spring mvc
这个示例通过一个spring mvc用户登录的示例来学习是如何进行spring web开发的。
业务功能：用户通过登录页面输入用户名和密码，提交验证，登录成功则更新用户登录信息（登录ip,最后访问时间，积分+5)同时记录用户登录成功日志。整个demo分为四层，每层对应一个对立的配置文件。
持久层对象，也是域对象也叫实体。
持久层：spring整合多种流行ORM框架，如hibernate,ibatis等，此demo采用spring JDBC，通过调用org.springframework.jdbc.core.JdbcTemplate完成DAO的实现。配置文件命名(app-dao.xml)
业务层：以接口的方式，调用持久层DAO。接口的方式可增加代码的灵活性，同时有利于项目的管理以及变更。配置文件命名(app-service.xml)
表现层：采用spring mvc框架。层次与struts类似，不过要手动配置Spring MVC地址映射，控制器，以及URL与控制器映射定义。个人认为初次配置觉得较struts而言麻烦点，但很灵活。可以通过配置手动配置请求地址，响应地址。关于整个demo将上传，下面解释下各配置文件。
1.在spring中装配DAO(这里以userlogin-dao.xml为例)
- <?xml version="1.0" encoding="UTF-8"?>
- <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd" >
- <beans>
- <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
- <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
- <property name="url" value="jdbc:mysql://localhost:3306/test"/>
- <property name="username" value="root"/>
- <property name="password" value="root"/>
- </bean>
- <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate">
- <property name="dataSource" ref="dataSource"/>
- </bean>
- <bean id="userDao" class="com.me.dao.imp.UserDaoImp">
- <property name="jdbcTemplate" ref="jdbcTemplate"/>
- </bean>
- <bean id="userLogDao" class="com.me.dao.imp.UserLogDaoImp">
- <property name="jdbcTemplate" ref="jdbcTemplate"/>
- </bean>
- </beans>
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd" > <beans> <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close"> <property name="driverClassName" value="com.mysql.jdbc.Driver"/> <property name="url" value="jdbc:mysql://localhost:3306/test"/> <property name="username" value="root"/> <property name="password" value="root"/> </bean> <bean id="jdbcTemplate" class="org.springframework.jdbc.core.JdbcTemplate"> <property name="dataSource" ref="dataSource"/> </bean> <bean id="userDao" class="com.me.dao.imp.UserDaoImp"> <property name="jdbcTemplate" ref="jdbcTemplate"/> </bean> <bean id="userLogDao" class="com.me.dao.imp.UserLogDaoImp"> <property name="jdbcTemplate" ref="jdbcTemplate"/> </bean> </beans>
这里主要想说的的是jdbcTemplate，因为此demo采用spring JDBC实现的持久层，而spring JdbcTemplate封装了jdbc的操作，本身只需要一个DataSource.
2.配置业务层(这里以userlog-service.xml为例)
...
- <beans>
- <!--事务管理器：对目标类方法进行事务管理-->
- <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
- <property name="dataSource" ref="dataSource"/>
- </bean>
- <!--需要代理哦业务目标类-->
- <bean id="userServiceTarget" class="com.me.service.imp.UserServiceImp">
- <property name="userDao" ref="userDao"/>
- <property name="logDao" ref="userLogDao"></property>
- </bean>
- <!--配置声明式事务-->
- <bean id="userService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
- <property name="transactionManager" ref="transactionManager"></property>
- <property name="target" ref="userServiceTarget"/>
- <!--声明式事务的规则，属性、值-->
- <property name="transactionAttributes">
- <props>
- <prop key="findUserByUserName">
- PROPAGATION_REQUIRED,readOnly
- </prop>
- <prop key="checkUser">PROPAGATION_REQUIRED,readOnly</prop>
- <prop key="loginSuccess">PROPAGATION_REQUIRED</prop>
- </props>
- </property>
- </bean>
- </beans>
<beans> <!--事务管理器：对目标类方法进行事务管理--> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!--需要代理哦业务目标类--> <bean id="userServiceTarget" class="com.me.service.imp.UserServiceImp"> <property name="userDao" ref="userDao"/> <property name="logDao" ref="userLogDao"></property> </bean> <!--配置声明式事务--> <bean id="userService" class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean"> <property name="transactionManager" ref="transactionManager"></property> <property name="target" ref="userServiceTarget"/> <!--声明式事务的规则，属性、值--> <property name="transactionAttributes"> <props> <prop key="findUserByUserName"> PROPAGATION_REQUIRED,readOnly </prop> <prop key="checkUser">PROPAGATION_REQUIRED,readOnly</prop> <prop key="loginSuccess">PROPAGATION_REQUIRED</prop> </props> </property> </bean> </beans>
大家知道凡是操作数据库都要涉及到事务处理，而利用spring我们将不用在代码实现中担心这一点，通过spring声明式事务配置即可。这里需要额外提一下transactionAttributes是定义目标业务类那些方法需要业务的支持以及事务控制属性。PROPAGATION_REQUIED是用得最多的事务传播类型，表示业务方法在当前线程中查看是否有事务，如果有，就利用这个事务，否则就创建一个新事务。readOnly表示是只读事务，可以提高运行效率。此外，在配置方法名时，可实用“*”，不过不指定方法就表示对所有方法进行事务管理。
3.配置Spring MVC 框架
1）修改web.xml,以便web容器启动时自动启动Spring容器。
- <context-param>
- <param-name>contextConfigLocation</param-name>
- <param-value>classpath:userlogin-dao.xml,classpath:userlog-service.xml</param-value>
- </context-param>
- <listener>
- <listener-class>
- org.springframework.web.context.ContextLoaderListener
- </listener-class>
- </listener>
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:userlogin-dao.xml,classpath:userlog-service.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
2）配置spring mvc地址映射，与struts一样，spring mvc也需要一个servlet截获URL,修改web.xml.
- <servlet>
- <servlet-name>userlogin</servlet-name>
- <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
- <load-on-startup>2</load-on-startup>
- </servlet>
- <servlet-mapping>
- <servlet-name>userlogin</servlet-name>
- <url-pattern>*.html</url-pattern>
- </servlet-mapping>
<servlet>
<servlet-name>userlogin</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>2</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>userlogin</servlet-name>
<url-pattern>*.html</url-pattern>
</servlet-mapping>
需要说明的像struts一样,spring也需要一个类似struts-config.xml的配置文件，但命名可有讲究的哦，要采用<servlet-name>-servlet.xml以这个例子来说则需要在/WEB-INF目录下创建一个userlogin-servlet.xml,但这个配置文件无需在web.xml配置上下文参数，因为spring mvc的servlet会自动将userlogin-servlet.xml与spring其他配置文件（userlogin-dao.xml,userlog-service.xml）进行拼装。
3）在配置文件中声明控制器(userlogin-servlet.xml)
- <beans>
- <bean name="loginController" class="com.me.web.LoginController">
- <property name="userService" ref="userService"></property>
- </bean>
- <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
- <property name="mappings">
- <props>
- <prop key="/loginController.html">loginController</prop>
- </props>
- </property>
- </bean>
- <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
- <property name="prefix" value="/jsp/"/>
- <property name="suffix" value=".jsp"/>
- </bean>
- </beans>
<beans> <bean name="loginController" class="com.me.web.LoginController"> <property name="userService" ref="userService"></property> </bean> <bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping"> <property name="mappings"> <props> <prop key="/loginController.html">loginController</prop> </props> </property> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/jsp/"/> <property name="suffix" value=".jsp"/> </bean> </beans>
这个配置说明/loginController.html的请求将交由loginController类处理，处理结果返回一个ModelandView("param1","param2",param3)对象，带有三个参数，分别表示重定向视图逻辑名，保存在request范围内的一个变量名，变量的值。而viewResolver中就是在配置重定向的页面，它的url是：prefix+parma1+suffix.此demo中登录成功后将重定向到{basepath}/jsp/main.jsp
最后处理下乱码问题。此demo采用的是uft-8的字符编码，后来还是出现了乱码，于是调用spring 中的过滤器进行过滤。修改web.xml.
- <filter>
- <filter-name>encodingFilter</filter-name>
- <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
- <init-param>
- <param-name>encoding</param-name>
- <param-value>utf8</param-value>
- </init-param>
- </filter>
- <filter-mapping>
- <filter-name>encodingFilter</filter-name>
- <url-pattern>/jsp/*</url-pattern>
- </filter-mapping>
- <filter-mapping>
- <filter-name>encodingFilter</filter-name>
- <url-pattern>*.html</url-pattern>
- </filter-mapping>
- <filter-mapping>
- <filter-name>encodingFilter</filter-name>
- <url-pattern>*.jsp</url-pattern>
- </filter-mapping>
<filter>
<filter-name>encodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>utf8</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/jsp/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>*.html</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>*.jsp</url-pattern>
</filter-mapping>
初次接触spring mvc,还在学习。将上传此demo与大家分享、探讨。
package com.me.web;
import java.util.Date;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.validation.BindException;
import org.springframework.web.servlet.ModelAndView;
//import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.mvc.AbstractCommandController;
import com.me.entity.User;
import com.me.service.UserService;
import com.me.web.LoginCommand;
public class LoginController extends AbstractCommandController {
private UserService userService;
public LoginController(){
this.setCommandClass(LoginCommand.class);
}
@Override
protected ModelAndView handle(HttpServletRequest req,
HttpServletResponse res, Object command, BindException e)
throws Exception {
LoginCommand loginCommand = (LoginCommand)command;
System.out.print("username="+loginCommand.getUsername());
if(userService.checkUser(loginCommand.getUsername(),loginCommand.getPassword())){
User user = userService.findUserByUserName(loginCommand.getUsername());
user.setLastIP(req.getLocalAddr());
user.setLastVisit(new Date());
userService.loginSuccess(user);
req.getSession().setAttribute("user", user);
return new ModelAndView("main");
}else{
//用户不存在�û�������
return new ModelAndView("login","error","用户名或密码错误");
}
}
public void setUserService(UserService userService) {
this.userService = userService;
}
}
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%>
<%@ taglib uri="/WEB-INF/c.tld" prefix="c"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<base href="<%=basePath%>">
<meta http-equiv="content-type" content="text/html; charset=utf-8">
<title>Spring 鐧诲綍</title>
</head>
<body>
<br/>
<c:if test="${!empty error}">
<font color="red">${error}</font>
</c:if>
<form action="<c:url value="/loginController.html"/>" method="post">
鐢ㄦ埛鍚嶏細<input type="text" name="username" /><br/>
瀵? 鐮侊細<input type="password" name="password"/><br/>
<input type="submit" name="btn" value="鐧诲綍"/>
</form>
</body>
</html>
<%@ page language="java" 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">
<html>
<head>
<base href="<%=basePath%>">
<title>鐧诲綍鎴愬姛</title>
</head>
<body>
鎭枩${user.username}鎴愬姛鐧诲綍锛屾偍鐜板湪鐨勭Н鍒嗘槸锛?{user.credits }
</body>
</html>
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" "http://www.springframework.org/dtd/spring-beans-2.0.dtd" >
<beans>
<bean name="loginController" class="com.me.web.LoginController">
<property name="userService" ref="userService"></property>
</bean>
<bean id="urlMapping" class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
<property name="mappings">
<props>
<prop key="/loginController.html">loginController</prop>
</props>
</property>
</bean>
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/jsp/"/>
<property name="suffix" value=".jsp"/>
</bean>
</beans>