Package adams.core

Class WrapperHashSet<E>

  • Type Parameters:
    E - the type to store
    All Implemented Interfaces:
    Serializable, Iterable<E>, Collection<E>, Set<E>
    public class WrapperHashSet<E>
extends AbstractCollection<E>
implements Set<E>, Serializable
    An extended HashSet that wraps its objects in a wrapper object before storing them in a HashSet. The wrapper object uses the hashCode() method of the payload object in its equals(Object) method for comparison.
    Author:
    fracpete (fracpete at waikato dot ac dot nz)
    See Also:
    Serialized Form

    • Constructor Detail

      • WrapperHashSet

        public WrapperHashSet()
        Constructs a new, empty set; the backing HashMap instance has default initial capacity (16) and load factor (0.75).

      • WrapperHashSet

        public WrapperHashSet​(Collection<? extends E> c)
        Constructs a new set containing the elements in the specified collection. The HashMap is created with default load factor (0.75) and an initial capacity sufficient to contain the elements in the specified collection.
        Parameters:
        c - the collection whose elements are to be placed into this set
        Throws:
        NullPointerException - if the specified collection is null

      • WrapperHashSet

        public WrapperHashSet​(int initialCapacity,
                      float loadFactor)
        Constructs a new, empty set; the backing HashMap instance has the specified initial capacity and the specified load factor.
        Parameters:
        initialCapacity - the initial capacity of the hash map
        loadFactor - the load factor of the hash map
        Throws:
        IllegalArgumentException - if the initial capacity is less than zero, or if the load factor is nonpositive

      • WrapperHashSet

        public WrapperHashSet​(int initialCapacity)
        Constructs a new, empty set; the backing HashMap instance has the specified initial capacity and default load factor (0.75).
        Parameters:
        initialCapacity - the initial capacity of the hash table
        Throws:
        IllegalArgumentException - if the initial capacity is less than zero

    • Method Detail

      • clear

        public void clear()
        Removes all the elements from this set. The set will be empty after this call returns.
        Specified by:
        clear in interface Collection<E>
        Specified by:
        clear in interface Set<E>
        Overrides:
        clear in class AbstractCollection<E>

      • clone

        public Object clone()
        Returns a shallow copy of this HashSet instance: the elements themselves are not cloned.
        Overrides:
        clone in class Object
        Returns:
        a shallow copy of this set

      • contains

        public boolean contains​(Object o)
        Returns true if this set contains the specified element. More formally, returns true if and only if this set contains an element e such that (o==null ? e==null : o.equals(e)).
        Specified by:
        contains in interface Collection<E>
        Specified by:
        contains in interface Set<E>
        Overrides:
        contains in class AbstractCollection<E>
        Parameters:
        o - element whose presence in this set is to be tested
        Returns:
        true if this set contains the specified element

      • add

        public boolean add​(E e)
        Adds the specified element to this set if it is not already present. More formally, adds the specified element e to this set if this set contains no element e2 such that (e==null ? e2==null : e.equals(e2)). If this set already contains the element, the call leaves the set unchanged and returns false.
        Specified by:
        add in interface Collection<E>
        Specified by:
        add in interface Set<E>
        Overrides:
        add in class AbstractCollection<E>
        Parameters:
        e - element to be added to this set
        Returns:
        true if this set did not already contain the specified element

      • remove

        public boolean remove​(Object o)
        Removes the specified element from this set if it is present. More formally, removes an element e such that (o==null ? e==null : o.equals(e)), if this set contains such an element. Returns true if this set contained the element (or equivalently, if this set changed as a result of the call). (This set will not contain the element once the call returns.)
        Specified by:
        remove in interface Collection<E>
        Specified by:
        remove in interface Set<E>
        Overrides:
        remove in class AbstractCollection<E>
        Parameters:
        o - object to be removed from this set, if present
        Returns:
        true if the set contained the specified element

      • isEmpty

        public boolean isEmpty()
        Returns true if this set contains no elements.
        Specified by:
        isEmpty in interface Collection<E>
        Specified by:
        isEmpty in interface Set<E>
        Overrides:
        isEmpty in class AbstractCollection<E>
        Returns:
        true if this set contains no elements

      • size

        public int size()
        Returns the number of elements in this set (its cardinality).
        Specified by:
        size in interface Collection<E>
        Specified by:
        size in interface Set<E>
        Specified by:
        size in class AbstractCollection<E>
        Returns:
        the number of elements in this set (its cardinality)

      • toString

        public String toString()
        Returns a string representation of the stored objects.
        Overrides:
        toString in class AbstractCollection<E>
        Returns:
        the string representation