Class ForwardingSet<E extends @Nullable Object>

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 @Nullable Object>
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(Collection), 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	Description
protected	ForwardingSet()	Constructor for use by subclasses.

Method Summary

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

Methods inherited from class ForwardingCollection

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

Modifier and Type	Method	Description
boolean	add(E element)
boolean	addAll(Collection<? extends E> collection)
void	clear()
boolean	contains(@Nullable Object object)
boolean	containsAll(Collection<?> collection)
boolean	isEmpty()
Iterator<E>	iterator()
boolean	remove(@Nullable Object object)
boolean	removeAll(Collection<?> collection)
boolean	retainAll(Collection<?> collection)
int	size()
protected boolean	standardAddAll(Collection<? extends E> collection)	A sensible definition of ForwardingCollection.addAll(Collection) in terms of ForwardingCollection.add(E).
protected void	standardClear()	A sensible definition of ForwardingCollection.clear() in terms of ForwardingCollection.iterator(), using the iterator's remove method.
protected boolean	standardContains(@Nullable Object object)	A sensible definition of ForwardingCollection.contains(Object) in terms of ForwardingCollection.iterator().
protected boolean	standardContainsAll(Collection<?> collection)	A sensible definition of ForwardingCollection.containsAll(Collection) in terms of ForwardingCollection.contains(Object) .
protected boolean	standardIsEmpty()	A sensible definition of ForwardingCollection.isEmpty() as !iterator().hasNext.
protected boolean	standardRemove(@Nullable Object object)	A sensible definition of ForwardingCollection.remove(Object) in terms of ForwardingCollection.iterator(), using the iterator's remove method.
protected boolean	standardRetainAll(Collection<?> collection)	A sensible definition of ForwardingCollection.retainAll(Collection) in terms of ForwardingCollection.iterator(), using the iterator's remove method.
protected @Nullable Object[]	standardToArray()	A sensible definition of ForwardingCollection.toArray() in terms of ForwardingCollection.toArray(Object[]).
protected <T extends @Nullable Object> T[]	standardToArray(T[] array)	A sensible definition of ForwardingCollection.toArray(Object[]) in terms of ForwardingCollection.size() and ForwardingCollection.iterator().
protected String	standardToString()	A sensible definition of ForwardingObject.toString() in terms of ForwardingCollection.iterator().
@Nullable Object[]	toArray()
<T extends @Nullable Object> T[]	toArray(T[] array)

Methods inherited from class ForwardingObject

toString

Modifier and Type	Method	Description
String	toString()	Returns the string representation generated by the delegate's toString method.

Methods inherited from class Object

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

Methods inherited from interface Collection

parallelStream, removeIf, stream, toArray

Methods inherited from interface Iterable

forEach

Methods inherited from interface Set

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

Constructor Details

ForwardingSet

protected ForwardingSet()

Constructor for use by subclasses.

Method Details

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 extends @Nullable Object>

equals

public boolean equals(@Nullable Object object)

Specified by:

equals in interface Collection<E extends @Nullable Object>

Specified by:

equals in interface Set<E extends @Nullable Object>

Overrides:

equals in class Object

hashCode

public int hashCode()

Specified by:

hashCode in interface Collection<E extends @Nullable Object>

Specified by:

hashCode in interface Set<E extends @Nullable Object>

Overrides:

hashCode in class Object

standardRemoveAll

protected boolean standardRemoveAll(Collection<?> collection)

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

Overrides:

standardRemoveAll in class ForwardingCollection<E extends @Nullable Object>

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(Object) in terms of ForwardingCollection.size() and ForwardingCollection.containsAll(Collection). If you override either of those methods, you may wish to override equals(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(Object) to forward to this implementation.

Since:

7.0