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

小咪咪 2022-03-18 01:14 83阅读 0赞

1、工程结构：

![1365173321_3041.png][]

spring mvc的访问地址是使用REST风格

![1365173660_4189.png][]

2、web.xml的配置

<servlet>
      	<servlet-name>hello</servlet-name>
      	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      	<init-param>
      		<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.xsd
    		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">
    	
    	
    	<mvc:annotation-driven/>
    	
    	
    	<mvc:resources location="/resources/" mapping="/resources/**"/>
    	
    	
    	<context:component-scan base-package="cn.edu.hj.controller"></context:component-scan>
    	
    	
    	<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    		<property name="prefix" value="/WEB-INF/jsp/"></property>
    		<property name="suffix" value=".jsp"></property>
    	</bean>
    	
    	
    	<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][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", "ldh@qq.com"));
    		users.put("gfc",new User("gfc", "123", "gfc@qq.com"));
    		users.put("zxy",new User("zxy", "123", "zxy@qq.com"));
    		users.put("lm ",new User("lm ", "123", " lm@qq.com"));
    	}
    	/**
    	 * 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

【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>

![1365173939_2753.png][]

【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" %>
        
        <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>

![1365174032_5953.png][]  
【5】/WebRoot/WEB-INF/jsp/user/show.jsp页面  用于显示某个用户信息的

![1365174109_9937.png][]

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

<body>
        
        <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>

![1365174226_2281.png][]

【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>

![1365174294_1629.png][]  
整个工程的下载地址为： [http://download.csdn.net/detail/wxwzy738/5224307][http_download.csdn.net_detail_wxwzy738_5224307]

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[1365173660_4189.png]: https://img-my.csdn.net/uploads/201304/05/1365173660_4189.png
[http_www.ibm.com_developerworks_cn_java_j-lo-jsr303_index.html]: http://www.ibm.com/developerworks/cn/java/j-lo-jsr303/index.html
[1365173939_2753.png]: https://img-my.csdn.net/uploads/201304/05/1365173939_2753.png
[1365174032_5953.png]: https://img-my.csdn.net/uploads/201304/05/1365174032_5953.png
[1365174109_9937.png]: https://img-my.csdn.net/uploads/201304/05/1365174109_9937.png
[1365174226_2281.png]: https://img-my.csdn.net/uploads/201304/05/1365174226_2281.png
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[http_download.csdn.net_detail_wxwzy738_5224307]: http://download.csdn.net/detail/wxwzy738/5224307