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

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

分类： spring2013-04-05 23:03 865人阅读 评论(1) 收藏 举报

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./schema/beans"
    xmlns:xsi="http://www./2001/XMLSchema-instance"
    xmlns:context="http://www./schema/context"
    xmlns:mvc="http://www./schema/mvc"
    xsi:schemaLocation="http://www./schema/mvc http://www./schema/mvc/spring-mvc-3.1.xsd
        http://www./schema/beans http://www./schema/beans/spring-beans-3.0.xsd
        http://www./schema/context http://www./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;
    }
    @Override
    public 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user
        return "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/jpeg
        System.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>
lt;%@taglib prefix="sf" uri="http://www./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