com.google.common.collect

Class ForwardingSet<E>

java.lang.Object

com.google.common.collect.ForwardingObject

com.google.common.collect.ForwardingCollection<E>

com.google.common.collect.ForwardingSet<E>

All Implemented Interfaces:

Iterable<E>, Collection<E>, Set<E>

Direct Known Subclasses:

ForwardingSortedSet, TypeToken.TypeSet

@GwtCompatible
public abstract class ForwardingSet<E>
extends ForwardingCollection<E>
implements Set<E>

A set which forwards all its method calls to another set. Subclasses should override one or more methods to modify the behavior of the backing set as desired per the decorator pattern.

Warning: The methods of ForwardingSet forward indiscriminately to the methods of the delegate. For example, overriding ForwardingCollection.add(E) alone will not change the behavior of ForwardingCollection.addAll(java.util.Collection<? extends E>), which can lead to unexpected behavior. In this case, you should override addAll as well, either providing your own implementation, or delegating to the provided standardAddAll method.

default method warning: This class does not forward calls to default methods. Instead, it inherits their default implementations. When those implementations invoke methods, they invoke methods on the ForwardingSet.

The standard methods are not guaranteed to be thread-safe, even when all of the methods that they depend on are thread-safe.

Since:

2.0

Author:

Kevin Bourrillion, Louis Wasserman

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ForwardingSet() Constructor for use by subclasses.

Method Summary

Modifier and Type	Method and Description
protected abstract Set<E>	delegate() Returns the backing delegate instance that methods are forwarded to.
boolean	equals(Object object)
int	hashCode()
protected boolean	standardEquals(Object object) A sensible definition of equals(java.lang.Object) in terms of ForwardingCollection.size() and ForwardingCollection.containsAll(java.util.Collection<?>).
protected int	standardHashCode() A sensible definition of hashCode() in terms of ForwardingCollection.iterator().
protected boolean	standardRemoveAll(Collection<?> collection) A sensible definition of ForwardingCollection.removeAll(java.util.Collection<?>) in terms of ForwardingCollection.iterator() and ForwardingCollection.remove(java.lang.Object).

Methods inherited from class com.google.common.collect.ForwardingCollection

add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, standardAddAll, standardClear, standardContains, standardContainsAll, standardIsEmpty, standardRemove, standardRetainAll, standardToArray, standardToArray, standardToString, toArray, toArray

Methods inherited from class com.google.common.collect.ForwardingObject

toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Set

add, addAll, clear, contains, containsAll, isEmpty, iterator, remove, removeAll, retainAll, size, spliterator, toArray, toArray

Methods inherited from interface java.util.Collection

parallelStream, removeIf, stream

Methods inherited from interface java.lang.Iterable

forEach

Constructor Detail

ForwardingSet

protected ForwardingSet()

Constructor for use by subclasses.

Method Detail

delegate

protected abstract Set<E> delegate()

Description copied from class: ForwardingObject

Returns the backing delegate instance that methods are forwarded to. Abstract subclasses generally override this method with an abstract method that has a more specific return type, such as delegate(). Concrete subclasses override this method to supply the instance being decorated.

Specified by:

delegate in class ForwardingCollection<E>

equals

public boolean equals(@Nullable
                      Object object)

Specified by:

equals in interface Collection<E>

Specified by:

equals in interface Set<E>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<E>

Specified by:

hashCode in interface Set<E>

Overrides:

hashCode in class Object

standardRemoveAll

protected boolean standardRemoveAll(Collection<?> collection)

A sensible definition of ForwardingCollection.removeAll(java.util.Collection<?>) in terms of ForwardingCollection.iterator() and ForwardingCollection.remove(java.lang.Object). If you override iterator or remove, you may wish to override ForwardingCollection.removeAll(java.util.Collection<?>) to forward to this implementation.

Overrides:

standardRemoveAll in class ForwardingCollection<E>

Since:

7.0 (this version overrides the ForwardingCollection version as of 12.0)

standardEquals

protected boolean standardEquals(@Nullable
                                 Object object)

A sensible definition of equals(java.lang.Object) in terms of ForwardingCollection.size() and ForwardingCollection.containsAll(java.util.Collection<?>). If you override either of those methods, you may wish to override equals(java.lang.Object) to forward to this implementation.

Since:

7.0

standardHashCode

protected int standardHashCode()

A sensible definition of hashCode() in terms of ForwardingCollection.iterator(). If you override ForwardingCollection.iterator(), you may wish to override equals(java.lang.Object) to forward to this implementation.

Since:

7.0