// Java can guarantee that the Object read back
// is indeed an ArrayList of some sort of Objects, just not what type of Objects.
// The array internal to the ArrayList is Object[], not Thing[], so that is no help
// in ensuring the Object read back is an ArrayList<Thing>.
// We verify the objects in the ArrayList individually.
// This is safer but considerably slower than suppressing the error message.

// Does not generate a cast warning.
final ArrayList<Object> temp = (ArrayList<Object>)ois.readObject();
final ArrayList<Thing>things = new ArrayList<Thing>( temp.size() );
for ( Object item : temp )
   things.add( (Thing)item );