceImpl implements UserService{ @Autowired private UserDAO userDAO; @Override public void insertUser(User user) { userDAO.insertUser(user); } @Override public List<User> selectUser(User user) { return userDAO.selectUser(user); } @Override public boolean existUser(String username) { List<User> userList = userDAO.selectUserByUserName(username); if(userList.size()>0) return true; else return false; } }
-------------------------------------------------------UserController-------------------------------------
package com.liusk.controller; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpSession; 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.liusk.base.UserCounts; import com.liusk.entity.User; import com.liusk.service.UserService; @Controller @RequestMapping("user") public class UserController { @Autowired private UserService userService; @SuppressWarnings("rawtypes") @RequestMapping("login.do") public ModelAndView login(String username,String password,HttpServletRequest request){ User user = new User(); user.setUsername(username); user.setPassword(password); List<User> userList = userService.selectUser(user); if(userList.size()>0){ request.setAttribute("userList", userList);return new ModelAndView("index"); }else return new ModelAndView("login"); } @RequestMapping("regist.do") public ModelAndView regist(String username,String password,HttpServletRequest request){ User user = new User(); user.setUsername(username); user.setPassword(password); boolean flag = true; flag = userService.existUser(username); if(!flag) userService.insertUser(user); return new ModelAndView("login"); } }
至此，src下的java源码完毕。
下面是jsp页面部分。
-----------------------------------------------------login.jsp--------------------------------------------------
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <base href=" <%=basePath%>"> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>登录页面</title> </head> <body> <div> <div> <form action="user/login.do" method="post"> <label>用户名：</label> <input type="text" name="username" /> <label>密码:</label> <input type="password" name="password"/> <button type="submit">登录</button> <button type="reset" >重置</button> </form> </div> </div> </body> </html>
-----------------------------------------------------index.jsp--------------------------------------------------------
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="com.liusk.entity.User" %> <%@ page import="java.util.List" %> <% String path = request.getContextPath(); String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; %> <% List<User> userList = (List<User>)request.getAttribute("userList");%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <base href=" <%=basePath%>"/> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>index</title> </head> <body> <div> <p>欢迎<%=userList.get(0).getUsername() %>!</p> </div> <div align="center" style="width:200;height:200"> <form action="user/regist.do" method="post"> <input type="text" name="username"/> <input type="text" name="password"/> <button type="submit">提交</button> <button type="reset">重置</button> </form> </div> </body> </html>
jsp你懂得，这些页面就不做多解释。
总结，会用框架不难，难的是写一个框架出来，有梦就要勇敢飞。
