totalcross.util

Class AbstractSet4D<E>

java.lang.Object

totalcross.util.AbstractCollection4D<E>

totalcross.util.AbstractSet4D<E>

All Implemented Interfaces:

java.lang.Iterable<E>, java.util.Collection<E>, java.util.Set<E>

public abstract class AbstractSet4D<E>
extends AbstractCollection4D<E>
implements java.util.Set<E>

An abstract implementation of Set to make it easier to create your own implementations. In order to create a Set, subclass AbstractSet and implement the same methods that are required for AbstractCollection (although these methods must of course meet the requirements that Set puts on them - specifically, no element may be in the set more than once). This class simply provides implementations of equals() and hashCode() to fulfil the requirements placed on them by the Set interface.

Since:

1.2

See Also:

Collection, AbstractCollection, Set, HashSet, TreeSet, LinkedHashSet

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractSet4D() The main constructor, for use by subclasses.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o) Tests whether the given object is equal to this Set.
int	hashCode() Returns a hash code for this Set.
boolean	removeAll(java.util.Collection<?> c) Removes from this set all elements in the given collection (optional operation).

Methods inherited from class totalcross.util.AbstractCollection4D

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

AbstractSet4D

protected AbstractSet4D()

The main constructor, for use by subclasses.

Method Detail

equals

public boolean equals(java.lang.Object o)

Tests whether the given object is equal to this Set. This implementation first checks whether this set is the given object, and returns true if so. Otherwise, if o is a Set and is the same size as this one, it returns the result of calling containsAll on the given Set. Otherwise, it returns false.

Specified by:

equals in interface java.util.Collection<E>

Specified by:

equals in interface java.util.Set<E>

Overrides:

equals in class java.lang.Object

Parameters:

o - the Object to be tested for equality with this Set

Returns:

true if the given object is equal to this Set

hashCode

public int hashCode()

Returns a hash code for this Set. The hash code of a Set is the sum of the hash codes of all its elements, except that the hash code of null is defined to be zero. This implementation obtains an Iterator over the Set, and sums the results.

Specified by:

hashCode in interface java.util.Collection<E>

Specified by:

hashCode in interface java.util.Set<E>

Overrides:

hashCode in class java.lang.Object

Returns:

a hash code for this Set

removeAll

public boolean removeAll(java.util.Collection<?> c)

Removes from this set all elements in the given collection (optional operation). This implementation uses size() to determine the smaller collection. Then, if this set is smaller, it iterates over the set, calling Iterator.remove if the collection contains the element. If this set is larger, it iterates over the collection, calling Set.remove for all elements in the collection. Note that this operation will fail if a remove methods is not supported.

Specified by:

removeAll in interface java.util.Collection<E>

Specified by:

removeAll in interface java.util.Set<E>

Overrides:

removeAll in class AbstractCollection4D<E>

Parameters:

c - the collection of elements to remove

Returns:

true if the set was modified as a result

Throws:

java.lang.UnsupportedOperationException - if remove is not supported

java.lang.NullPointerException - if the collection is null

See Also:

AbstractCollection.remove(Object), Collection.contains(Object), Iterator.remove()