[Multigraph-users] Best practice for handling errors within a web service used by the Multigraph Flex Component?

[James A. <mon...@gm...>]

I have a Flex application that uses the Multigraph Flex Component.
When I construct this component in my application code I specify a URL
to a  web service that will respond with MUGL for the multigraph.
This web service is a Java Servlet.  If there is an error processing
the MUGL request then I want to display a meaningful message to the
user (in the Flex client application), as well as logging the error
and sending a message to alert the developer (me) of the issue.

What is the best way for the web service servlet to respond to an
error such as an invalid request parameter?  Are there certain HTTP
response codes that this Multigraph Flex Component is aware of and
handles gracefully?

For example:

My application creates a Multigraph component and sets the web service
URL (i.e. the Multigraph component's muglfile attribute/property) to
something which contains a bad request parameter:

multiGraph.muglfile =
"http://jadams.ncdc.noaa.gov/graphapp/mugl_for_station?station_code=INVALID_STATION_CODE";

What is the best way to handle the error in my web service code?  When
I catch the error I can throw an exception from the servlet, and this
will create an HTTP response with a non-200 HTTP response code -- can
the Multigraph component handle this, and if so how do I capture the
error message?

Thanks for any suggestions.

--James