Pass Fields to Subreports in Jasper Reports

I am using Jasper-Reports 5.2.0 and have a main Report containing 2 sub-reports.

I have a Model ReportData which contains two attributes: List<Feld> felder and List<Wert> werte. The two sub-models contain multiple attributes with data to be displayed in a table.

So this is how I pass my Datasource to the sub-reports.

<subreport>
        <reportElement x="0" y="28" width="553" height="51" uuid="502d9559-e6bf-49c8-a34c-ffb8916634cd"/>
        <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F(werte)]]></dataSourceExpression>
        <subreportExpression><![CDATA["werte_subreport.jasper"]]></subreportExpression>
</subreport>

<subreport>
        <reportElement x="0" y="90" width="555" height="50" uuid="5e5b0287-5002-4e31-aa8f-afe36ea78827"/>
        <dataSourceExpression><![CDATA[new net.sf.jasperreports.engine.data.JRBeanCollectionDataSource($F(felder))]]></dataSourceExpression>
        <subreportExpression><![CDATA["felder_subreport.jasper"]]></subreportExpression>
</subreport>

and this is how I fill my report (datasource is the Collection of ReportData):

printable = JasperFillManager.fillReport(PropertyLoader.getSingleton().loadAsInputStream(REPORT_FOLDER + File.separatorChar + KONFIG_JASPER),parameters, datasource);

Somehow my values are not passed to the sub-reports and Jasper Reports is trying to use attributes as defaultWert, which isn't part of the Class Wert and should be displayed in the sub-report.

net.sf.jasperreports.engine.JRException: Error retrieving field value from bean : defaultWert
Caused by: java.lang.NoSuchMethodException: Unknown property 'defaultWert' on class XXXXXXXXXXXXXXXXXXXXXX.model.ReportData'

I defined the two Lists werte and felder as fields of type java.util.List in the Main Report and defined the attributes as for defaultWert as fields of type String in the sub-reports. What am I doing wrong?

Solution

Thanks for your replies, I just found the problem... it was a stupid syntax mistake... it has to be $F{felder} instead of $F(felder) in my JRExpression... it ist working fine now!