A XSQLRequest Mystery Solved: Please Read

Question

On various occasions, folks have complained that, when working with the XSQLRequest class, that their parameters are not properly handled. It always seems to happen when they are creating the XSQLRequest object by passing it a URL which is based on an http://[] protocol scheme.
Today I believe I finally found the explanation for this, so let me explain.
Say you have an XSQL Page like this:<xsql:query connection="research" xmlns:xsql="urn:oracle-xsql">
select pkTelephone.registerDamage
( to_number({@txtTelephone}),
to_number({@txtDamageType}),
'{@txtComments}'
) as RESULT
from dual
</xsql:query>and a sample program that's trying to use XSQLRequest like this:import oracle.xml.xsql.XSQLRequest;
import java.util.Hashtable;
import java.io.PrintWriter;
import java.net.URL;
public class XSQLRequestSample
public static void main( String[] args) throws Exception
// Construct the URL of the XSQL Page
URL pageUrl = new URL("http://fchaves/iopenflex/xapi/dano.registrar.xsql");
// Construct a new XSQL Page request
XSQLRequest req = new XSQLRequest(pageUrl);
Hashtable params = new Hashtable(4);
params.put("txtTelephone","1");
params.put("txtDamageType","1");
params.put("txtComments","1");
req.process(params,new PrintWriter(System.out),new PrintWriter(System.err));
}When the XSQLRequest class retrieves the XSQL page template to process by requesting the URL that is specified, [b]http://fchaves/iopenflex/xapi/dano.registrar.xsql, it requests the "dano.registrar.xsql" page from the fchaves web server (listening on the default port 80).
Since (as is likely the case with many of the customers who have reported the problem here) the fchaves web server is configured to process requests for pages that end in *.xsql using the XSQL Servlet, before the requesting program -- the XSQLRequestSample in this case -- receives the result, the page is processed on the server by the XSQL Servlet before getting returned to the XSQLRequest class.
Since the request for the b]http://fchaves/iopenflex/xapi/dano.registrar.xsql page does not specify any parameters on the URL, then when the page is processed on the server, all three of the parameters it is expecting (txtTelephone,txtDamageType,txtComments) are blank, so the server-side XSQL Servlet engine processes the page and ends up producing and returning the resulting page to the requesting XSQLRequest class:
<xsql-error action="xsql:query">
<statement>select pkTelephone.registerDamage
( to_number(),
to_number(),
) as RESULT
from dual</statement>
<message>ORA-00938: not enough arguments for function
</message>
</xsql-error>The XSQLRequest class then tries to process this returned XML document as an XSQL page template and, not finding any XSQL action elements in the <xsql:*> namespace, simply passes the document through as is.
So, the result is that the person who runs the XSQLRequestSample program gets an output that looks like the one above and cannot understand why his parameters that are being passed to the XSQLRequest class aren't getting used correctly. The answer is, they are getting passed correctly but by the time the XSQLRequest class sees the page for processing, the page is not the same page you think you're getting!
The ways to avoid this problem are:
[list=1]
[*]Use a file:// URL to reference the XSQL page template.
[*]Change the extension on the file served by your webserver to anything besides *.xsql. For example, renaming dano.registrar.xsql to dano.registrar.xyz would work)
[list]
Hopefully this helps explains a lot of mysteries that people have run into.

Answer 1

Thank you, that does explain a lot.
It does present the problem, that it is not possible to use the same XSQL file from a <jsp:include> statement and from the API ...
Cheers,
Morten