Passing list in Map

[bibinjacob]

I have some doubt in jasper subreport.See i have somethinng like:

HashMap<String,List> map = new HashMap<String,List>();

List<ObjectA> list = new ArrayList<ObjectA>();

ObjectA a =new ObjectA();

a.setId(1);

a.setName("nachname");

list.add(a);(//Similary one or more objects are added.)

map.put("object1",list);(//Similary one or more lists are added to map.)

I want to use the data in a crosstab.How can i use it.

Is it like passing a map to first report.In first report placing a subreport which passes the list in map.(If so where should i place the subreport-is it detail band;since i have iterate through map.Again in subreport i have to iterate.Is it necessary that i should point to .jasper file in subreport expression or can i point to .jrxml.If so how to give path.)

Finally i should place the crosstab in subreport.Will this work???

If anybody knows answer please reply back

regards

bj