Crystal Report Viewer 11.5 Java SDK - How to set sub report parameter value

Question

Good day!
I have a report with 3 sub-reports in the detail section. Main report has two parameters and each sub-report has one parameter in turn. We have our own JSP to receive parameter values from the user. I am using the following code to do the parameter value setting later into the report. Parameter value setting works for main report, but not for the sub-report.
I get an Error, for the first sub-report, from the viewer saying:
The parameter 'parametername' does not allow null values
On this article: [article link|http://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sap.km.cm.docs/oss_notes_boj/sdn_oss_boj_bi/sap%28bd1lbizjptawmq==%29/bc/bsp/spn/scn_bosap/notes%7B6163636573733d36393736354636443646363436353344333933393338323636393736354637333631373036453646373436353733354636453735364436323635373233443330333033303331333233313337333233323331%7D.do]
It says to set the report name of the parameter field to the name of the sub report. On this aspect, assuming this tip/solution works, I would like to read the names of the sub-reports and their parameter names. I do not want to hard-code them into our application.
Here is my current code:
sdk.occa.report.data.Fields parameterFields = new Fields();
I have a HashMap of <parameterName, parameterValue>
Iterate through the map
report.data.ParameterField aParameterField = new ParameterField();
aParameterField.setReportName(""); //main report
report.data.Values theValues = new Values();
ParameterFieldDiscreteValue aParameterFieldDiscreteValue = new ParameterFieldDiscreteValue();
aParameterFieldDiscreteValue.setValue (aValue);
theValues.add(aParameterFieldDiscreteValue);
aParameterField.setName(parameterName)
aParameterField.setCurrentValues(theValues);
parameterFields.add(aParameterField);
viewer.setParameterFields(parameterFields);
Please look at the line:
aParameterField.setReportName(""); //main report
Here's where I would like to say
if (parameter is subreport's parameter) then setReportName(subreport name);
Thx

Answer 1

It was little difficult to navigate down the objects to find the sub reports and their parameters. I am attaching the code:
May be there are other ways to do the same.
public String getReportNameForParameter (String parameterName, ReportClientDocument reportClientDoc)
        String result = "";
        boolean found = false;
        try {
            SubreportController src = reportClientDoc.getSubreportController();
            DataDefController ddc = reportClientDoc.getDataDefController();
            IDataDefinition idd = ddc.getDataDefinition();
            Fields fs = idd.getParameterFields();
            Iterator fiter = fs.iterator();
            while (fiter.hasNext()) {
                IField ifld = (IField) fiter.next();
                if (parameterName.equals(ifld.getName())) {
                    found = true;
                //System.out.println ("\t Field Name/Description/HeadingText: " + ifld.getName() + "/" + ifld.getDescription() + "/" + ifld.getHeadingText());
            if (!found) {
                IStrings reportNames = src.getSubreportNames();
                //System.out.println ("  Sub Reports If Any ...");
                if (reportNames != null) {
                    Iterator iter = reportNames.iterator();
                    while (iter.hasNext()) {
                        String repName = (String) iter.next();
                        //System.out.println ("\t Sub Report Name " + repName);
                        ISubreportClientDocument srcd = src.getSubreport(repName);
                        ddc = srcd.getDataDefController();
                        idd = ddc.getDataDefinition();
                        fs = idd.getParameterFields();
                        fiter = fs.iterator();
                        while (fiter.hasNext()) {
                            IField ifld = (IField) fiter.next();
                            if (parameterName.equals(ifld.getName())) {
                                result = repName;
                                break;
                            //System.out.println ("\t\t Field Name/Description/HeadingText: " + ifld.getName() + "/" + ifld.getDescription() + "/" + ifld.getHeadingText());
        //System.out.println ("********************************************************** ");
        catch (Exception exc) {
            System.out.println ("Error/Exception while trying to find the report name for parameter [" + parameterName + "]");
            System.out.println ("*******************************************************************************************");
            exc.printStackTrace();
        return result;