Question

我有一个jsp，其中包含此代码段。

<form name="AudioFileConversionForm" enctype="multipart/form-data" method="post" >
Choose File: <input type="file" id="audioFile" name="audioFile"><br>
<input type="submit" value="upload">
</form>

这是spring中的控制器。

public String convertFile(HttpServletRequest request, HttpSession session) {

    String audioFile = request.getParameter("audioFile");
    System.out.println(request.getParameter("audioFile"));
    System.out.println("Audio File Conversion Successful");
}

我无法检索文件名，显示null。我知道我可以使用JQuery或javascript检索名称，但我不想同时使用它们。我想用纯java来做。有人可以帮帮我吗？

Answer 1

上传文件时，request是org.springframework.web.multipart.MultipartHttpServletRequest的实例。因此，您可以在方法convertFile()中强制转换它。见下文：

public String convertFile(HttpServletRequest request, HttpSession session) {
    // cast request
    MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
    // You can get your file from request
    CommonsMultipartFile multipartFile =  null; // multipart file class depends on which class you use assuming you are using org.springframework.web.multipart.commons.CommonsMultipartFile

    Iterator<String> iterator = multipartRequest.getFileNames();

    while (iterator.hasNext()) {
        String key = (String) iterator.next();
        // create multipartFile array if you upload multiple files
        multipartFile = (CommonsMultipartFile) multipartRequest.getFile(key);
    }

    // logic for conversion
}

但是我无法检索（接收空值）我在JSP页面中选择的文件的名称。

---＆GT;要获取文件名，您可以将其命名为：

multipartFile.getOriginalFilename();  // get filename on client's machine
multipartFile.getContentType();       // get content type, you can recognize which kind of file is, pdf or image or doc etc
multipartFile.getSize()          // get file size in bytes

要使文件上传工作，您需要确保创建多部分解析器bean，如下所示：

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver">

    <!-- one of the properties available; the maximum file size in bytes -->
    <property name="maxUploadSize" value="100000"/>
</bean>

参考：Spring documentation

Answer 2

使用MultipartFile实用程序并尝试此

MultipartRequest multipartRequest = (MultipartRequest) request;
                Map map = multipartRequest.getFileMap();
                MultipartFile mfile = null;
                for (Iterator iter = map.values().iterator(); iter.hasNext();) {
                    mfile = (MultipartFile) iter.next();
                                String fileName = mfile.getOriginalFilename()
    }

或者你可以试试apache commons文件上传。

点击此链接：http://commons.apache.org/fileupload/using.html

Answer 3

无法直接检索文件名。您可以使用Apache Commons Fileupload API -

// Create a factory for disk-based file items
FileItemFactory factory = new DiskFileItemFactory();

// Create a new file upload handler
ServletFileUpload upload = new ServletFileUpload(factory);

// Parse the request
List /* FileItem */ items = upload.parseRequest(request);
// Process the uploaded items
Iterator iter = items.iterator();
while (iter.hasNext()) {
    FileItem item = (FileItem) iter.next();

    if (item.isFormField()) {
       // Process a normal field
       String name = item.getFieldName();
       String value = item.getString();

    } else {
        // Process a file upload field 
    String fileName = item.getName();
    // DO further processing

    }
}

更多细节 -

http://commons.apache.org/fileupload/using.html

它也可以用Java完成，但显然需要更多的代码。

Answer 4

但是，首先，您需要 Commons Fileupload API ，这将帮助您使用file.getFieldName()来显示表单字段名称和{{ 1}}显示文件类型和file.getContentType()以显示文件名

file.getName()

Answer 5

Iterator iter = items.iterator();
while (iter.hasNext()) {
    FileItem item = (FileItem) iter.next();

    if (item.isFormField()) {
       // Process a normal field
       String name = item.getFieldName();
       String value = item.getString();

    } else {
        // Process a file upload field 
    String fileName = item.getName();
    // DO further processing

    }
}

使用文件类型输入时检索文件名

5 个答案: