Appendix A: Collections API Reference This appendix presents information to help you navigate through the classes in the Java Collections Framework. Class, Method, and Field Index Table A−1 provides an index to all the classes, methods, and fields in the Java Collections Framework. Classes specify which package they are in, while methods and fields specify what classes they belong to. For detailed information about the classes, methods, and fields, see the chapters that describe them. Table A−1: Summary of Collection Framework Classes, Methods, and Fields CLASS/METHOD/FIELD NAME PACKAGE/CLASS FOR CLASS/METHOD/FIELD A AbstractCollection java.util AbstractList java.util AbstractMap java.util AbstractSequentialList java.util AbstractSet java.util add() AbstractCollection, AbstractList, AbstractSequentialList, ArrayList, Collection, HashSet, LinkedList, List, ListIterator, Set, TreeSet, Vector addAll() AbstractCollection, AbstractList, AbstractSequentialList, ArrayList, Collection, LinkedList, List, Set, TreeSet, Vector addElement() Vector addFirst() LinkedList addLast() LinkedList and() BitSet andNot() BitSet ArrayList java.util Arrays java.util asList() Arrays B binarySearch() Arrays, Collections BitSet java.util C capacity() Vector capacityIncrement Vector clear() AbstractCollection, AbstractList, AbstractMap, ArrayList, BitSet, Collection, HashMap, HashSet, Hashtable, LinkedList, 250 List, Map, Set, TreeMap, TreeSet, Vector, WeakHashMap clone() ArrayList, BitSet, HashMap, HashSet, Hashtable, LinkedList, TreeMap, TreeSet, Vector Collection java.util Collections java.util Comparable java.lang Comparator java.util comparator() SortedMap, SortedSet, TreeMap, TreeSet compare() Comparator compareTo() Comparable contains() AbstractCollection, ArrayList, Collection, HashSet, Hashtable, LinkedList, List, Set, TreeSet, Vector containsAll() AbstractCollection, Collection, List, Set, Vector containsKey() AbstractMap, HashMap, Hashtable, Map, TreeMap, WeakHashMap containsValue() AbstractMap, HashMap, Hashtable, Map, TreeMap copy() Collections copyInto() Vector D defaults Properties Dictionary java.util E elementAt() Vector elementCount Vector elementData Vector elements() Dictionary, Hashtable, Vector empty() Stack EMPTY_LIST Collections EMPTY_MAP Collections EMPTY_SET Collections ensureCapacity() ArrayList, Vector entrySet() AbstractMap, HashMap, Hashtable, Map, TreeMap, WeakHashMap Enumeration java.util enumeration() Collections equals() AbstractList, AbstractMap, AbstractSet, Arrays, BitSet, Collection, Comparator, Hashtable, List, Map, Map.Entry, Set, Vector F fill() Arrays, Collections first() SortedSet, TreeSet firstElement() Vector Appendix A: Collections API Reference 251 firstKey() SortedMap, TreeMap G get() AbstractList, AbstractMap, AbstractSequentialList, ArrayList, BitSet, Dictionary, HashMap, Hashtable, LinkedList, List, Map, TreeMap, Vector, WeakHashMap getFirst() LinkedList getKey() Map.Entry getLast() LinkedList getProperty() Properties getValue() Map.Entry H hashCode() AbstractList, AbstractMap, AbstractSet, BitSet, Collection, Hashtable, List, Map, Map.Entry, Set, Vector HashMap java.util HashSet java.util Hashtable java.util hasMoreElements() Enumeration hasNext() Iterator, ListIterator hasPrevious() ListIterator headMap() SortedMap, TreeMap headSet() SortedSet, TreeSet I indexOf() AbstractList, ArrayList, LinkedList List, Vector insertElementAt() Vector isEmpty() AbstractCollection, AbstractMap, ArrayList, Collection, Dictionary, HashMap, HashSet, Hashtable, List, Map, Set, TreeSet, Vector, WeakHashMap Iterator java.util iterator() AbstractCollection, AbstractList, AbstractSequentialList, Collection, HashSet, List, Set, TreeSet K keys() Dictionary, Hashtable keySet() AbstractMap, HashMap, Hashtable, Map, TreeMap L last() SortedSet, TreeSet lastElement() Vector lastIndexOf() AbstractList, ArrayList, LinkedList, List, Vector lastKey() SortedMap, TreeMap length() BitSet LinkedList java.util List java.util list() Properties Appendix A: Collections API Reference 252 ListIterator java.util listIterator() AbstractList, AbstractSequentialList, LinkedList, List load() Properties M Map java.util Map.Entry java.util max() Collections min() Collections modCount AbstractList N nCopies() Collections next() Iterator, ListIterator nextElement() Enumeration nextIndex() ListIterator O or() BitSet P peek() Stack pop() Stack previous() ListIterator previousIndex() ListIterator Properties java.util propertyNames() Properties push() Stack put() AbstractMap, Dictionary, HashMap, Hashtable, Map, TreeMap, WeakHashMap putAll() AbstractMap, HashMap, Hashtable, Map, TreeMap R rehash() Hashtable remove() AbstractCollection, AbstractList, AbstractMap, AbstractSequentialList, ArrayList, Collection, Dictionary, HashMap, HashSet, Hashtable, Iterator, LinkedList, List, ListIterator, Map, Set, TreeMap, TreeSet, Vector, WeakHashMap removeAll() AbstractCollection, AbstractSet, Collection, List, Set, Vector removeAllElements() Vector removeElement() Vector removeElementAt() Vector removeFirst() LinkedList removeLast() LinkedList removeRange() AbstractList, ArrayList, Vector retainAll() AbstractCollection, Collection, List, Set, Vector Appendix A: Collections API Reference 253 reverse() Collections reverseOrder() Collections S save() Properties search() Stack Set java.util set() AbstractList, AbstractSequentialList, ArrayList, BitSet, LinkedList, List, ListIterator, Vector setElementAt() Vector setProperty() Properties setSize() Vector setValue() Map.Entry shuffle() Collections singleton() Collections singletonList() Collections singletonMap() Collections size() AbstractCollection, AbstractMap, ArrayList, BitSet, Collection, Dictionary, HashMap, HashSet, Hashtable, LinkedList, List, Map, Set, TreeMap, TreeSet, Vector, WeakHashMap sort() Arrays, Collections SortedMap java.util SortedSet java.util Stack java.util store() Properties subList() AbstractList, List, Vector subMap() SortedMap, TreeMap subSet() SortedSet, TreeSet synchronizedCollection() Collections synchronizedList() Collections synchronizedMap() Collections synchronizedSet() Collections synchronizedSortedMap() Collections synchronizedSortedSet() Collections T tailMap() SortedMap, TreeMap tailSet() SortedSet, TreeSet toArray() AbstractCollection, ArrayList, Collection, LinkedList, List, Set, Vector toString() AbstractCollection, AbstractMap, BitSet, Hashtable, Vector TreeMap java.util TreeSet java.util Appendix A: Collections API Reference 254 trimToSize() ArrayList, Vector U unmodifiableCollection() Collections unmodifiableList() Collections unmodifiableMap() Collections unmodifiableSet() Collections unmodifiableSortedMap() Collections unmodifiableSortedSet() Collections V values() AbstractMap, HashMap, Hashtable, Map, TreeMap Vector java.util W WeakHashMap java.util X xor() BitSet Class−Level API Index In the tables that follow, you'll find the class summary tables from the earlier chapters recreated in a common location for easy reference. They list the constructors, methods, and fields of each class in the Collections Framework. For those constructors, methods, and fields that are protected, you'll find them listed in italic. In all cases, the version of Java that the constructor, method, or field was introduced is mentioned as well as a short description. AbstractCollection Class Table A−2: Summary of the AbstractCollection Class VARIABLE/METHOD NAME VERSION DESCRIPTION AbstractCollection() 1.2 Constructs an empty (abstract) collection. add() 1.2 Adds an element to the collection. addAll() 1.2 Adds a collection of elements to the collection. clear() 1.2 Clears all elements from the collection. contains() 1.2 Checks if the collection contains an element. containsAll() 1.2 Checks if the collection contains a collection of elements. isEmpty() 1.2 Checks if the collection is empty. iterator() 1.2 Returns an object from the collection that allows all of the collection's elements to be visited. remove() 1.2 Clears a specific element from the collection. removeAll() 1.2 Clears a collection of elements from the collection. retainAll() 1.2 Removes all elements from collection not in another collection. size() 1.2 Returns the number of elements in a collection. Class−Level API Index 255 toArray() 1.2 Returns the elements of the collection as an array. toString() 1.2 Converts the collection contents into a string. AbstractList Class Table A−3: Summary of the AbstractList Class VARIABLE/METHOD NAME VERSION DESCRIPTION AbstractList() 1.2 Constructs an empty (abstract) list. modCount 1.2 Used by iterator to check for concurrent modifications of the list. add() 1.2 Adds an element to the list. addAll() 1.2 Adds a collection of elements to the list. clear() 1.2 Clears all elements from the list. equals() 1.2 Checks for equality with another object. get() 1.2 Returns an element at a specific position. hashCode() 1.2 Returns the computed hash code for a list. indexOf() 1.2 Searches for an element within the list. iterator() 1.2 Returns an object from the list that allows all of the list's elements to be visited. lastIndexOf() 1.2 Searches from the end of the list for an element. listIterator() 1.2 Returns an object from the collection that allows all of the list's elements to be visited sequentially. remove() 1.2 Clears a specific element from the list. removeRange() 1.2 Clears a range of elements from the list. set() 1.2 Changes an element at a specific position within the list. subList() 1.2 Returns a portion of the list. AbstractMap Class Table A−4: Summary of the AbstractMap Class VARIABLE/METHOD NAME VERSION DESCRIPTION AbstractMap() 1.2 Constructs an empty (abstract) map. clear() 1.2 Removes all the elements from the map. containsKey() 1.2 Checks to see if an object is a key within the map. containsValue() 1.2 Checks to see if an object is a value within the map. entrySet() 1.2 Returns the set of key−value pairs in the map. equals() 1.2 Checks for equality with another object. get() 1.2 Retrieves a value for a key in the map. hashCode() 1.2 Computes a hash code for the map. AbstractList Class 256 isEmpty() 1.2 Checks if the map has any elements. keySet() 1.2 Retrieves a collection of the keys of the hash table. put() 1.2 Places a key−value pair into the map. putAll() 1.2 Places a collection of key−value pairs into the map. remove() 1.2 Removes an element from the map. size() 1.2 Returns the number of elements in the map. toString() 1.2 Converts the map contents into a string. values() 1.2 Retrieves a collection of the values of the map. AbstractSequentialList Class Table A−5: Summary of the AbstractSequentialList Class VARIABLE/METHOD NAME VERSION DESCRIPTION AbstractSequentialList() 1.2 Constructs an empty sequential list. add() 1.2 Adds an element to the list. addAll() 1.2 Adds a collection of elements to the list. get() 1.2 Returns an element at a specific position. iterator() 1.2 Returns an object from the list that allows all of the list's elements to be visited. listIterator() 1.2 Returns an object from the list that allows all of the list's elements to be visited sequentially. remove() 1.2 Clears a specific element from the list. set() 1.2 Changes an element at a specific position within the list. AbstractSet Class Table A−6: Summary of the AbstractSet Class VARIABLE/METHOD NAME VERSION DESCRIPTION AbstractSet() 1.2 Constructs an empty set. equals() 1.2 Checks for equality with another object. hashCode() 1.2 Computes a hash code for the set. removeAll() 1.2 Clears a collection of elements from the set. ArrayList Class Table A−7: Summary of the ArrayList Class VARIABLE/METHOD NAME VERSION DESCRIPTION ArrayList() 1.2 Constructs an empty list backed by an array. AbstractSequentialList Class 257 add() 1.2 Adds an element to the list. addAll() 1.2 Adds a collection of elements to the list. clear() 1.2 Clears all elements from the list. clone() 1.2 Creates a clone of the list. contains() 1.2 Checks to see if an object is a value within the list. ensureCapacity() 1.2 Ensures capacity of internal buffer is at least a certain size. get() 1.2 Returns an element at a specific position. indexOf() 1.2 Searches for an element within the list. isEmpty() 1.2 Checks if list has any elements. lastIndexOf() 1.2 Searches from end of list for an element. remove() 1.2 Clears a specific element from the list. removeRange() 1.2 Clears a range of elements from the list. set() 1.2 Changes an element at a specific position within the list. size() 1.2 Returns the number of elements in the list. toArray() 1.2 Returns elements of the list as an array. trimToSize() 1.2 Trims capacity of internal buffer to actual size. Arrays Class Table A−8: Summary of the Arrays Class VARIABLE/METHOD NAME VERSION DESCRIPTION asList() 1.2 Converts an array to a list. binarySearch() 1.2 Searches for an element within an array. equals() 1.2 Checks for equality of two arrays. fill() 1.2 Fills an array with a single element. sort() 1.2 Sorts the elements of an array. BitSet Class Table A−9: Summary of the BitSet Class VARIABLE/METHOD NAME VERSION DESCRIPTION BitSet() 1.0 Creates a bit set with all bits clear. and() 1.0 Performs a logical AND operation with another bit set. andNot() 1.2 Performs a logical NOT operation of another bit set, then performs a logical AND operation with this bit Arrays Class 258 set. clear() 1.0 Clears a specific bit from the set. clone() 1.0 Copies the bit set. equals() 1.0 Checks for equality with another object. get() 1.0 Gets the setting of a specific bit from the set. hashCode() 1.0 Returns computed hash code for the bit set. length() 1.2 Returns the logical size of the set. or() 1.0 Performs a logical OR operation with another bit set. set() 1.0 Sets a specific bit of the set. size() 1.0 Returns the internal space used to represent the bit set. toString() 1.0 Converts the bit set contents into a string. xor() 1.0 Performs a logical XOR operation with another bit set. Collection Interface Table A−10: Summary of the Collection Interface VARIABLE/METHOD NAME VERSION DESCRIPTION add() 1.2 Adds an element to the collection. addAll() 1.2 Adds a collection of elements to the collection. clear() 1.2 Clears all elements from the collection. contains() 1.2 Checks if a collection contains an element. containsAll() 1.2 Checks if a collection contains a collection of elements. equals() 1.2 Checks for equality with another object. hashCode() 1.2 Returns the computed hash code for the collection. isEmpty() 1.2 Checks if a collection is empty. iterator() 1.2 Returns an object from the collection that allows all of the collection's elements to be visited. remove() 1.2 Clears a specific element from collection. removeAll() 1.2 Clears a collection of elements from the collection. retainAll() 1.2 Removes all elements from the collection not in another collection. size() 1.2 Returns the number of elements in the collection. toArray() 1.2 Returns the elements of a collection as an array. Collections Class Table A−11: Summary of the Collections Class VARIABLE/METHOD NAME VERSION DESCRIPTION Collection Interface 259 . Collections API Reference 254 trimToSize() ArrayList, Vector U unmodifiableCollection() Collections unmodifiableList() Collections unmodifiableMap() Collections. synchronizedCollection() Collections synchronizedList() Collections synchronizedMap() Collections synchronizedSet() Collections synchronizedSortedMap() Collections