A Castor question

[Karthik Veeramani]

I'm a beginner to castor. Im using a mapping file and marshalling some objects.
In a certain class, I have a HashSet member, that stores a collection of another object. I have getter and setter but they dont actually take in and return HashSets; rather their input is an array of objects. please see below.
eg.
class Test {
HashSet data; // say, this stores a set of objects of type MyObj.
public void setData(MyObj[] objs) {
// convert the array into hashset and store.
}
public MyObj[] getData () {
// convert the hashset to array and return.
}
}
when i try to marshall this object, i get an exception related to this field, like
"access resulted in exception: java.lang.reflect.InvocationTargetException"
My mapping file has the following lines, incase u need it -
<field name="data"<br /> type="packagename.MyObj"<br /> get-method="getData"<br /> set-method="setData"<br /> collection="array">
<bind-xml name="data"/>
</field>

Please tell me where I'm going wrong.