用GWT保存上传的文件 [英] save an uploaded file with GWT

问题描述

我使用 org.apache.commons.fileupload 上传。

  public void doPost（HttpServletRequest request，HttpServletResponse response）throws ServletException，IOException {
 
 boolean isMultipart = ServletFileUpload.isMultipartContent（request）; 
 GWT.log（is multipart？+ Boolean.toString（isMultipart），null）; 
 
 ServletFileUpload upload = new ServletFileUpload（）; 
 
尝试{
 FileItemIterator iter = upload.getItemIterator（request）; （iter.hasNext（））{
 FileItemStream item = iter.next（）; 
 
 while（iter.hasNext（）） 
 String name = item.getFieldName（）; 
 InputStream stream = item.openStream（）; 
 $ b / ** 
 *保存上传的文件
 * / 
 
} 
} 
 catch（Exception e）{ 
 e.printStackTrace（）; 
 
 
  

如何保存上传的文件？

解决方案

我认为这可以帮助您。

  if（！item.isFormField（））{
 String fieldName = item.getFieldName（）; 
 String fileName = item.getName（）; 
 String contentType = item.getContentType（）; 
 boolean isInMemory = item.isInMemory（）; 
 long sizeInBytes = item.getSize（）; 
 
文件saveTo = new File（/ file_uploads /+ fileName）; 
尝试{
 item.write（saveTo）; 
 ... 
} 
 catch（Exception e）{
 ... 
} 
   
 
 
您可以设置文件的大小阈值保存在磁盘上或使用 
 
 
 创建一个基于磁盘的文件项的工厂
 DiskFileItemFactory factory = new DiskFileItemFactory（）; 
 
 //设置工厂约束
 factory.setSizeThreshold（yourMaxMemorySize）; 
 factory.setRepository（yourTempDirectory）; 
 
 //创建一个新的文件上传处理程序
 ServletFileUpload upload = new ServletFileUpload（factory）; 
 
 //设置总体请求大小约束
 upload.setSizeMax（yourMaxRequestSize）; 
 
 //解析请求
 List / * FileItem * / items = upload.parseRequest（request）; 
  
您需要了解org.apache.commons.fileupload的所有信息如下：使用FileUpload  
 
I am using org.apache.commons.fileupload to upload.
public void doPost(HttpServletRequest request, HttpServletResponse response)  throws ServletException, IOException {

     boolean isMultipart = ServletFileUpload.isMultipartContent(request);
     GWT.log("is multipart? " + Boolean.toString(isMultipart), null);

     ServletFileUpload upload = new ServletFileUpload();

     try{
            FileItemIterator iter = upload.getItemIterator(request);

            while (iter.hasNext()) {
                    FileItemStream item = iter.next();
                    String name = item.getFieldName();
                    InputStream stream = item.openStream() ;

                    /**
                    * Save th uploaded file
                    */

            }
     }
    catch(Exception e){
            e.printStackTrace();
    }
 }
How can I save the uploaded file?
解决方案
I think this can help you. 
if (!item.isFormField()) {
    String fieldName = item.getFieldName();
    String fileName = item.getName();
    String contentType = item.getContentType();
    boolean isInMemory = item.isInMemory();
    long sizeInBytes = item.getSize();

  File saveTo = new File("/file_uploads/" + fileName);
  try {
    item.write(saveTo);
    ...
  }
  catch (Exception e){
    ...
  }
Keep in mind that uploaded file may already be automatically saved by org.apache.commons.fileupload

You can set size threshold for file to be saved on disk or loaded in memory using 
// Create a factory for disk-based file items
DiskFileItemFactory factory = new DiskFileItemFactory();

// Set factory constraints
factory.setSizeThreshold(yourMaxMemorySize);
factory.setRepository(yourTempDirectory);

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

// Set overall request size constraint
upload.setSizeMax(yourMaxRequestSize);

// Parse the request
List /* FileItem */ items = upload.parseRequest(request);
Everything you need to know about org.apache.commons.fileupload is here: Using FileUpload

                        
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