Upload/ Download with dynamic contents

Question

Hi Friends,
I have to download a table content to an excel sheet that is dynamically generated on the basis of users' selection. I gone through examples 23 & 39 given in samples section for web dynpro but that works when I know the exact file to be downloaded from WAS but in my case, I have to create a file (as it seems to me) having the dynamically generated content & then I can download it to the client system. Here comes the problem, jxl package is not getting recognised by Web Dynpro (atleast not with the version I am using) and I am not getting any Web Dynpro API that can work in my case.
Please help me out as this problem is obstructing my way in creating a critical development component.
Thanks & Regards,
Aditya P. Srivastava

Answer 1

Hi Mahesh,
I am using SAP Netweaver 2.0.16 and I tried jxl.write.WritableWorkbook to do the desirable but Web Dynpro is not recognising the above said package. So, I
have to abandon the approach.
Now I am trying the one having the following steps:
(1) In the eventhandler for the link to "Download to Excel" (LinkTOAction UI),
    I am trying to implement the following code:
/This method, after setting the file name & MIME type for the context attribute FileResource (that corresponds to link "Download to Excel"), fetches the path for the node that holds the data I have to download, and then sets that data to the above said path for the context attribute FileResource after converting it into byte[] (as FileResource is of type binary)/
public void onActionDownloadExcel(com.sap.tc.webdynpro.progmodel.api.IWDCustomEvent wdEvent )
    //@@begin onActionDownloadExcel(ServerEvent)
     IWDAttributeInfo attInfo = wdContext.getNodeInfo().getAttribute(IPrivateZuw_ReposView.IContextElement.CTX__VA__FILE_RESOURCE);
//     attInfo.getModifiableSimpleType();
     IWDModifiableBinaryType binary = (IWDModifiableBinaryType)attInfo.getModifiableSimpleType();
     binary.setFileName(fileName);
     binary.setMimeType(WDWebResourceType.XLS);
     IPrivateZuw_ReposView.ICtx_vn_showallNode showData = wdContext.nodeCtx_vn_showall();
     IPrivateZuw_ReposView.ICtx_vn_showallElement showEle = null;
     try
          String resourcePath = WDURLGenerator.getResourcePath(wdContext.nodeCtx_vn_showall().toString());
          wdComponentAPI.getMessageManager().reportSuccess(resourcePath);
          ByteArrayOutputStream out = new ByteArrayOutputStream();
          out = this.getByteArrayFroResourcePath(resourcePath);
                                if(out != null)
          wdContext.currentContextElement().setCtx_va_FileResource(out.toByteArray());
                                else
                                   wdComponentAPI.getMessageManager().reportWarning("ByteArrayOutputStream returned as NULL");
     catch(Exception e)
          wdComponentAPI.getMessageManager().reportWarning("Exception");
    //@@end
(2) And for the function getByteArrayFroResourcePath(String), I've written:
/*This returns ByteArrayOutputStream for the given resourcePath (It is, in my case, for the context node that holds the data I have to download) */
public java.io.ByteArrayOutputStream getByteArrayFroResourcePath( java.lang.String resourcePath )
    //@@begin getByteArrayFroResourcePath()
     try
            FileInputStream in = new FileInputStream(new File(resourcePath));
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int length;
            byte[] part = new byte[10*1024];
            while((length = in.read(part)) != -1 )
                 out.write(part, 0 , length);
            in.close();
            return out;
            catch(FileNotFoundException e)
                 wdComponentAPI.getMessageManager().reportException(e.getLocalizedMessage(),true);
            catch(IOException e)
                 wdComponentAPI.getMessageManager().reportException(e.getLocalizedMessage(),true);
            return null;
    //@@end
But this approach, though seems to me quite right, has problem. As the context node that holds data I need to download in Excel is not a Deployable object, so the system doesn't returns me the resource path; instead it is giving me
".\temp\webdynpro\web\Context_Node(system cannot find the file specified)".
ByteArrayOutputStream returned as NULL.
See into the issue and help me in getting the right solution.
Thanks & Regards,
Aditya P. Srivastava