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RE: Requests to a servlet

From: <mnautiyal@hss.hns.com>
Date: Sat, 1 Dec 2001 12:10:07 +0530
To: www-lib@w3.org
Message-ID: <65256B15.0024FDBC.00@sandesh.hss.hns.com>


RE: Requests to a servlet

  Hello Dave,

   My requirement is the similar to that of yours. I've to get the XML response
back from the
   servelet I post data.  I started with the post.c (sample program). It works
but with user interaction.
    i.e it asks file name for saving the response. However I want the response
as in memory (or as a chunk).
    I tried the solution provided by Andreas. However, the problem  remains the
same. The prompt comes
    for saving the response in a file. The response is correct, that I need. I
went through the library and saw
    a function HTSaveLocally()  (in HTFSave.c) is invoked when repsonse comes.
This function is invoked
   when the MIME parser  understands that the content-type is application/octet
stream or unknown encoding
   is seen. Please respond and provide your comments to solve this problem.
   Following is the customised post.c that I'm using.

PRIVATE int terminate_handler (HTRequest * request, HTResponse * response,
                               void * param, int status)
{
    if (status == HT_LOADED && result && HTChunk_data(result)) {
        HTPrint("---Printing response---->%s", HTChunk_data(result));
        HTChunk_delete(result);
    }

    /* We are done with this request  */
    HTRequest_delete(request);

    /* Terminate libwww */
    HTProfile_delete();

    exit(0);
}


PUBLIC HTChunk * HTPostAnchorToChunk (HTParentAnchor *  source,
                         HTAnchor *             destination,
                         HTRequest *            request)
{
  if (source && destination && request) {
    HTChunk * chunk = NULL;
    HTStream * target = HTStreamToChunk(request, &chunk, 0);
    HTRequest_setOutputStream(request, target);
    if (HTPostAnchor(source, destination, request) != NULL)
      return chunk;
    else {
      HTChunk_delete(chunk);
      return NULL;
    }
  }
  return NULL;
}
int main (int argc, char ** argv)
{
    HTRequest * request = NULL;
    HTParentAnchor * src = NULL;
    HTAnchor * dst = NULL;
    HTAnchor * anchor = NULL;
    char * dst_str = NULL;
    char * data = NULL;
    BOOL status = NO;

    /* Initiate libwww :- Create a new premptive client  */
    HTProfile_newNoCacheClient("libwww-POST", "1.0");

    /* Need our own trace and print functions */
    HTPrint_setCallback(printer);
    HTTrace_setCallback(tracer);

    /* Add our own filter to update the history list */
    HTNet_addAfter(terminate_handler, NULL, NULL, HT_ALL, HT_FILTER_LAST);

    /* Handle command line args */
    if (argc >= 3) {
        dst_str = argv[1];
        xml_data = argv[2];
} else {
        HTPrint("Type the URI of the destination you want to POST to and the
contents that you w
ant to post.\n");
        HTPrint("\t%s <destination> <data>\n", argv[0]);
        HTPrint("For example, %s http://myserver/destination.html \"This is some
 testdata\"\n",
               argv[0]);
                return -1;
    }

    if (xml_data && *xml_data && dst_str && *dst_str) {

        /* Make source relative to where we are */
        char * cwd = HTGetCurrentDirectoryURL();
     request = HTRequest_new();
    HTRequest_setOutputFormat(request, HTAtom_for("text/xml"));

    anchor = HTAnchor_findAddress(dst_str);

    /* dst_str is the Destination Address: http://www.xxx */
    /* xml_data is the XML Data you would like to send */

    src = HTTmpAnchor(NULL);
    HTAnchor_setDocument(src, xml_data);
    HTAnchor_setFormat(src, HTAtom_for("text/xml"));
    HTAnchor_setCharset(src, HTAtom_for("UTF-8"));
    HTAnchor_setLength(src, strlen(xml_data));

    {
        HTChunk * chunk;
        char *string;
        chunk = HTPostAnchorToChunk(src, anchor, request);

           if (!chunk)
             {
printf ("NULL Response!!\n");
             }
         /* If chunk != NULL then we have the data */
         if (chunk) {
                 HTEventList_loop(request);
/* After event loop the following statements are not executed...!!!*/
                 string = HTChunk_toCString(chunk);
                 HTPrint("%s", string ? string : "no text\n");
                 HT_FREE(string);
        }

     }
}

return 0;
}


Thanks,
Manoj Nautiyal




  From: Mikesell, Dave (dmikesell@cas.org)
  Date: Tue, Sep 25 2001

  *Next message: Jun Wang: "RE: CVS on Win98"

     * Previous message: SMIGIELSKI ANDREAS: "Re: Requests to a servlet"
     * Maybe in reply to: Mikesell, Dave: "Requests to a servlet"
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    ------------------------------------------------------------------------

  Message-ID: <117BB2BA200DD311850D0004AC66D3DE0A3B9D16@pop-server.cas.org>
  From: "Mikesell, Dave" <dmikesell@cas.org>
  To: "'www-lib@w3.org'" <www-lib@w3.org>
  Date: Tue, 25 Sep 2001 11:10:21 -0400
  Subject: RE: Requests to a servlet

  Thanks to all who responded.  The "missing link" in my original solution was
the call to HTRequest_setOutputStream() to catch the
  response from a post.

  --
  Dave Mikesell
  Chemical Abstracts Service
  614.447.3600 x2993

  > -----Original Message-----
  > From: Mikesell, Dave
  > Sent: Monday, September 24, 2001 10:26 AM
  > To: 'www-lib@w3.org'
  > Subject: Requests to a servlet
  >
  >
  > Greetings.  We have a client library written in C that
  > provides access to our J2EE environment.  Without going into
  > to much detail, each library function causes an XML message
  > to be sent over a socket to the server, which in turn parses
  > the message, invokes the proper J2EE service, and then sends
  > an XML response back to the client.  We would like to replace
  > our socket/home-grown protocol with HTTP using libwww.  This
  > would involve sending raw XML to a servlet and waiting for
  > the servlet to send back an XML response.
  >
  > Is this possible using libwww?  From what I can tell, the
  > closest thing to what we need is HTPostFormAnchorToChunk(),
  > but we don't have a "form" per se...just XML.  Any insight
  > would be greatly appreciated.  Thank you.
  >
  > Dave
  >

    ------------------------------------------------------------------------

     * Next message: Jun Wang: "RE: CVS on Win98"
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     * Maybe in reply to: Mikesell, Dave: "Requests to a servlet"
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Received on Saturday, 1 December 2001 01:44:03 GMT

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