gwtupload：设置动态文件上传大小

Question

I'm working around file upload in GWT. My test application working fine. I want to set different file upload limit for different upload widget created by gwtupload . ( Project Home )

SingleUploader sUploader = new SingleUploader();

I set upload limit in web.xml using below code. Is there any option to set different file size at run time?

<context-param>
    <!-- max size of the upload request -->
    <param-name>maxSize</param-name>
    <param-value>3145728</param-value>
  </context-param>

Answer 1

In the gwtupload UploadServlet.java class there's this method you can override which gets called before the request is passed on to org.apache.commons.fileupload.servlet.ServletFileUpload:

public void checkRequest(HttpServletRequest request) {
    logger.debug("UPLOAD-SERVLET (" + request.getSession().getId() + ") procesing a request with size: " + getContentLength(request) + " bytes.");
    if (getContentLength(request) > maxSize) {
      throw new UploadSizeLimitException(maxSize, getContentLength(request));
    }
}

If you need to modify the max allowed size client side via SingleUploader you could do this by passing the maxsize in a hidden form field and checking it in an overridden checkRequest method. The size configured in the web.xml would then be checked a second time but the apache library and be the absolute max size. ie you could restrict to a number /lower/ than that but not higher.

I eventually gave up on gwtupload because of things like this and rolled my own, it was fairly easy using the apache fileupload library and much more flexible.

Answer 2

just override the below. it worked for me, maxSize is a protected variable in superclass

@Override
public void init() throws ServletException {
    maxSize = 157286400;
    super.init();
}

@Override
public void checkRequest(HttpServletRequest request) {
    maxSize = 157286400;
    super.checkRequest(request);
}