java - 多部分表单 POST 提交请求获取损坏的文件

Question

我无法正确上传文件。

我的问题摘要:任何正在上传的文件(*.docx、*.pdf、*.jpg/png/bmp 等)在服务器端收到时都是损坏的。

我的环境:JSP + Spring 3 MVC + Java。

我尝试了不同的方法，包括 here 建议的一种方法由 BalusC，但失败了。

这些是严重失败的示例上传。

我的代码: tempform.jsp

<form:form method="POST" acceptCharset="ISO-8859-15" action="submit.htm"
commandName="commandform" enctype="multipart/form-data" >
...
<input  name ="file0[] type="file" id="file0" multiple>
...
<input type="submit" name="submit">

controller.java

@RequestMapping(value = "/submit", method = RequestMethod.POST)
public ModelAndView submitRequest(@ModelAttribute("commandform") Request req, HttpServletRequest request, HttpServletResponse response, ModelMap model){
try {
 MultipartHttpServletRequest tempPart = (MultipartHttpServletRequest) httpReq;
         //file being transported is original.jpg and is only one.
         MultipartFile filePart = tempPart.getFile("file0[]");
         String fileName1 = filePart.getOriginalFilename();
         InputStream fileContent = filePart.getInputStream();

         //printing file here in this step for debugging purpose. Using jpg type only for example purpose.
         BufferedImage bImageFromConvert = ImageIO.read(fileContent);
         ImageIO.write(bImageFromConvert, "jpg", new File(
                "e:/mynewfile.jpg"));
         //file is created at location but with distorted version as shown in image.
         ...
}catch(Exception ex){
...
}
}

我的疑问:内容类型是否对这种行为负责？我在逼CharacterEncodingFilter与 <init-param>值为 ISO-8859-15在我的 web.xml .我用过ISO-8859-15 jsp 页面中的编码也是如此，因为我也必须处理欧洲文本。欢迎任何帮助或指导。提前致谢。

Answer 1

我不认为问题出在 acceptCharset="ISO-8859-15"
我根据 Spring IO 网站上的入门指南整理了一个测试用例(使用 Spring boot spring-boot):Spring IO file upload example

我还为工作中的一个文件上传项目编写了一个 Spring 3 MVC Controller 。它类似于我在下面显示的示例。

使用这个 Spring boot 测试用例，我可以使用 UTF-8 和 ISO-8859-15 上传您的示例图像。它工作正常。当然，我没有像您一样使用 CharacterEncodingFilter。
这是我的一些代码，因此您可以与您的代码进行比较。

希望对你有所帮助。

应用程序.java:

@Configuration
@ComponentScan
@EnableAutoConfiguration
public class Application extends SpringBootServletInitializer {

    @Bean
    public MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        factory.setMaxFileSize("128KB");
        factory.setMaxRequestSize("128KB");
        return factory.createMultipartConfig();
    }

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(Application.class);
    }

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

文件上传 Controller .java:

@Controller
public class FileUploadController {

    @RequestMapping("/")
    public String welcome() {
        return "welcome";
    }

    @RequestMapping(value="/upload", method=RequestMethod.GET)
    public @ResponseBody String provideUploadInfo() {
        return "You can upload a file by posting to this same URL.";
    }

    @RequestMapping(value="/upload", method=RequestMethod.POST)
    public @ResponseBody String handleFileUpload(@RequestParam("name") String name, 
            @RequestParam("file") MultipartFile file){
        if (!file.isEmpty()) {
            try {
                byte[] bytes = file.getBytes();
                BufferedOutputStream stream = 
                        new BufferedOutputStream(new FileOutputStream(new File(name)));
                stream.write(bytes);
                stream.close();
                return "You successfully uploaded " + name + " into " + name;
            } catch (Exception e) {
                return "You failed to upload " + name + " => " + e.getMessage();
            }
        } else {
            return "You failed to upload " + name + " because the file was empty.";
        }
    }
}

welcome.jsp 片段:

<%-- 
<form:form action="upload" method="POST" acceptCharset="UTF-8" enctype="multipart/form-data"  >
--%>
<form:form action="upload" method="POST" acceptCharset="ISO-8859-15" enctype="multipart/form-data"  >
  <table>
      <tr>
        <td>  
            <!-- <input type="hidden" name="action" value="upload" />  -->
            <strong>Please select a file to upload :</strong> <input type="file" name="file" />
        </td>
      </tr>
      <tr>
        <td>Name: <input type="text" name="name"><br />
        </td>
      </tr>
      <tr>
        <td>
         <input type="submit" value="Upload"> Press here to upload the file!
        </td>
      </tr>
  </table>
</form:form>