Interfaces
Deque - a double ended queue, supporting
element insertion and removal at both ends. Extends the Queue interface.
BlockingDeque - a Deque with operations that
wait for the deque to become non-empty when retrieving an element, and wait for
space to become available in the deque when storing an element. Extends both
the Deque and BlockingQueue interfaces. (This interface is part of
java.util.concurrent.)
NavigableSet - a SortedSet extended with
navigation methods reporting closest matches for given search targets. A
NavigableSet may be accessed and traversed in either ascending or descending
order. This interface is intended to supersede the SortedSet interface.
NavigableMap - a SortedMap extended with
navigation methods returning the closest matches for given search targets. A
NavigableMap may be accessed and traversed in either ascending or descending
key order. This interface is intended to supersede the SortedMap interface.
ConcurrentNavigableMap - a ConcurrentMap that
is also a NavigableMap. (This interface is part of java.util.concurrent.)
Classes
ArrayDeque - efficient resizable-array
implementation of the Deque interface.
ConcurrentSkipListSet - concurrent scalable
skip list implementation of the NavigableSet interface.
ConcurrentSkipListMap - concurrent scalable
skip list implementation of the ConcurrentNavigableMap interface.
LinkedBlockingDeque - concurrent scalable
optionally bounded FIFO blocking deque backed by linked nodes.
AbstractMap.SimpleEntry - simple mutable
implementation of Map.Entry
AbstractMap.SimpleImmutableEntry - simple
immutable implementation of Map.Entry
These existing classes have been retrofitted
to implement new interfaces:
LinkedList - retrofitted to implement the
Deque interface.
TreeSet - retrofitted to implement the
NavigableSet interface.
TreeMap - retrofitted to implement the
NavigableMap interface.
Two new methods were added to the Collections
utility class:
newSetFromMap(Map) - creates a general
purpose Set implementation from a general purpose Map implementation.
There is no IdentityHashSet class, but
instead, just use
Set<Object> identityHashSet=
Collections.newSetFromMap(
new IdentityHashMap<Object, Boolean>());
asLifoQueue(Deque) - returns a view of a
Deque as a Last-in-first-out (Lifo) Queue.
The Arrays utility class now has methods
copyOf and copyOfRange that can efficiently resize, truncate, or copy subarrays
for arrays of all types.
Example
Before:
int[] newArray = new int[newLength];
System.arraycopy(oldArray, 0, newArray, 0,
oldArray.length);
After:
int[] newArray = Arrays.copyOf(a, newLength);
