Download Excel file from Seam component...

[yshashidhar]

Hi

I have a requirement where in I need to give functionality to user for downloading excel file from server.
I was walking through various posts over here, but my issue is not resolved... Please see below what I have done..

xhtml code:
<s:link id="slinkexportxls" value="Download" action="#{qualityIP.exportExcel}">
</s:link>

And here is my exportExcel method:
createExcel();
               
                 HttpServletResponse httpResponse =
                         (HttpServletResponse)FacesContext.getCurrentInstance().getExternalContext().getResponse();
                 System.out.println("injected extCtx, httpoutput buffersize= - " + httpResponse.getBufferSize());
                
                 File fFile = new File("D:\\Shashi\\ExportInspectionPlanToExcel.xls");
                 String stFileName = "ExportInspectionPlanToExcel.xls";
                
                 httpResponse.setHeader ("Content-Disposition","attachment;filename=\""+stFileName+"\"");
                
                 //the content type set as excel
                 httpResponse.setContentType("application/vnd.ms-excel");
                
                 System.out.println("ExportInspectionPlanToExcel: Set all return properties...");
                 
                 //Open an input stream to the file and post the file contents thru the
                 //servlet output stream to the client m/c
                 InputStream isStream = null;
                 ServletOutputStream sosStream = null;
                 try {
                         //response.flushBuffer();
                         isStream = new FileInputStream(fFile);
                         sosStream = httpResponse.getOutputStream();
                         int ibit = 256;
                         while ((ibit) >= 0){
                                 ibit = isStream.read();
                                 sosStream.write(ibit);
                         }
                         System.out.println("ExportInspectionPlanToExcel: Done, closing all open streams...");
                         sosStream.flush();
                         System.out.println("Flushed, closing sos...");
                         sosStream.close();
                
                 } catch (IOException exp){
                         System.out.println("exception -" +exp.getStackTrace());
                 }
                 FacesContext.getCurrentInstance().responseComplete();

And that's it I have done... when I ran the above application... I don't see exportExcel method getting called after clicking Download Seam link

Can any help please me where did I made mistake?

[yshashidhar]

Sorry improper format in above post...
Here is my exportExcel method -

               createExcel();
                
                 HttpServletResponse httpResponse = 
                         (HttpServletResponse)FacesContext.getCurrentInstance().getExternalContext().getResponse();
                 System.out.println("injected extCtx, httpoutput buffersize= - " + httpResponse.getBufferSize());
                 
                 File fFile = new File("D:\\Shashi\\ExportInspectionPlanToExcel.xls"); 
                 String stFileName = "ExportInspectionPlanToExcel.xls";
                 
                 httpResponse.setHeader ("Content-Disposition","attachment;filename=\""+stFileName+"\"");
                 
                 //the content type set as excel 
                 httpResponse.setContentType("application/vnd.ms-excel");
                 
                 System.out.println("ExportInspectionPlanToExcel: Set all return properties...");
                  
                 //Open an input stream to the file and post the file contents thru the 
                 //servlet output stream to the client m/c 
                 InputStream isStream = null; 
                 ServletOutputStream sosStream = null; 
                 try {
                         //response.flushBuffer(); 
                         isStream = new FileInputStream(fFile);
                         sosStream = httpResponse.getOutputStream(); 
                         int ibit = 256; 
                         while ((ibit) >= 0){ 
                                 ibit = isStream.read(); 
                                 sosStream.write(ibit); 
                         }
                         System.out.println("ExportInspectionPlanToExcel: Done, closing all open streams...");
                         sosStream.flush();
                         System.out.println("Flushed, closing sos...");
                         sosStream.close();
                 
                 } catch (IOException exp){ 
                         System.out.println("exception -" +exp.getStackTrace()); 
                 }
FacesContext.getCurrentInstance().responseComplete();

And here is my xhtml piece of code

<s:link id="slinkexportxls" value="Download" action="#{qualityIP.exportExcel}">
</s:link>

[yshashidhar]

Any one reply me please.
It's bit urgent to me

[pbrewer_uk]

Your code looks fine to me - I can't spot any obvious reason for it failing. I suppose a JSF validator doesn't prevent submission? You can check this by adding a h:messages component (and making sure it is reRendered or the page refreshed).

If it helps, this is code that I've used before that works:

DownloadBean.java

import org.jboss.seam.document.ByteArrayDocumentData;

...

  public void download() {
    download(generateData(), "attachment") ;
  }

  private ByteArrayDocumentData generateData() {
    return new ByteArrayDocumentData(...) ;
  }

  private boolean download(ByteArrayDocumentData data, String disposition) {

    if (data == null) {
      return false;
    }
    
    try {
      FacesContext facesContext = FacesContext.getCurrentInstance() ;
      HttpServletResponse response = (HttpServletResponse) facesContext.getExternalContext().getResponse() ;

      String downloadFilename = data.getFileName() ;   
      response.setContentType( data.getDocumentType().getMimeType() );
      if (downloadFilename != null ) {
        response.setHeader("Content-disposition", disposition + "; filename=\"" + downloadFilename + "\"");
      }
      OutputStream out = response.getOutputStream();
      data.writeDataToStream(out) ;
      response.flushBuffer() ;
      facesContext.responseComplete();
      return true ;
    } catch(Exception ex) {
      LOG.error("Error downloading report #0", ex, getReportViewId()) ;
      return false ;
    }    
  }

download.xhtml

<h:commandButton actionListener="#{downloadBean.download}" value="#{messages.downloadExport}" />

[yshashidhar]

Okay... This time I changed my design slightly... Unfortunately I didn't the excel exported, but there are no errors in console...

My xhtml code:

<h:form id="qualityIPlanForm" style="width: 954px; height: 409px" enctype="multipart/form-data">
...
<a4j:commandButton value='Download' action="#{qualityIP.exportExcel}"/>

And here is my exportExcel (Modified version)

          createExcel();
          
           HttpServletResponse httpResponse = 
                (HttpServletResponse)facesContext.getExternalContext().getResponse();
           
           File fFile = new File("D:\\Shashi\\ExportInspectionPlanToExcel.xls"); 
           String stFileName = "ExportInspectionPlanToExcel.xls";
           
           httpResponse.setHeader ("Content-Disposition","attachment;filename=\""+stFileName+"\"");
           
           //the content type set as excel 
           httpResponse.setContentType("application/vnd.ms-excel");
           
           System.out.println("ExportInspectionPlanToExcel: Set all return properties...");
            
           //Open an input stream to the file and post the file contents thru the 
           //servlet output stream to the client m/c 
           InputStream isStream = null; 
           ServletOutputStream sosStream = null; 
           try {
                //response.flushBuffer(); 
                isStream = new FileInputStream(fFile);
                sosStream = httpResponse.getOutputStream(); 
                int ibit = 256; 
                while ((ibit) >= 0){ 
                     ibit = isStream.read(); 
                     sosStream.write(ibit); 
                }
                System.out.println("ExportInspectionPlanToExcel: response Complete, redirected...");
                httpResponse.flushBuffer();
                facesContext.responseComplete();
                return "Success";
           } catch (IOException exp){ 
                System.out.println("exception -" +exp.getStackTrace());
                return "Failed";
           }

My exportExcel method returns String, indicating Success/Fail of method execution... I hope this m8 not create any prob...

Unfortunately in server console I see all system out messages... but on browser I don't see the excel downloading... :-(

Any help please?

[pbrewer_uk]

You could try changing your xhtml to the following, just to see if it works:

<h:commandButton value='Download' actionListener="#{qualityIP.exportExcel}"/>

I seem to remember it is a bit funny getting your setup to work properly.

Also, you may want to investigate the document store facility and <s:resource> tag that I think may be of use to you (I know very little about this though).

[yshashidhar]

Tried with h:commandButton, but the same situation... No error on console and nothing is happening at UI.
Instead, I can say everything is executing fine inside method I have written.... but in IE there is no download option coming


"I tried with <s:resource> it seems the tag has no definition in xmlns defined at here "

`<s:resource xmlns="http://www.w3.org/1999/xhtml"

    xmlns:s="http://jboss.com/products/seam/taglib"

    data="#{resources.data}"

    contentType="#{resources.contentType}"

    fileName="#{resources.fileName}" />

`

Any help is really appreciated...""

[pbrewer_uk]

What version of Seam are you using? s:resource wasn't available until 2.1.2. Also don't forget to configure the web.xml as the documentation suggests.

As a side-note, your first post said you used

<s:link id="slinkexportxls" value="Download" action="#{qualityIP.exportExcel}">
</s:link>

So you should not need to add the xml namespace again - it should already be defined (i.e. remove xmlns:s and xmlns attributes from s:resource if it already appears further up the page), I don't think that would cause any problems though, its just more tidy.

[yshashidhar]

I am using Seam 2.0... so I think i can use s:resource functionality.

                                   <s:link id="slinkexportxls" value="Download" action="#{qualityIP.exportExcel}">
                                   </s:link>
                                   <rich:spacer width="2px"/>
                                   <a4j:commandButton action="#{qualityIP.exportExcel}" value="" 
                                        image="/img/images/imgIconExcel_16x16.gif"
                                        style="vertical-align:middle; width: 16px;"/>
                                   <rich:spacer width="2px"/>

1 First I tried with s:link and see the function itself calling which is defined inside method...

Here is the code for the same

                                   <s:link id="slinkexportxls" value="Download" action="#{qualityIP.exportExcel}">
                                   </s:link>

in this case exportExcel itself is not calling...

2 In second shot, I am making use of command button as shown above. This time it executes complete exportExcel method shown below

           HttpServletResponse httpResponse = 
                (HttpServletResponse)facesContext.getExternalContext().getResponse();
           
           File fFile = new File("D:\\Shashi\\ExportInspectionPlanToExcel.xls"); 
           String stFileName = "ExportInspectionPlanToExcel.xls";
           
           httpResponse.setHeader ("Content-Disposition","attachment;filename=\""+stFileName+"\"");
           
           //the content type set as excel 
           httpResponse.setContentType("application/vnd.ms-excel");
           
           System.out.println("ExportInspectionPlanToExcel: Set all return properties...");
            
           //Open an input stream to the file and post the file contents thru the 
           //servlet output stream to the client m/c 
           InputStream isStream = null; 
           ServletOutputStream sosStream = null; 
           try {
                //response.flushBuffer(); 
                isStream = new FileInputStream(fFile);
                sosStream = httpResponse.getOutputStream(); 
                int ibit = 256; 
                while ((ibit) >= 0){ 
                     ibit = isStream.read(); 
                     sosStream.write(ibit); 
                }
                isStream.close();
                sosStream.flush();
                System.out.println("ExportInspectionPlanToExcel: response Complete, redirected...");
                
                httpResponse.flushBuffer();
                facesContext.responseComplete();
                facesContext.renderResponse();
                return "Success";
           } catch (IOException exp){ 
                System.out.println("exception -" +exp.getStackTrace());
                return "Failed";
           }

Even I see all system out messages. But in browser I don't see the file getting downloaded...

[yshashidhar]

Sorry typo..
my say in previous post I think i can use s:resource functionality
should have been I think i can't use s:resource functionality

btw, should I need to do anything on server to respond for downloads?