Substitution strings not working in URLs for web service references (bug?)

Question

We have an environment where the url for our BPEL server is read from a variable. I've created an application item and a corresponding application-level computation. I'm using the ampersand-followed-by-dot (&BPEL_SERVER.) syntax as well as the hashmark syntax (#BPEL_SERVER#) and am unable to get this working.
Is there a way for me to debug web service reference calls other than whether a call was successful? Is this a bug?
edit:
Here is the error message I get when I try to use a substitution:
ORA-20001: The webservice was unreachable because either the URL you supplied was invalid, your environment requires a valid proxy server address for HTTP requests, or a wallet needs to be configured for HTTPS requests.

Answer 1

No problem - let me try to lay this out a little differently, perhaps I'm just missing something.
problem:
* we have separate development, test, and production servers for our database and bpel servers.
* The hostnames for these servers are stored in a table of key/value pairs
* This means that (by policy) the hostnames in URLs calling BPEL web services should be the value corresponding to BPEL_SERVER so that the appropriate bpel server is used to call the web service
attempted solution:
1) I created an application item named BPEL_SERVER
2) I have a before-header computation that sets BPEL_SERVER to 'http://bpeldev' using a static value assignment
3) I have a web service reference whose URL is either &BPEL_SERVER./orabpel/default/callNotification/1.0 or #BPEL_SERVER#/orabpel/default/callNotification/1.0
4) The web service reference is called in an after-submit process.
5) An invalid URL exception is thrown for this process.when submitting on the page containing this process
observations:
* for (3) - I can set the URL to http://bpeldev/orabpel/default/callNotification/1.0 and everything occurs successfully
* for (3) - If I use http://bpeldev/&BPEL_SERVER. then when I execute (4), I see a request for the exact string http://bpeldev/&BPEL_SERVER. in bpeldev's access logs
* for (3) - If I use http://bpeldev/#BPEL_SERVER# then when I execute (4), I see a request for the exact string http://bpeldev/#BPEL_SERVER# in bpeldev's access logs
* for (2) I've also used a function call RETURN get_const_value('BPEL_SERVER'); - same results for (5)
* the item value has ben verified before (5)
* for (1) and (2) I've tried defining substitution strings in the application definition instead - same results for (5)