二、spring mvc模拟用户增删改查以及登录和上传文件的相关流程

1、工程结构：

spring mvc的访问地址是使用REST风格

2、web.xml的配置

  <servlet>  <servlet-name>hello</servlet-name>  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  <init-param><!-- 这两行是重新定位spring的配置文件路径，默认是在WEB-INF下面的hello-servlet.xml -->  <param-name>contextConfigLocation</param-name>  <param-value>WEB-INF/web-main.xml</param-value>  </init-param>  </servlet>  <servlet-mapping>  <servlet-name>hello</servlet-name>  <url-pattern>*.htm</url-pattern>  </servlet-mapping>

3、书写spring配置文件 /WebRoot/web-main.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:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsdhttp://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsdhttp://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd"><!-- 开始spring mvc的注解 --><mvc:annotation-driven/><!-- 这样根目录下面的resource的文件(.css,.js等)就不会被spring的DispatchServlet进行过滤 --><mvc:resources location="/resources/" mapping="/resources/**"/><!-- 配置注解扫描的包路径 --><context:component-scan base-package="cn.edu.hj.controller"></context:component-scan><!-- 配置action中返回的视图配置  --><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="prefix" value="/WEB-INF/jsp/"></property><property name="suffix" value=".jsp"></property></bean><!-- 上传文件时需要做的配置 --><bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"><property name="maxUploadSize" value="5000000"></property></bean></beans>

4、操作中涉及到的一个User javabean

详细的注解验证可看这个

JSR 303 - Bean Validation 介绍及最佳实践http://www.ibm.com/developerworks/cn/java/j-lo-jsr303/index.html

package cn.edu.hj.bean;import javax.validation.constraints.Size;import org.hibernate.validator.constraints.Email;import org.hibernate.validator.constraints.NotEmpty;/** * 这里属性的get方法上面的注解是spring mvc的验证注解,在actioin中调用 * @author user */public class User {private String username;private String password;private String email;public User(){}public User(String username, String password, String email) {this.username = username;this.password = password;this.email = email;}@NotEmpty(message = "用户名不能为空")public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}@NotEmpty(message = "密码不能为空")@Size(min = 4, max = 8, message = "密码在4~8位之间")public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}@NotEmpty(message = "email不能为空")@Email(message = "email格式不正确")public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}@Overridepublic String toString(){return username+"#"+password+"#"+email;}}

5、模拟用户增删改查以及登录和上传文件的action处理类

package cn.edu.hj.controller;import java.io.File;import java.io.IOException;import java.util.LinkedHashMap;import java.util.Map;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpSession;import javax.validation.Valid;import org.apache.commons.io.FileUtils;import org.springframework.stereotype.Controller;import org.springframework.ui.Model;import org.springframework.validation.BindingResult;import org.springframework.web.bind.annotation.ExceptionHandler;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.ResponseBody;import org.springframework.web.bind.annotation.SessionAttributes;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.servlet.mvc.support.RedirectAttributes;import cn.edu.hj.bean.User;@Controller@RequestMapping(value = "/user")//写上这个注解的话那么在Model中进行添加key为loginUser的时候会默认添加到session中@SessionAttributes(value = "loginUser")public class UserController {Map<String,User> users = new LinkedHashMap<String,User>();public UserController(){//无参数的构造方法会默认被调用一次System.out.println("初始化....");users.put("ldh",new User("ldh", "123", "[e-mail]"));users.put("gfc",new User("gfc", "123", "[e-mail]"));users.put("zxy",new User("zxy", "123", "[e-mail]"));users.put("lm ",new User("lm ", "123", " [e-mail]"));}/** * 初始化user列表信息 * @param model * @param user */public void init(Model model,User user){if(user != null){users.put(user.getUsername(), user);}model.addAttribute("users", users);}/** * 跳转到list页面 * @param model * @return */@RequestMapping(value = "/list.htm")public String list(Model model){init(model, null);return "user/userlist";}/** * 跳转到添加页面 * @return */@RequestMapping(value = "/add.htm", method = RequestMethod.GET)//使用get方法的时候public String add(Model model){//因为在页面上有个modelAttribute="user" user对象，所以要传递一个空的过去，否则报错model.addAttribute(new User());//默认的键为值的类型,为userreturn "user/adduser";}/** * 执行添加操作,并跳转到list页面 * @param user 如果要验证前面需要加上@Valid注解 * @param binding 这个是在验证的时候把信息跟该类进行绑定,可以得到验证的结果信息 * binding的参数必须要放在要验证的那个对象之后 * @param model  * @return */@RequestMapping(value = "/add.htm", method = RequestMethod.POST)//使用post方法的时候public String add(@Valid User user,BindingResult binding,Model model){if(binding.hasErrors()){return "user/adduser";}init(model, user);return "redirect:/user/list.htm";}/** * 根据username得到user对象 * 路径为：/springmvc/user/ldh.htm * @param username前面加上@PathVariable表示路径变量,会跟@RequestMapping的{username}进行对应 * @param model * @return */@RequestMapping(value = "/{username}.htm",method = RequestMethod.GET)public String show(@PathVariable String username,Model model){User user = users.get(username);model.addAttribute("user", user);return "user/show";}/** * 做删除操作,url类似REST风格 * @param username * @return */@RequestMapping(value = "/delete/{username}.htm",method = RequestMethod.GET)public String delete(@PathVariable String username){users.remove(username);return "redirect:/user/list.htm";}/** * 根据username得到user转到更新jsp页面 * @param username * @return */@RequestMapping(value = "/update/{username}.htm",method = RequestMethod.GET)public String update(@PathVariable String username,Model model){User user = users.get(username);model.addAttribute("user", user);return "user/adduser";}/** * 做更新操作,url类似REST风格 * @param user * @return */@RequestMapping(value = "/update/{username}.htm",method = RequestMethod.POST)public String update(@PathVariable String username,@Valid User user,BindingResult br){if(br.hasErrors()){return "/user/adduser";}users.put(user.getUsername(), user);return "redirect:/user/list.htm";}/** * params = "json"相当于在方法参数中写入@RequestParam String json * 那么访问该视图的话必须是/springmvc/user/{username}.htm?json=.. * 目前tomcat不支持此类型的解析，方法可以进来，但是返回不了 * @param username * @param model * @return */@ResponseBody//加上该注解,可以返回对象而不用是String类型@RequestMapping(value = "/{username}.htm",params = "json")public User showJson(@PathVariable String username,Model model){System.out.println("username:"+username);return users.get(username);}/** * 转到登录界面 * @return */@RequestMapping(value = "/login.htm",method = RequestMethod.GET)public String login(){return "/user/login";}/** * 在登录界面进行登录 * @param username * @param password * @param model * @return */@RequestMapping(value = "/login.htm",method = RequestMethod.POST)public String login(String username,String password,Model model){if(!users.containsKey(username)){throw new RuntimeException("用户名不存在!");}if(!password.equals(users.get(username).getPassword())){throw new RuntimeException("密码不正确");}//存放入session中,因为前面已经加了@SessionAttributes(value = "loginUser")注解model.addAttribute("loginUser", users.get(username));return "redirect:/user/list.htm";}/** * 进行异常的捕获,这里是该action中抛出的RuntimeException都在这个方法进行捕获 * @param ex * @param req * @return */@ExceptionHandler(value = {RuntimeException.class})public String handlerException(Exception ex,HttpServletRequest req){req.setAttribute("ex", ex);//把异常放入request请求中return "error";//转到error页面}/** * 使用重定向来进行传递对象 * @param model * @param ra * @return */@RequestMapping(value = "/redir.htm")public String redir(Model model,RedirectAttributes ra){//model.addAttribute("movie", "海贼王");//使用这种方式在重定向是传递不了的ra.addFlashAttribute("movie", "海贼王");//使用这种可以return "redirect:/user/list.htm";}/** * 跳转到上传页面 * @param photo * @return */@RequestMapping(value = "upload.htm",method = RequestMethod.GET)public String uploadPhoto(){return "user/upload";}/** * 进行单个文件上传 * @param photo 这个参数名需要跟表单中上传的name属性名称一样,否则上传不成功 * @param model * @return */@RequestMapping(value = "upload.htm",method = RequestMethod.POST)public String uploadPhoto(MultipartFile photo,Model model,HttpServletRequest req){System.out.println(photo.getContentType());//文件的类型,image/jpegSystem.out.println(photo.getName());//上传的表单名称System.out.println(photo.getOriginalFilename());//上传的文件名String realpath = req.getSession().getServletContext().getRealPath("/upload/");System.out.println(realpath);//容器的webapp目录下try {FileUtils.copyInputStreamToFile(photo.getInputStream(), new File(realpath + "/" +photo.getOriginalFilename()));} catch (IOException e) {e.printStackTrace();}model.addAttribute("message", "上传成功");return "user/upload";}/** * 进行多个文件上传 * @param photos 这个参数名需要跟表单中上传的name属性名称一样,否则上传不成功 * 在批量上传的时候需要加上这个注解@RequestParam当请求参数a不存在时会有异常发生,可以通过设置属性required=false解决 * @param model * @return */@RequestMapping(value = "uploads.htm",method = RequestMethod.POST)public String uploadPhoto(@RequestParam(required = false)MultipartFile[] photos,Model model,HttpServletRequest req){String realpath = req.getSession().getServletContext().getRealPath("/upload/");try {for(MultipartFile photo : photos){if(photo.isEmpty())continue;//可能会有三个上传表单却不一定三个都进行上传，这样其他的就为空需要判断FileUtils.copyInputStreamToFile(photo.getInputStream(), new File(realpath + "/" +photo.getOriginalFilename()));}} catch (IOException e) {e.printStackTrace();}model.addAttribute("message", "上传成功");return "user/upload";}}

6，相关的jsp页面

【1】/WebRoot/index.jsp页面

  <body>    This is my JSP page. <br>  </body>

【2】/WebRoot/WEB-INF/jsp/error.jsp页面  用于显示错误信息的，action中抛出的异常被在此处显示

  <body>    ${ex.message}  </body>

【3】/WebRoot/WEB-INF/jsp/user/userlist.jsp页面  用于显示用户列表的

  <body>  <a href="add.htm">Add</a>  ${loginUser.username } ${movie }<br/>  <%Map<String,User> users = (Map<String,User>)request.getAttribute("users");  if(users != null){  for(User user : users.values()){  %>    <%=user%>   <a href="<%=user.getUsername()%>.htm">详细</a>   <a href="update/<%=user.getUsername()%>.htm">修改</a>   <a href="delete/<%=user.getUsername()%>.htm">删除</a><br/>  <%  }  }  %>  <a href="login.htm">Login</a><br/>  </body>

【4】/WebRoot/WEB-INF/jsp/user/adduser.jsp页面  用于添加修改用户的

  <body><%@taglib prefix="sf" uri="http://www.springframework.org/tags/form" %>    <!-- 这里form的action没写就是当前的路径 -->    <sf:form method="post" modelAttribute="user">    username:<sf:input path="username"/><sf:errors path="username"/><br/>    password:<sf:password path="password"/><sf:errors path="password"/><br/>    email:<sf:input path="email"/><sf:errors path="email"/><br/>    <input type="submit" />    </sf:form>  </body>

【5】/WebRoot/WEB-INF/jsp/user/show.jsp页面  用于显示某个用户信息的

  <body>  <a href="javascript:history.go(-1);">返回</a><br/>  ${user}  </body>

【6】/WebRoot/WEB-INF/jsp/user/login.jsp页面  用户登录的

  <body>    <!-- 这里form的action没写就是当前的路径 -->    <form method="post" action="login.htm">    username:<input type="text" name="username"/><sf:errors path="username"/><br/>    password:<input type="password" name="password"/><sf:errors path="password"/><br/>    <input type="submit" />    </form>  </body>

【7】/WebRoot/WEB-INF/jsp/user/upload.jsp页面  用户登录的

  <body>    <form method="post" action="uploads.htm" enctype="multipart/form-data">    <input type="file" name="photos"><br/>    <input type="file" name="photos"><br/>    <input type="file" name="photos"><br/>    <input type="submit" />${message }    </form>  </body>

整个工程的下载地址为：http://download.csdn.net/detail/wxwzy738/5224307