Interface Iterator<E>

Type Parameters:

E - the type of elements returned by this iterator

All Known Subinterfaces:

ListIterator<E>, PrimitiveIterator<T,T_CONS>, PrimitiveIterator.OfDouble, PrimitiveIterator.OfInt, PrimitiveIterator.OfLong, XMLEventReader

All Known Implementing Classes:

BeanContextSupport.BCSIterator, EventReaderDelegate, Scanner

public interface Iterator<E>

Since:

1.2

See Also:

Collection, ListIterator, Iterable

Methods

hasNext

boolean hasNext()

Returns true if the iteration has more elements. (In other words, returns true if next() would return an element rather than throwing an exception.)

Returns:

true if the iteration has more elements

next

E next()

Returns the next element in the iteration.

Returns:

the next element in the iteration

Throws:

NoSuchElementException - if the iteration has no more elements

remove

default void remove()

Removes from the underlying collection the last element returned by this iterator (optional operation). This method can be called only once per call to next(). The behavior of an iterator is unspecified if the underlying collection is modified while the iteration is in progress in any way other than by calling this method.

Implementation Requirements:

The default implementation throws an instance of UnsupportedOperationException and performs no other action.

Throws:

UnsupportedOperationException - if the remove operation is not supported by this iterator

IllegalStateException - if the next method has not yet been called, or the remove method has already been called after the last call to the next method

forEachRemaining

default void forEachRemaining(Consumer<? super E> action)

Performs the given action for each remaining element until all elements have been processed or the action throws an exception. Actions are performed in the order of iteration, if that order is specified. Exceptions thrown by the action are relayed to the caller.

Implementation Requirements:

The default implementation behaves as if:

while (hasNext())
         action.accept(next());

Parameters:

action - The action to be performed for each element

Throws:

NullPointerException - if the specified action is null

Since:

1.8