how to pass List<Long> in Ireport

Hi,

i have this query:

{
    "collectionName" : "dayid_instanceid",
    'findQuery' : {
        '_id.day_id' : { '$gte' : $P{start_date_param} ,'$lt' : $P{end_date_param} },
        '_id.instance_id' : { '$in' : $P{instance_id_param} }
    },
    "sort" :
    {
        "_id" : 1
    }

}

the parameters are:

<parameter name="end_date_param" class="java.util.Date"/>
<parameter name="start_date_param" class="java.util.Date"/>
<parameter name="instance_id_param" class="java.util.Collection"/>

when i run the report

I insert to the "instance_id_param" these values: -903099689, -913099689

and i get this:

{
    "collectionName" : "dayid_instanceid",
    'findQuery' : {
        '_id.day_id' : { '$gte' : {'start_date_param':null} ,'$lt' : {'end_date_param':null} },
        '_id.instance_id' : { '$in' : ['-903099689', '-913099689'] }
    },
    "sort" :
    {
        "_id" : 1
    }
}

so it take the "instance_id_param" as String not as long.

help please.

Izek