Parameter value is always null or set to default value on TIBCO JasperReports® Server. Works fine in TIBCO Jaspersoft® Studio

Issue description

I recently ran into this scenario: user's report has several parameters used in query and in other parts of the report. The report is running fine in TIBCO Jaspersoft® Studio, but once published to TIBCO JasperReports^® Server returns no data. Once we checked the generated query it became obvious that parameter values were all NULLs, even though user entered values when prompted.

Cause

All the parameters in the report were name using the following pattern:

@MY_PARAMETER_NAME

The problem is that when publishing a report to JasperReports^® Server, Input control name and label is created for each parameter based on its name. However some special characters like the 'at' symbol @ are forbidden in Input Control IDs. So Jaspersoft® Studio would silently replace the @ with an underscore _, like this:

_MY_PARAMETER_NAME

The Input Control labels would remain with special characters though, e.g.:

@MY_PARAMETER_NAME

Which makes it less obvious that there is a difference between parameter name and Input Control ID.

Solution

A simple solution for this is to avoid using special characters in parameter names