本文介绍了使用Spring表单在Spring MVC中无法上传文件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个jsp页面，在其中使用了spring form标签，以便可以使用model属性并将数据绑定到它.提交表单时工作正常，但是在添加enctype="multipart/form-data"模型属性后，该属性对控制器重现了null.这是怎么了?我的代码是- proflie.jsp
I have a jsp page in which i have used spring form tag so that i can use model attribute and bind data to it. It was working fine on submit the form but after adding enctype="multipart/form-data" model attributes are returing null to the controller. What is wrong here ?My Code is -proflie.jsp
<sf:form method="POST" action="update" modelAttribute="user" class="form-horizontal" >
<div class="form-group">
<label for="inputEmail3" class="col-sm-2 control-label">Avatar</label>
<div class="col-md-6">
<div class="media v-middle">
<div class="media-left">
<div class="icon-block width-100 bg-grey-100">
<i class="fa fa-photo text-light"></i>
</div>
</div>
<div class="media-body">
<i class="fa fa-upl"><sf:input path="imageFile" type="file" class="btn btn-white btn-sm paper-shadow relative" placeholder="Add Image" id="imageFile" />
</i>
</div>
</div>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="col-md-2 control-label">Full Name</label>
<div class="col-md-8">
<div class="row">
<div class="col-md-6">
<div class="form-control-material">
<sf:input path="firstName" type="text" class="form-control" id="firstName" placeholder="Your first name" value="${user.firstName}" />
<sf:input path="id" type="hidden" class="form-control" id="id" value="${user.id}" />
<label for="firstName">First name</label>
</div>
</div>
<div class="col-md-6">
<div class="form-control-material">
<sf:input path="lastName" class="form-control" id="lastName" placeholder="Your last name" value="${user.lastName}" />
<label for="lastName">Last name</label>
</div>
</div>
</div>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="col-md-2 control-label">Email</label>
<div class="col-md-6">
<div class="form-control-material">
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-envelope"></i></span>
<sf:input path="email" type="email" class="form-control" id="inputEmail3" placeholder="Email" value="${user.email}" />
<label for="inputEmail3">Email address</label>
</div>
</div>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="col-md-2 control-label">Phone</label>
<div class="col-md-6">
<div class="form-control-material">
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-envelope"></i></span>
<sf:input path="phone" type="number" class="form-control" id="inputEmail3" placeholder="Phone" value="${user.phone}" />
<label for="phone">Phone</label>
</div>
</div>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="col-md-2 control-label">Address</label>
<div class="col-md-6">
<div class="form-control-material">
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-link"></i></span>
<sf:input path="address" type="text" class="form-control used" id="website" placeholder="Address" value="${user.address}" />
<label for="address">Address</label>
</div>
</div>
</div>
</div>
<div class="form-group">
<label for="inputPassword3" class="col-md-2 control-label">Change Password</label>
<div class="col-md-6">
<div class="form-control-material">
<sf:input path="password" type="password" class="form-control" id="inputPassword3" placeholder="Password" value="${user.password}" />
<label for="password">Password</label>
</div>
</div>
</div>
<div class="form-group margin-none">
<div class="col-md-offset-2 col-md-10">
<button type="submit" class="btn btn-primary paper-shadow relative" data-z="0.5" data-hover-z="1" data-animated>Save Changes</button>
</div>
</div>
</sf:form>
AccountController类
package com.vc.teacher.controller;
import java.io.File;
import org.apache.commons.io.FileUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
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.servlet.mvc.support.RedirectAttributes;
import com.vc.teacher.db.dao.UserDao;
import com.vc.teacher.entities.User;
import com.vc.teacher.util.Constants;
@Controller
public class AccountController {
@Autowired
UserDao userDao;
@RequestMapping("/login")
public String loginUser(@RequestParam("email") String email,
@RequestParam("password") String password, Model model) {
User user = userDao.checkCreditionals(email, password);
if (user != null) {
model.addAttribute("user", user);
return "jsp/profile";
} else {
model.addAttribute("error", "Wrong creditionals");
return "jsp/signin";
}
}
@RequestMapping("/signUp")
public String initilize(Model model) {
model.addAttribute(new User());
return "jsp/signup";
}
@RequestMapping(method = RequestMethod.POST, value = "/register")
public String signUpUser(User user, RedirectAttributes attributes) {
boolean result = false;
File imageFile = null;
try {
imageFile = user.getImageFile();
if (imageFile != null) {
File imageFileSave = new File(Constants.MEDIA_FILE_PATH);
FileUtils.copyFile(imageFile, imageFileSave);
user.setImageFileName(imageFile.getName());
}
user.setStatus("Deactive");
result = userDao.registerUser(user);
if (result == true) {
attributes.addFlashAttribute("message",
"You are ready to go now !");
return "redirect:/signUp";
} else {
attributes.addFlashAttribute("message", "Something went wrong");
return "redirect:/signUp";
}
} catch (Exception e) {
attributes.addFlashAttribute("message", "Something went wrong");
return "redirect:/signUp";
}
}
@RequestMapping(method = RequestMethod.POST, value = "/update")
public String updateUser(User user, RedirectAttributes attributes) {
boolean result = false;
File imageFile = null;
try {
System.out.println("=================================="+user.getEmail());
System.out.println("=================================="+user.getId());
System.out.println("=================================="+user.getFirstName());
imageFile = user.getImageFile();
if (imageFile != null) {
File imageFileSave = new File(Constants.MEDIA_FILE_PATH);
FileUtils.copyFile(imageFile, imageFileSave);
user.setImageFileName(imageFile.getName());
}
user.setStatus("Active");
result = userDao.updateUser(user);
if (result == true) {
attributes.addFlashAttribute("message", "Profile Updated !");
return "jsp/profile";
} else {
attributes.addFlashAttribute("message", "Something went wrong");
return "jsp/profile";
}
} catch (Exception e) {
attributes.addFlashAttribute("message", "Something went wrong");
return "jsp/profile";
}
}
}
推荐答案
DispatcherServlet本身不知道如何处理多部分表单数据.这就是为什么我们需要多部分解析器.
On its own, DispatcherServlet doesn't know how to handle multipart form data; that's why we require multipart resolver.
您应该在servlet-config中注册它:
You should register it in your servlet-config:
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<property name="maxUploadSize" value="500000" />
</bean>
在您的User对象中使用CommonsMultipartFile或MultipartFile代替File:
Use CommonsMultipartFile or MultipartFile instead of File in your User object:
private CommonsMultipartFile imageFile;
您可以尝试以下代码来保存文件:
You can try this code to save file:
File imageFileSave = new File(Constants.MEDIA_FILE_PATH);
FileUtils.writeByteArrayToFile(imageFileSave , imageFile.getBytes());
这篇关于使用Spring表单在Spring MVC中无法上传文件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！