Loading a file from a parameter in Jasper - jasper-reports

Question

I'm new to writing jasper reports (and SQL in general). We are trying to load an RTF or HTML file as a disclosure at the end of a report. The way we are doing this is by selecting the name of the file ("Disclosure") in part of the SQL:
SELECT
....
'Disclosure' as Disclosure
FROM
...
And then, obviously, there is a field for this:
<field name="Disclosure" class="java.lang.String"/>
At the end, in the summary section of the report, we use the loadfile utility:
<textFieldExpression class="java.lang.String"><![CDATA[JasperFileRuntimeUtility.loadFile($F{Disclosure}, $P{REPORT_PARAMETERS_MAP})]]></textFieldExpression>
If the report returns data, this works beautifully. But if the result of the original query does not return any records, then the disclosure is not included in the report (since the result of the query is nothing, obviously).
I thought we could easily work around this by providing the "Disclosure" as a Parameter, but when I change that to $P instead of $F. I get an error about invalid io file type.
I also tried creating a Variable and setting that $V to the value of the $P we are passing in, but no luck there either.
Is there a load file type of utility that will load a parameter like we are doing with the field? Any other suggestions?
Appreciate the help!!!

Answer 1

I have understood you question better now so I edit the answer, you are calling
JasperFileRuntimeUtility.loadFile($F{Disclosure}, $P{REPORT_PARAMETERS_MAP})
you have no clue what function is this but you know that if you pass the String "Disclosure" it works.
The class JasperFileRuntimeUtility is within your library (its not an official jasper report function), try to search your project or your libraries.
It has a static method public static String loadFile(String value, Map<?,?> map)
Calling the metod with where $F{Disclosure} = "Disclosure"
JasperFileRuntimeUtility.loadFile($F{Disclosure}, $P{REPORT_PARAMETERS_MAP})
or
JasperFileRuntimeUtility.loadFile("Disclosure", $P{REPORT_PARAMETERS_MAP})
will not make any different the result will be the same (since the method have no other idea then with what parameters you call it).
Normally also calling with a $P{Disclosure} = "Disclosure"
JasperFileRuntimeUtility.loadFile($P{Disclosure}, $P{REPORT_PARAMETERS_MAP})
would be the same, but since the the parameter map is passed the function can see this parameter and maybe do something else...
More likely however since the parameter map is passed to function, you may have scriptlet or other calls that set static fields, and when you have no result the call to loadFile is not working since these static fields have not been set.
So if it is not working passing "Disclosure" this is most certainly the case..
Have fun!