Question

你好我试图使用java文件上传文件..但我不明白..我得到文件大小= 0我在这里提供我的java代码。告诉我为什么我不能上传特定的文件夹。我想将我的文件存储在特定文件夹中。我想获取文件大小，文件名但我得到空值我错了请告诉我。

public void updateTesti(ActionRequest actionRequest,ActionResponse actionResponse) throws IOException, PortletException
{
    //image upload logic
    String folder_for_upload =(getPortletContext().getRealPath("/"));
    //String folder=actionRequest.getParameter("uploadfolder");
    realPath=getPortletContext().getRealPath("/");  

    logger.info("RealPath is" + realPath);
    logger.info("Folder is :" + folder_for_upload);
    try
    {
        logger.info("Admin is try to upload");

        UploadPortletRequest uploadRequest = PortalUtil.getUploadPortletRequest(actionRequest);

        if (uploadRequest.getSize("fileName") == 0) {
            SessionErrors.add(actionRequest, "error");
        }
        String sourceFileName = uploadRequest.getFileName("fileName");
        File uploadedFile = uploadRequest.getFile("fileName");
        System.out.println("Size of uploaded file: " + uploadRequest.getSize("fileName"));

        logger.info("Uploded file name is: " + uploadRequest.getFileName("fileName"));                  
        String destiFolder=("/home/ubuntu/liferay/liferay-portal-6.1.1-ce-ga2/tomcat-7.0.27/webapps/imageUpload-portlet/image");
        String newsourcefilename = (uploadRequest.getFileName("fileName"));
        File  newFile = new File(destiFolder +"/"+ newsourcefilename);

        logger.info("New file name: " + newFile.getName());
        logger.info("New file path: " + newFile.getPath());

        InputStream in = new BufferedInputStream(uploadRequest.getFileAsStream("fileName"));

        FileInputStream fis = new FileInputStream(uploadedFile);
        FileOutputStream fos = new FileOutputStream(newFile);
        byte[] bytes_ = FileUtil.getBytes(in);
        int i = fis.read(bytes_);
        while (i != -1) {
            fos.write(bytes_, 0, i);
            i = fis.read(bytes_);
        }
        fis.close();
        fos.close();
        Float size = (float) newFile.length();

        System.out.println("file size bytes:" + size);
        System.out.println("file size Mb:" + size / 1048576);

        logger.info("File created: " + newFile.getName());
        SessionMessages.add(actionRequest, "success");

    }
    catch (FileNotFoundException e)
    {
        System.out.println("File Not Found.");
        e.printStackTrace();
        SessionMessages.add(actionRequest, "error");
    }
    catch (NullPointerException e)
    {
        System.out.println("File Not Found");
        e.printStackTrace();
        SessionMessages.add(actionRequest, "error");
    }
    catch (IOException e1)
    {
        System.out.println("Error Reading The File.");
        SessionMessages.add(actionRequest, "error");
        e1.printStackTrace();
    }
}

Answer 1

你需要这样做才能上传小文件＆lt; 1kb的

File f2 = uploadRequest.getFile("fileupload", true);

它们仅存储在内存中。我在我的catch语句中有它，因为我得到一个空指针 - 或者包含我的原始文件（f1.length）== 0

Answer 2

我已经执行了你的代码。它正在按照期望工作。你的jsp页面可能有问题。我不确定但你的名字属性可能与你在{{1 （假设您正在使用portlet）.Parameter区分大小写，因此请再次检查。

您可以在下面的链接中找到更多信息。在文件上传方面有很好的解释。

http://www.codeyouneed.com/liferay-portlet-file-upload-tutorial/

Answer 3

我浏览了一个文件上传代码，当我在我的本地系统中实现我得到的是，portlet正在保存我在tomcat/webbapp/abc_portlet_project位置上传的文件，我不明白的是从哪里找到portlet < / p>

String folder = getInitParameter（＆＃34; uploadFolder＆＃34;）;
               String realPath = getPortletContext().getRealPath("/");

               System.out.println("RealPath" + realPath +"\\" + folder); try {
UploadPortletRequest uploadRequest =   PortalUtil.getUploadPortletRequest（的ActionRequest）;   System.out.println（＆＃34;大小：＆＃34; + uploadRequest.getSize（＆＃34; fileName＆＃34;））;

if（uploadRequest.getSize（＆＃34; fileName＆＃34;）== 0）   {SessionErrors.add（actionRequest，＆＃34; error＆＃34;）;}

String sourceFileName = uploadRequest.getFileName（＆＃34; fileName＆＃34;）;文件   file = uploadRequest.getFile（＆＃34; fileName＆＃34;）;

System.out.println（＆＃34; Nome文件：＆＃34; +   uploadRequest.getFileName（＆＃34;文件名＆＃34））;文件newFolder = null;   newFolder =新文件（realPath +＆＃34; \＆＃34; +文件夹）;   if（！newFolder.exists（））{newFolder.mkdir（）; }                File newfile = null;                  newfile = new File（newFolder.getAbsoluteFile（）+＆＃34; \＆＃34; + sourceFileName）;                  System.out.println（＆＃34;新文件名：＆＃34; + newfile.getName（））;                  System.out.println（＆＃34;新文件路径：＆＃34; + newfile.getPath（））;

InputStream in = new   的BufferedInputStream（uploadRequest.getFileAsStream（＆＃34;文件名＆＃34））;   FileInputStream fis = new FileInputStream（file）; FileOutputStream fos   = new FileOutputStream（newfile）;

如何使用java上传文件？

3 个答案: