Caminar una colección
Mucho ojo al tratar de caminar una colección:
ConcurrentModificationException This exception may be thrown by methods that have detected concurrent
modification of an object when such modification is not permissible.
…
Note that this exception does not always indicate that an object has
been concurrently modified by a /different/ thread. If a single thread
issues a sequence of method invocations that violates the contract of an
object, the object may throw this exception. For example, if a thread
modifies a collection directly while it is iterating over the collection
with a fail-fast iterator, the iterator will thow this exception.http://java.sun.com/j2se/1.4.2/docs/api/java/util/ConcurrentModificationException.html
Esto es culpa del Iterator a traves del cual recorremos la clase (por mas que usemos un “enhanced for” en el fondo sigue habiendo un iterator) y hay que recordar que no se puede modificar una lista, agregando o eliminando objetos, mientras la estamos recorriendo con un iterator.
