Object corruption when retrieving object from List

Question

Hi,
We have a batch program. There are muliple threads running which read data from database and then processes the data.
In each thread. there is a call to fetch data from a table, create objects and populate a list and return it.
This list is then given to another method which processes each item from the list
This is a simplified version of what the code looks like.
public class Manager{
     public void run(){
          Reader r = new Reader();
          Processor processor = new Processor();
          List list = reader.getItems();
          processor.processItem(list);
public class Reader{
     public List getItems(){
          List list = new ArrayList();
          // Resultset rs = execute a query and get
// a resultset object
          while(rs.next()){
               Item item = new Item();
               // set information from rs and set
//into item
               list.add(item);
          return list;
public class Processor {
     public processItem(List list){
          Item item = null;
          while (!list.isEmpty()){
               item = (Item)list.remove(0);
In the processItem method of Processor class, when I retrieve item from the List
it should return me an object of type Item. But very rarely what happens is that
the object I return is not of type Item, but null or a junk class like [C@1309b55.
Once this happens, i get a class cast exception when i am trying to cast this to
Item class.
Can anyone please tell me if you have encountered such a scenario before?
The process is running in a 2 processor environment.
It's mulithreaded, but method calls are done from within a thread.
The ArrayList is not shared across multiple threads. It's life starts
and ends within the run method of the thread.

Answer 1

Item class is made up of three instances of three
separate classes with corresponding getters and
setters.
All these 3 classes, have member variables of String,
int and double.
There are getter and setter methods for all of the
variables as well as overridden equals and hashcode
methodsYou have to show your code, inside [code] and [/code] tags.