JDK源码学习：Collection

public interface Collection<E> extends Iterable<E> {
  int size;
  boolean isEmpty();
  boolean contains(Object o);
  Iterator<E> iterator();
  Object[] toArray();
  <T> T[] toArray(T[] a);
  boolean add(E e);
  boolean remove(Object o);
  boolean containsAll(Collection<?> c);
  boolean addAll(Collection<? extends E> c);
  boolean removeAll(Collection<?> c);

  default boolean removeIf(Predicate<? super E> filter) {
    ...
  }

  boolean retainAll(Collection<?> c);
  void clear();
  boolean equals(Object o);
  int hashCode();

  default Spliterator<E> spliterator() {
    ...
  }

  default Stream<E> stream() {
    ...
  }

  default Stream<E> parallelStream() {
    ...
  }
}

public interface Iterable<T> {
  Iterator<T> iterator();

  default forEach(Consumer<? super T> action) {
    ...
  }

  default Spliterator<T> spliterator() {
    ...
  }
}

public interface Iterator<E> {
  boolean hasNext();
  E next();

  default void remove() {
    ...
  }

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