src/share/classes/java/util/Collections.java
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rev 7019 : 7129185: Add Collections.{checked|empty|unmodifiable}Navigable{Map|Set}
Reviewed-by: duke
*** 1210,1219 ****
--- 1210,1283 ----
public E first() {return ss.first();}
public E last() {return ss.last();}
}
/**
+ * Returns an unmodifiable view of the specified navigable set. This method
+ * allows modules to provide users with "read-only" access to internal
+ * navigable sets. Query operations on the returned navigable set "read
+ * through" to the specified navigable set. Attempts to modify the returned
+ * navigable set, whether direct, via its iterator, or via its
+ * <tt>subSet</tt>, <tt>headSet</tt>, or <tt>tailSet</tt> views, result in
+ * an <tt>UnsupportedOperationException</tt>.<p>
+ *
+ * The returned navigable set will be serializable if the specified sorted set
+ * is serializable.
+ *
+ * @param s the navigable set for which an unmodifiable view is to be
+ * returned
+ * @return an unmodifiable view of the specified navigable set
+ * @since 1.8
+ */
+ public static <T> NavigableSet<T> unmodifiableNavigableSet(NavigableSet<T> s) {
+ return new UnmodifiableNavigableSet<>(s);
+ }
+
+ /**
+ * @serial include
+ */
+ static class UnmodifiableNavigableSet<E>
+ extends UnmodifiableSortedSet<E>
+ implements NavigableSet<E>, Serializable {
+
+ private final NavigableSet<E> ns;
+
+ UnmodifiableNavigableSet(NavigableSet<E> s) {super(s); ns = s;}
+
+ @Override public E lower(E e) { return ns.lower(e); }
+ @Override public E floor(E e) { return ns.floor(e); }
+ @Override public E ceiling(E e) { return ns.ceiling(e); }
+ @Override public E higher(E e) { return ns.higher(e); }
+ @Override public E pollFirst() { throw new UnsupportedOperationException(); }
+ @Override public E pollLast() { throw new UnsupportedOperationException(); }
+ @Override
+ public NavigableSet<E> descendingSet() {
+ return new UnmodifiableNavigableSet<>(ns.descendingSet());
+ }
+
+ @Override
+ public Iterator<E> descendingIterator() {
+ return descendingSet().iterator();
+ }
+
+ @Override
+ public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+ return new UnmodifiableNavigableSet<>(ns.subSet(fromElement, fromInclusive, toElement, toInclusive));
+ }
+
+ @Override
+ public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+ return new UnmodifiableNavigableSet<>(ns.headSet(toElement, inclusive));
+ }
+
+ @Override
+ public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+ return new UnmodifiableNavigableSet<>(ns.tailSet(fromElement, inclusive));
+ }
+ }
+
+ /**
* Returns an unmodifiable view of the specified list. This method allows
* modules to provide users with "read-only" access to internal
* lists. Query operations on the returned list "read through" to the
* specified list, and attempts to modify the returned list, whether
* direct or via its iterator, result in an
*** 1668,1677 ****
--- 1732,1866 ----
public K firstKey() {return sm.firstKey();}
public K lastKey() {return sm.lastKey();}
}
+ /**
+ * Returns an unmodifiable view of the specified navigable map. This method
+ * allows modules to provide users with "read-only" access to internal
+ * navigable maps. Query operations on the returned navigable map "read
+ * through" to the specified navigable map. Attempts to modify the returned
+ * navigable map, whether direct, via its collection views, or via its
+ * <tt>subMap</tt>, <tt>headMap</tt>, or <tt>tailMap</tt> views, result in
+ * an <tt>UnsupportedOperationException</tt>.<p>
+ *
+ * The returned navigable map will be serializable if the specified
+ * navigable map is serializable.
+ *
+ * @param m the navigable map for which an unmodifiable view is to be
+ * returned
+ * @return an unmodifiable view of the specified navigable map
+ * @since 1.8
+ */
+ public static <K,V> SortedMap<K,V> unmodifiableNavigableMap(NavigableMap<K, ? extends V> m) {
+ return new UnmodifiableNavigableMap<>(m);
+ }
+
+ /**
+ * @serial include
+ */
+ static class UnmodifiableNavigableMap<K,V>
+ extends UnmodifiableSortedMap<K,V>
+ implements NavigableMap<K,V>, Serializable {
+ // private static final long serialVersionUID = -8806743815996713206L;
+
+ private final NavigableMap<K, ? extends V> nm;
+
+ UnmodifiableNavigableMap(NavigableMap<K, ? extends V> m) {super(m); nm = m;}
+
+ @Override
+ public Entry<K, V> lowerEntry(K key) {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.lowerEntry(key));
+ }
+
+ @Override
+ public K lowerKey(K key) {
+ return nm.lowerKey(key);
+ }
+
+ @Override
+ public Entry<K, V> floorEntry(K key) {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.floorEntry(key));
+ }
+
+ @Override
+ public K floorKey(K key) {
+ return nm.floorKey(key);
+ }
+
+ @Override
+ public Entry<K, V> ceilingEntry(K key) {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.ceilingEntry(key));
+ }
+
+ @Override
+ public K ceilingKey(K key) {
+ return nm.ceilingKey(key);
+ }
+
+ @Override
+ public Entry<K, V> higherEntry(K key) {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.higherEntry(key));
+ }
+
+ @Override
+ public K higherKey(K key) {
+ return nm.higherKey(key);
+ }
+
+ @Override
+ public Entry<K, V> firstEntry() {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.firstEntry());
+ }
+
+ @Override
+ public Entry<K, V> lastEntry() {
+ return new UnmodifiableEntrySet.UnmodifiableEntry(nm.lastEntry());
+ }
+
+ @Override
+ public Entry<K, V> pollFirstEntry() {
+ Entry<K,V> entry = (Entry<K,V>) nm.pollFirstEntry();
+ return (null == entry) ? null : new UnmodifiableEntrySet.UnmodifiableEntry(entry);
+ }
+
+ @Override
+ public Entry<K, V> pollLastEntry() {
+ Entry<K,V> entry = (Entry<K,V>) nm.pollLastEntry();
+ return (null == entry) ? null : new UnmodifiableEntrySet.UnmodifiableEntry(entry);
+ }
+
+ @Override
+ public NavigableMap<K, V> descendingMap() {
+ return (NavigableMap<K,V>) unmodifiableNavigableMap(nm.descendingMap());
+ }
+
+ @Override
+ public NavigableSet<K> navigableKeySet() {
+ return unmodifiableNavigableSet(nm.navigableKeySet());
+ }
+
+ @Override
+ public NavigableSet<K> descendingKeySet() {
+ return unmodifiableNavigableSet(nm.descendingKeySet());
+ }
+
+ @Override
+ public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+ return (NavigableMap<K,V>) unmodifiableNavigableMap(nm.subMap(fromKey, fromInclusive, toKey, toInclusive));
+ }
+
+ @Override
+ public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+ return (NavigableMap<K,V>) unmodifiableNavigableMap(nm.headMap(toKey, inclusive));
+ }
+
+ @Override
+ public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+ return (NavigableMap<K,V>) unmodifiableNavigableMap(nm.tailMap(fromKey, inclusive));
+ }
+ }
// Synch Wrappers
/**
* Returns a synchronized (thread-safe) collection backed by the specified
*** 1943,1952 ****
--- 2132,2245 ----
synchronized (mutex) {return ss.last();}
}
}
/**
+ * Returns a synchronized (thread-safe) sorted set backed by the specified
+ * navigable set. In order to guarantee serial access, it is critical that
+ * <strong>all</strong> access to the backing sorted set is accomplished
+ * through the returned navigable set (or its views).<p>
+ *
+ * It is imperative that the user manually synchronize on the returned
+ * navigable set when iterating over it or any of its <tt>subSet</tt>,
+ * <tt>headSet</tt>, or <tt>tailSet</tt> views.
+ * <pre>
+ * SortedSet s = Collections.synchronizedNavigableSet(new TreeSet());
+ * ...
+ * synchronized (s) {
+ * Iterator i = s.iterator(); // Must be in the synchronized block
+ * while (i.hasNext())
+ * foo(i.next());
+ * }
+ * </pre>
+ * or:
+ * <pre>
+ * SortedSet s = Collections.synchronizedNavigableSet(new TreeSet());
+ * SortedSet s2 = s.headSet(foo);
+ * ...
+ * synchronized (s) { // Note: s, not s2!!!
+ * Iterator i = s2.iterator(); // Must be in the synchronized block
+ * while (i.hasNext())
+ * foo(i.next());
+ * }
+ * </pre>
+ * Failure to follow this advice may result in non-deterministic behavior.
+ *
+ * <p>The returned navigable set will be serializable if the specified
+ * navigable set is serializable.
+ *
+ * @param s the navigable set to be "wrapped" in a synchronized navigable
+ * set
+ * @return a synchronized view of the specified navigable set
+ * @since 1.8
+ */
+ public static <T> NavigableSet<T> synchronizedNavigableSet(NavigableSet<T> s) {
+ return new SynchronizedNavigableSet<>(s);
+ }
+
+ /**
+ * @serial include
+ */
+ static class SynchronizedNavigableSet<E>
+ extends SynchronizedSortedSet<E>
+ implements NavigableSet<E>
+ {
+ //private static final long serialVersionUID = 8695801310862127406L;
+
+ private final NavigableSet<E> ns;
+
+ SynchronizedNavigableSet(NavigableSet<E> s) {
+ super(s);
+ ns = s;
+ }
+ SynchronizedNavigableSet(NavigableSet<E> s, Object mutex) {
+ super(s, mutex);
+ ns = s;
+ }
+ @Override public E lower(E e) { synchronized (mutex) {return ns.lower(e);} }
+ @Override public E floor(E e) { synchronized (mutex) {return ns.floor(e);} }
+ @Override public E ceiling(E e) { synchronized (mutex) {return ns.ceiling(e);} }
+ @Override public E higher(E e) { synchronized (mutex) {return ns.higher(e);} }
+ @Override public E pollFirst() { synchronized (mutex) {return ns.pollFirst();} }
+ @Override public E pollLast() { synchronized (mutex) {return ns.pollLast();} }
+ @Override
+ public NavigableSet<E> descendingSet() {
+ synchronized (mutex) {
+ return new SynchronizedNavigableSet<>(ns.descendingSet(), mutex);
+ }
+ }
+
+ @Override
+ public Iterator<E> descendingIterator() {
+ synchronized (mutex) {
+ return descendingSet().iterator();
+ }
+ }
+
+ @Override
+ public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+ synchronized (mutex) {
+ return new SynchronizedNavigableSet<>(ns.subSet(fromElement, fromInclusive, toElement, toInclusive), mutex);
+ }
+ }
+
+ @Override
+ public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+ synchronized (mutex) {
+ return new SynchronizedNavigableSet<>(ns.headSet(toElement, inclusive), mutex);
+ }
+ }
+
+ @Override
+ public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+ synchronized (mutex) {
+ return new SynchronizedNavigableSet<>(ns.tailSet(fromElement, inclusive));
+ }
+ }
+ }
+
+ /**
* Returns a synchronized (thread-safe) list backed by the specified
* list. In order to guarantee serial access, it is critical that
* <strong>all</strong> access to the backing list is accomplished
* through the returned list.<p>
*
*** 2382,2454 ****
public K lastKey() {
synchronized (mutex) {return sm.lastKey();}
}
}
- // Dynamically typesafe collection wrappers
-
/**
! * Returns a dynamically typesafe view of the specified collection.
! * Any attempt to insert an element of the wrong type will result in an
! * immediate {@link ClassCastException}. Assuming a collection
! * contains no incorrectly typed elements prior to the time a
! * dynamically typesafe view is generated, and that all subsequent
! * access to the collection takes place through the view, it is
! * <i>guaranteed</i> that the collection cannot contain an incorrectly
! * typed element.
! *
! * <p>The generics mechanism in the language provides compile-time
! * (static) type checking, but it is possible to defeat this mechanism
! * with unchecked casts. Usually this is not a problem, as the compiler
! * issues warnings on all such unchecked operations. There are, however,
! * times when static type checking alone is not sufficient. For example,
! * suppose a collection is passed to a third-party library and it is
! * imperative that the library code not corrupt the collection by
! * inserting an element of the wrong type.
! *
! * <p>Another use of dynamically typesafe views is debugging. Suppose a
! * program fails with a {@code ClassCastException}, indicating that an
! * incorrectly typed element was put into a parameterized collection.
! * Unfortunately, the exception can occur at any time after the erroneous
! * element is inserted, so it typically provides little or no information
! * as to the real source of the problem. If the problem is reproducible,
! * one can quickly determine its source by temporarily modifying the
! * program to wrap the collection with a dynamically typesafe view.
! * For example, this declaration:
! * <pre> {@code
! * Collection<String> c = new HashSet<String>();
! * }</pre>
! * may be replaced temporarily by this one:
! * <pre> {@code
! * Collection<String> c = Collections.checkedCollection(
! * new HashSet<String>(), String.class);
! * }</pre>
! * Running the program again will cause it to fail at the point where
! * an incorrectly typed element is inserted into the collection, clearly
! * identifying the source of the problem. Once the problem is fixed, the
! * modified declaration may be reverted back to the original.
! *
! * <p>The returned collection does <i>not</i> pass the hashCode and equals
! * operations through to the backing collection, but relies on
! * {@code Object}'s {@code equals} and {@code hashCode} methods. This
! * is necessary to preserve the contracts of these operations in the case
! * that the backing collection is a set or a list.
*
! * <p>The returned collection will be serializable if the specified
! * collection is serializable.
*
! * <p>Since {@code null} is considered to be a value of any reference
! * type, the returned collection permits insertion of null elements
! * whenever the backing collection does.
*
! * @param c the collection for which a dynamically typesafe view is to be
! * returned
! * @param type the type of element that {@code c} is permitted to hold
! * @return a dynamically typesafe view of the specified collection
! * @since 1.5
*/
! public static <E> Collection<E> checkedCollection(Collection<E> c,
Class<E> type) {
return new CheckedCollection<>(c, type);
}
@SuppressWarnings("unchecked")
--- 2675,2925 ----
public K lastKey() {
synchronized (mutex) {return sm.lastKey();}
}
}
/**
! * Returns a synchronized (thread-safe) navigable map backed by the
! * specified navigable map. In order to guarantee serial access, it is
! * critical that <strong>all</strong> access to the backing navigable map is
! * accomplished through the returned navigable map (or its views).<p>
*
! * It is imperative that the user manually synchronize on the returned
! * navigable map when iterating over any of its collection views, or the
! * collections views of any of its <tt>subMap</tt>, <tt>headMap</tt> or
! * <tt>tailMap</tt> views.
! * <pre>
! * SortedMap m = Collections.synchronizedNavigableMap(new TreeMap());
! * ...
! * Set s = m.keySet(); // Needn't be in synchronized block
! * ...
! * synchronized (m) { // Synchronizing on m, not s!
! * Iterator i = s.iterator(); // Must be in synchronized block
! * while (i.hasNext())
! * foo(i.next());
! * }
! * </pre>
! * or:
! * <pre>
! * SortedMap m = Collections.synchronizedNavigableMap(new TreeMap());
! * SortedMap m2 = m.subMap(foo, bar);
! * ...
! * Set s2 = m2.keySet(); // Needn't be in synchronized block
! * ...
! * synchronized (m) { // Synchronizing on m, not m2 or s2!
! * Iterator i = s.iterator(); // Must be in synchronized block
! * while (i.hasNext())
! * foo(i.next());
! * }
! * </pre>
! * Failure to follow this advice may result in non-deterministic behavior.
*
! * <p>The returned navigable map will be serializable if the specified
! * navigable map is serializable.
*
! * @param m the navigable map to be "wrapped" in a synchronized navigable
! * map
! * @return a synchronized view of the specified navigable map.
! * @since 1.8
*/
! public static <K,V> NavigableMap<K,V> synchronizedNavigableMap(NavigableMap<K,V> m) {
! return new SynchronizedNavigableMap<>(m);
! }
!
!
! /**
! * @serial include
! */
! static class SynchronizedNavigableMap<K,V>
! extends SynchronizedSortedMap<K,V>
! implements NavigableMap<K,V>
! {
! private static final long serialVersionUID = -8798146769416483793L;
!
! private final NavigableMap<K,V> nm;
!
! SynchronizedNavigableMap(NavigableMap<K,V> m) {
! super(m);
! nm = m;
! }
! SynchronizedNavigableMap(NavigableMap<K,V> m, Object mutex) {
! super(m, mutex);
! nm = m;
! }
!
! @Override
! public Entry<K, V> lowerEntry(K key) {
! synchronized (mutex) { return nm.lowerEntry(key); }
! }
!
! @Override
! public K lowerKey(K key) {
! synchronized (mutex) { return nm.lowerKey(key); }
! }
!
! @Override
! public Entry<K, V> floorEntry(K key) {
! synchronized (mutex) { return nm.floorEntry(key); }
! }
!
! @Override
! public K floorKey(K key) {
! synchronized (mutex) { return nm.floorKey(key); }
! }
!
! @Override
! public Entry<K, V> ceilingEntry(K key) {
! synchronized (mutex) { return nm.ceilingEntry(key); }
! }
!
! @Override
! public K ceilingKey(K key) {
! synchronized (mutex) { return nm.ceilingKey(key); }
! }
!
! @Override
! public Entry<K, V> higherEntry(K key) {
! synchronized (mutex) { return nm.higherEntry(key); }
! }
!
! @Override
! public K higherKey(K key) {
! synchronized (mutex) { return nm.higherKey(key); }
! }
!
! @Override
! public Entry<K, V> firstEntry() {
! synchronized (mutex) { return nm.firstEntry(); }
! }
!
! @Override
! public Entry<K, V> lastEntry() {
! synchronized (mutex) { return nm.lastEntry(); }
! }
!
! @Override
! public Entry<K, V> pollFirstEntry() {
! synchronized (mutex) {
! Entry<K,V> entry = (Entry<K,V>) nm.pollFirstEntry();
! return (null == entry) ? null : entry;
! }
! }
!
! @Override
! public Entry<K, V> pollLastEntry() {
! synchronized (mutex) {
! Entry<K,V> entry = (Entry<K,V>) nm.pollLastEntry();
! return (null == entry) ? null : entry;
! }
! }
!
! @Override
! public NavigableMap<K, V> descendingMap() {
! synchronized (mutex) {
! return (NavigableMap<K,V>) new SynchronizedNavigableMap(nm.descendingMap(), mutex);
! }
! }
!
! @Override
! public NavigableSet<K> navigableKeySet() {
! synchronized (mutex) {
! return new SynchronizedNavigableSet(nm.navigableKeySet(), mutex);
! }
! }
!
! @Override
! public NavigableSet<K> descendingKeySet() {
! synchronized (mutex) {
! return new SynchronizedNavigableSet(nm.descendingKeySet(), mutex);
! }
! }
!
! @Override
! public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
! synchronized (mutex) {
! return (NavigableMap<K,V>) new SynchronizedNavigableMap(nm.subMap(fromKey, fromInclusive, toKey, toInclusive), mutex);
! }
! }
!
! @Override
! public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
! synchronized (mutex) {
! return (NavigableMap<K,V>) new SynchronizedNavigableMap(nm.headMap(toKey, inclusive), mutex);
! }
! }
!
! @Override
! public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
! synchronized (mutex) {
! return (NavigableMap<K,V>) new SynchronizedNavigableMap(nm.tailMap(fromKey, inclusive), mutex);
! }
! }
! }
!
! // Dynamically typesafe collection wrappers
!
! /**
! * Returns a dynamically typesafe view of the specified collection.
! * Any attempt to insert an element of the wrong type will result in an
! * immediate {@link ClassCastException}. Assuming a collection
! * contains no incorrectly typed elements prior to the time a
! * dynamically typesafe view is generated, and that all subsequent
! * access to the collection takes place through the view, it is
! * <i>guaranteed</i> that the collection cannot contain an incorrectly
! * typed element.
! *
! * <p>The generics mechanism in the language provides compile-time
! * (static) type checking, but it is possible to defeat this mechanism
! * with unchecked casts. Usually this is not a problem, as the compiler
! * issues warnings on all such unchecked operations. There are, however,
! * times when static type checking alone is not sufficient. For example,
! * suppose a collection is passed to a third-party library and it is
! * imperative that the library code not corrupt the collection by
! * inserting an element of the wrong type.
! *
! * <p>Another use of dynamically typesafe views is debugging. Suppose a
! * program fails with a {@code ClassCastException}, indicating that an
! * incorrectly typed element was put into a parameterized collection.
! * Unfortunately, the exception can occur at any time after the erroneous
! * element is inserted, so it typically provides little or no information
! * as to the real source of the problem. If the problem is reproducible,
! * one can quickly determine its source by temporarily modifying the
! * program to wrap the collection with a dynamically typesafe view.
! * For example, this declaration:
! * <pre> {@code
! * Collection<String> c = new HashSet<String>();
! * }</pre>
! * may be replaced temporarily by this one:
! * <pre> {@code
! * Collection<String> c = Collections.checkedCollection(
! * new HashSet<String>(), String.class);
! * }</pre>
! * Running the program again will cause it to fail at the point where
! * an incorrectly typed element is inserted into the collection, clearly
! * identifying the source of the problem. Once the problem is fixed, the
! * modified declaration may be reverted back to the original.
! *
! * <p>The returned collection does <i>not</i> pass the hashCode and equals
! * operations through to the backing collection, but relies on
! * {@code Object}'s {@code equals} and {@code hashCode} methods. This
! * is necessary to preserve the contracts of these operations in the case
! * that the backing collection is a set or a list.
! *
! * <p>The returned collection will be serializable if the specified
! * collection is serializable.
! *
! * <p>Since {@code null} is considered to be a value of any reference
! * type, the returned collection permits insertion of null elements
! * whenever the backing collection does.
! *
! * @param c the collection for which a dynamically typesafe view is to be
! * returned
! * @param type the type of element that {@code c} is permitted to hold
! * @return a dynamically typesafe view of the specified collection
! * @since 1.5
! */
! public static <E> Collection<E> checkedCollection(Collection<E> c,
Class<E> type) {
return new CheckedCollection<>(c, type);
}
@SuppressWarnings("unchecked")
*** 2726,2735 ****
--- 3197,3308 ----
public SortedSet<E> tailSet(E fromElement) {
return checkedSortedSet(ss.tailSet(fromElement), type);
}
}
+ /**
+ * Returns a dynamically typesafe view of the specified navigable set.
+ * Any attempt to insert an element of the wrong type will result in an
+ * immediate {@link ClassCastException}. Assuming a navigable set
+ * contains no incorrectly typed elements prior to the time a
+ * dynamically typesafe view is generated, and that all subsequent
+ * access to the navigable set takes place through the view, it is
+ * <em>guaranteed</em> that the navigable set cannot contain an incorrectly
+ * typed element.
+ *
+ * <p>A discussion of the use of dynamically typesafe views may be
+ * found in the documentation for the {@link #checkedCollection
+ * checkedCollection} method.
+ *
+ * <p>The returned navigable set will be serializable if the specified
+ * navigable set is serializable.
+ *
+ * <p>Since {@code null} is considered to be a value of any reference
+ * type, the returned navigable set permits insertion of null elements
+ * whenever the backing sorted set does.
+ *
+ * @param s the navigable set for which a dynamically typesafe view is to be
+ * returned
+ * @param type the type of element that {@code s} is permitted to hold
+ * @return a dynamically typesafe view of the specified navigable set
+ * @since 1.8
+ */
+ public static <E> NavigableSet<E> checkedNavigableSet(NavigableSet<E> s,
+ Class<E> type) {
+ return new CheckedNavigableSet<>(s, type);
+ }
+
+ /**
+ * @serial include
+ */
+ static class CheckedNavigableSet<E> extends CheckedSortedSet<E>
+ implements NavigableSet<E>, Serializable
+ {
+ //private static final long serialVersionUID = 1599911165492914959L;
+ private final NavigableSet<E> ns;
+
+ CheckedNavigableSet(NavigableSet<E> s, Class<E> type) {
+ super(s, type);
+ ns = s;
+ }
+
+ @Override
+ public E lower(E e) {
+ return ns.lower(e);
+ }
+
+ @Override
+ public E floor(E e) {
+ return ns.floor(e);
+ }
+
+ @Override
+ public E ceiling(E e) {
+ return ns.ceiling(e);
+ }
+
+ @Override
+ public E higher(E e) {
+ return ns.higher(e);
+ }
+
+ @Override
+ public E pollFirst() {
+ return ns.pollFirst();
+ }
+
+ @Override
+ public E pollLast() {
+ return ns.pollLast();
+ }
+
+ @Override
+ public NavigableSet<E> descendingSet() {
+ return checkedNavigableSet(ns.descendingSet(), type);
+ }
+
+ @Override
+ public Iterator<E> descendingIterator() {
+ return checkedNavigableSet(ns.descendingSet(), type).iterator();
+ }
+
+ @Override
+ public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+ return checkedNavigableSet(ns.subSet(fromElement, fromInclusive, toElement, toInclusive), type);
+ }
+
+ @Override
+ public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+ return checkedNavigableSet(ns.headSet(toElement, inclusive), type);
+ }
+
+ @Override
+ public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+ return checkedNavigableSet(ns.tailSet(fromElement, inclusive), type);
+ }
+ }
+
/**
* Returns a dynamically typesafe view of the specified list.
* Any attempt to insert an element of the wrong type will result in
* an immediate {@link ClassCastException}. Assuming a list contains
* no incorrectly typed elements prior to the time a dynamically typesafe
*** 3323,3359 ****
public SortedMap<K,V> tailMap(K fromKey) {
return checkedSortedMap(sm.tailMap(fromKey), keyType, valueType);
}
}
- // Empty collections
-
/**
! * Returns an iterator that has no elements. More precisely,
! *
! * <ul compact>
! *
! * <li>{@link Iterator#hasNext hasNext} always returns {@code
! * false}.
*
! * <li>{@link Iterator#next next} always throws {@link
! * NoSuchElementException}.
*
! * <li>{@link Iterator#remove remove} always throws {@link
! * IllegalStateException}.
*
! * </ul>
*
! * <p>Implementations of this method are permitted, but not
! * required, to return the same object from multiple invocations.
*
! * @return an empty iterator
! * @since 1.7
*/
! @SuppressWarnings("unchecked")
! public static <T> Iterator<T> emptyIterator() {
! return (Iterator<T>) EmptyIterator.EMPTY_ITERATOR;
}
private static class EmptyIterator<E> implements Iterator<E> {
static final EmptyIterator<Object> EMPTY_ITERATOR
= new EmptyIterator<>();
--- 3896,4096 ----
public SortedMap<K,V> tailMap(K fromKey) {
return checkedSortedMap(sm.tailMap(fromKey), keyType, valueType);
}
}
/**
! * Returns a dynamically typesafe view of the specified navigable map.
! * Any attempt to insert a mapping whose key or value have the wrong
! * type will result in an immediate {@link ClassCastException}.
! * Similarly, any attempt to modify the value currently associated with
! * a key will result in an immediate {@link ClassCastException},
! * whether the modification is attempted directly through the map
! * itself, or through a {@link Map.Entry} instance obtained from the
! * map's {@link Map#entrySet() entry set} view.
*
! * <p>Assuming a map contains no incorrectly typed keys or values
! * prior to the time a dynamically typesafe view is generated, and
! * that all subsequent access to the map takes place through the view
! * (or one of its collection views), it is <em>guaranteed</em> that the
! * map cannot contain an incorrectly typed key or value.
*
! * <p>A discussion of the use of dynamically typesafe views may be
! * found in the documentation for the {@link #checkedCollection
! * checkedCollection} method.
*
! * <p>The returned map will be serializable if the specified map is
! * serializable.
*
! * <p>Since {@code null} is considered to be a value of any reference
! * type, the returned map permits insertion of null keys or values
! * whenever the backing map does.
*
! * @param m the map for which a dynamically typesafe view is to be
! * returned
! * @param keyType the type of key that {@code m} is permitted to hold
! * @param valueType the type of value that {@code m} is permitted to hold
! * @return a dynamically typesafe view of the specified map
! * @since 1.8
*/
! public static <K,V> NavigableMap<K,V> checkedNavigableMap(NavigableMap<K, V> m,
! Class<K> keyType,
! Class<V> valueType) {
! return new CheckedNavigableMap<>(m, keyType, valueType);
! }
!
! /**
! * @serial include
! */
! static class CheckedNavigableMap<K,V> extends CheckedSortedMap<K,V>
! implements NavigableMap<K,V>, Serializable
! {
! //private static final long serialVersionUID = 1599671320688067438L;
!
! private final NavigableMap<K, V> nm;
!
! CheckedNavigableMap(NavigableMap<K, V> m,
! Class<K> keyType, Class<V> valueType) {
! super(m, keyType, valueType);
! nm = m;
! }
!
! public Comparator<? super K> comparator() { return nm.comparator(); }
! public K firstKey() { return nm.firstKey(); }
! public K lastKey() { return nm.lastKey(); }
!
! public NavigableMap<K,V> subMap(K fromKey, K toKey) {
! return checkedNavigableMap((NavigableMap<K,V>)nm.subMap(fromKey, toKey),
! keyType, valueType);
! }
! public NavigableMap<K,V> headMap(K toKey) {
! return checkedNavigableMap((NavigableMap<K,V>)nm.headMap(toKey), keyType, valueType);
! }
! public NavigableMap<K,V> tailMap(K fromKey) {
! return checkedNavigableMap((NavigableMap<K,V>)nm.tailMap(fromKey), keyType, valueType);
! }
!
! @Override
! public Entry<K, V> lowerEntry(K key) {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.lowerEntry(key), valueType);
! }
!
! @Override
! public K lowerKey(K key) {
! return nm.lowerKey(key);
! }
!
! @Override
! public Entry<K, V> floorEntry(K key) {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.lowerEntry(key), valueType);
! }
!
! @Override
! public K floorKey(K key) {
! return nm.floorKey(key);
! }
!
! @Override
! public Entry<K, V> ceilingEntry(K key) {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.ceilingEntry(key), valueType);
! }
!
! @Override
! public K ceilingKey(K key) {
! return nm.ceilingKey(key);
! }
!
! @Override
! public Entry<K, V> higherEntry(K key) {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.higherEntry(key), valueType);
! }
!
! @Override
! public K higherKey(K key) {
! return nm.higherKey(key);
! }
!
! @Override
! public Entry<K, V> firstEntry() {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.firstEntry(), valueType);
! }
!
! @Override
! public Entry<K, V> lastEntry() {
! return new CheckedMap.CheckedEntrySet.CheckedEntry(nm.lastEntry(), valueType);
! }
!
! @Override
! public Entry<K, V> pollFirstEntry() {
! Entry<K,V> entry = nm.pollFirstEntry();
! return (null == entry) ? null : new CheckedMap.CheckedEntrySet.CheckedEntry(entry, valueType);
! }
!
! @Override
! public Entry<K, V> pollLastEntry() {
! Entry<K,V> entry = nm.pollLastEntry();
! return (null == entry) ? null : new CheckedMap.CheckedEntrySet.CheckedEntry(entry, valueType);
! }
!
! @Override
! public NavigableMap<K, V> descendingMap() {
! return checkedNavigableMap(nm.descendingMap(), keyType, valueType);
! }
!
! @Override
! public NavigableSet<K> navigableKeySet() {
! return checkedNavigableSet(nm.navigableKeySet(), keyType);
! }
!
! @Override
! public NavigableSet<K> descendingKeySet() {
! return checkedNavigableSet(nm.descendingKeySet(), keyType);
! }
!
! @Override
! public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
! return checkedNavigableMap(nm.subMap(fromKey, fromInclusive, toKey, toInclusive), keyType, valueType);
! }
!
! @Override
! public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
! return checkedNavigableMap(nm.headMap(toKey, inclusive), keyType, valueType);
! }
!
! @Override
! public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
! return checkedNavigableMap(nm.tailMap(fromKey, inclusive), keyType, valueType);
! }
! }
!
! // Empty collections
!
! /**
! * Returns an iterator that has no elements. More precisely,
! *
! * <ul compact>
! *
! * <li>{@link Iterator#hasNext hasNext} always returns {@code
! * false}.
! *
! * <li>{@link Iterator#next next} always throws {@link
! * NoSuchElementException}.
! *
! * <li>{@link Iterator#remove remove} always throws {@link
! * IllegalStateException}.
! *
! * </ul>
! *
! * <p>Implementations of this method are permitted, but not
! * required, to return the same object from multiple invocations.
! *
! * @return an empty iterator
! * @since 1.7
! */
! @SuppressWarnings("unchecked")
! public static <T> Iterator<T> emptyIterator() {
! return (Iterator<T>) EmptyIterator.EMPTY_ITERATOR;
}
private static class EmptyIterator<E> implements Iterator<E> {
static final EmptyIterator<Object> EMPTY_ITERATOR
= new EmptyIterator<>();
*** 3522,3631 ****
private Object readResolve() {
return EMPTY_SET;
}
}
/**
* Returns the empty sorted set (immutable). This set is serializable.
*
! * <p>This example illustrates the type-safe way to obtain an empty sorted
! * set:
! * <pre>
! * SortedSet<String> s = Collections.emptySortedSet();
! * </pre>
! * Implementation note: Implementations of this method need not
! * create a separate <tt>SortedSet</tt> object for each call.
*
* @since 1.8
*/
@SuppressWarnings("unchecked")
! public static final <E> SortedSet<E> emptySortedSet() {
! return (SortedSet<E>) new EmptySortedSet<>();
}
/**
* @serial include
*/
! private static class EmptySortedSet<E>
! extends AbstractSet<E>
! implements SortedSet<E>, Serializable
{
! private static final long serialVersionUID = 6316515401502265487L;
! public Iterator<E> iterator() { return emptyIterator(); }
! public int size() {return 0;}
! public boolean isEmpty() {return true;}
! public boolean contains(Object obj) {return false;}
! public boolean containsAll(Collection<?> c) { return c.isEmpty(); }
! public Object[] toArray() { return new Object[0]; }
! public <E> E[] toArray(E[] a) {
! if (a.length > 0)
! a[0] = null;
! return a;
}
// Preserves singleton property
private Object readResolve() {
! return new EmptySortedSet<>();
}
@Override
public Comparator<? super E> comparator() {
return null;
}
@Override
@SuppressWarnings("unchecked")
! public SortedSet<E> subSet(Object fromElement, Object toElement) {
! Objects.requireNonNull(fromElement);
! Objects.requireNonNull(toElement);
! if (!(fromElement instanceof Comparable) ||
! !(toElement instanceof Comparable))
! {
! throw new ClassCastException();
}
! if ((((Comparable)fromElement).compareTo(toElement) >= 0) ||
! (((Comparable)toElement).compareTo(fromElement) < 0))
! {
! throw new IllegalArgumentException();
}
! return emptySortedSet();
}
@Override
! public SortedSet<E> headSet(Object toElement) {
! Objects.requireNonNull(toElement);
! if (!(toElement instanceof Comparable)) {
! throw new ClassCastException();
}
! return emptySortedSet();
}
@Override
! public SortedSet<E> tailSet(Object fromElement) {
! Objects.requireNonNull(fromElement);
! if (!(fromElement instanceof Comparable)) {
! throw new ClassCastException();
}
! return emptySortedSet();
}
@Override
! public E first() {
! throw new NoSuchElementException();
}
@Override
! public E last() {
! throw new NoSuchElementException();
}
// Override default methods in Collection
@Override
public void forEach(Consumer<? super E> action) {
--- 4259,4422 ----
private Object readResolve() {
return EMPTY_SET;
}
}
+ private static final EmptyNavigableSet<?> EMPTY_NAVIGABLE_SET =
+ new EmptyNavigableSet<>();
+
/**
* Returns the empty sorted set (immutable). This set is serializable.
*
! * <p>This example illustrates the type-safe way to obtain an empty
! * sorted set:
! * <pre> {@code
! * SortedSet<String> s = Collections.emptySortedSet();
! * }</pre>
! *
! * @implNote Implementations of this method need not create a separate
! * {@code SortedSet} object for each call.
! *
! * @since 1.8
! */
! @SuppressWarnings("unchecked")
! public static <E> SortedSet<E> emptySortedSet() {
! return (SortedSet<E>) EMPTY_NAVIGABLE_SET;
! }
!
! /**
! * Returns the empty navigable set (immutable). This set is serializable.
! *
! * <p>This example illustrates the type-safe way to obtain an empty
! * navigable set:
! * <pre> {@code
! * NavigableSet<String> s = Collections.emptyNavigableSet();
! * }</pre>
! *
! * @implNote Implementations of this method need not
! * create a separate {@code NavigableSet} object for each call.
*
* @since 1.8
*/
@SuppressWarnings("unchecked")
! public static <E>NavigableSet<E> emptyNavigableSet() {
! return (NavigableSet<E>) EMPTY_NAVIGABLE_SET;
}
/**
* @serial include
*/
! private static class EmptyNavigableSet<E>
! extends EmptySet<E>
! implements NavigableSet<E>, Serializable
{
! // private static final long serialVersionUID = 6316515401502265487L;
! public boolean contains(Object obj) {
! Comparable<E> e = (Comparable<E>) obj;
! return obj != e;
}
// Preserves singleton property
private Object readResolve() {
! return Collections.emptyNavigableSet();
}
@Override
public Comparator<? super E> comparator() {
return null;
}
@Override
@SuppressWarnings("unchecked")
! public SortedSet<E> subSet(E fromElement, E toElement) {
! return subSet(fromElement, true, toElement, false);
! }
! @Override
! public SortedSet<E> headSet(E toElement) {
! return headSet(toElement, false);
}
! @Override
! public SortedSet<E> tailSet(E fromElement) {
! return tailSet(fromElement, true);
}
! @Override
! public E first() {
! throw new NoSuchElementException();
}
@Override
! public E last() {
! throw new NoSuchElementException();
! }
! @Override
! public E lower(E e) {
! Objects.requireNonNull(e);
! return null;
}
! @Override
! public E floor(E e) {
! Objects.requireNonNull(e);
! return null;
}
@Override
! public E ceiling(E e) {
! Objects.requireNonNull(e);
! return null;
! }
! @Override
! public E higher(E e) {
! Objects.requireNonNull(e);
! return null;
}
! @Override
! public E pollFirst() {
! return null;
}
@Override
! public E pollLast() {
! return null;
}
@Override
! public NavigableSet<E> descendingSet() {
! return new BoundedEmptyNavigableSet(null, true, null, true, true);
! }
!
! @Override
! public Iterator<E> descendingIterator() { return emptyIterator(); }
!
! @Override
! public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
! return new BoundedEmptyNavigableSet(
! (Comparable<E>) Objects.requireNonNull(fromElement), fromInclusive,
! (Comparable<E>) Objects.requireNonNull(toElement), toInclusive,
! false);
! }
!
! @Override
! public NavigableSet<E> headSet(E toElement, boolean inclusive) {
! return new BoundedEmptyNavigableSet(
! null, true,
! (Comparable<E>) Objects.requireNonNull(toElement), inclusive,
! false);
! }
!
! @Override
! public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
! return new BoundedEmptyNavigableSet(
! (Comparable<E>) Objects.requireNonNull(fromElement), inclusive,
! null, true, false);
}
// Override default methods in Collection
@Override
public void forEach(Consumer<? super E> action) {
*** 3736,3745 ****
--- 4527,4800 ----
private Object readResolve() {
return EMPTY_LIST;
}
}
+ private static class BoundedEmptyNavigableSet<E> extends EmptyNavigableSet<E>
+ implements Serializable {
+
+ final boolean descending;
+ final boolean lowerInclusive;
+ final boolean upperInclusive;
+ final Comparable<E> lowerBound;
+ final Comparable<E> upperBound;
+
+ public BoundedEmptyNavigableSet(
+ Comparable<E> fromElement, boolean lowerInclusive,
+ Comparable<E> toElement, boolean upperInclusive,
+ boolean descending) {
+ this.descending = descending;
+
+ if ((fromElement != null) && (toElement != null)) {
+ int fromCompared = Integer.signum(fromElement.compareTo((E)toElement));
+ int toCompared = Integer.signum(toElement.compareTo((E)fromElement));
+
+ if(fromCompared != -toCompared) {
+ throw new IllegalArgumentException("inconsistent compareTo");
+ }
+
+ if (!descending) {
+ if (fromCompared > 0) {
+ throw new IllegalArgumentException();
+ }
+ } else {
+ if (fromCompared < 0) {
+ throw new IllegalArgumentException();
+ }
+ }
+ }
+
+ this.lowerBound = fromElement;
+ this.lowerInclusive = lowerInclusive;
+ this.upperBound = toElement;
+ this.upperInclusive = upperInclusive;
+ }
+
+ @Override
+ public Comparator<E> comparator() {
+ return descending ? Collections.reverseOrder() : null;
+ }
+
+ public NavigableSet<E> descendingSet() {
+ return new BoundedEmptyNavigableSet(upperBound, upperInclusive, lowerBound, lowerInclusive, !descending);
+ }
+
+ @Override
+ public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+ return new BoundedEmptyNavigableSet(inBounds(fromElement), fromInclusive, inBounds(toElement), toInclusive, descending);
+ }
+
+ @Override
+ public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+ return new BoundedEmptyNavigableSet(lowerBound, lowerInclusive, inBounds(toElement), inclusive, descending);
+ }
+
+ @Override
+ public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+ return new BoundedEmptyNavigableSet(inBounds(fromElement), inclusive, upperBound, upperInclusive, descending);
+ }
+
+ private Comparable<E> inBounds(E element) {
+ if (!descending) {
+ if (null != lowerBound) {
+ if (lowerInclusive) {
+ if (lowerBound.compareTo(element) > 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (lowerBound.compareTo(element) >= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+
+ if (null != upperBound) {
+ if (upperInclusive) {
+ if (upperBound.compareTo(element) < 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (upperBound.compareTo(element) <= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+ } else {
+ if (null != lowerBound) {
+ if (lowerInclusive) {
+ if (lowerBound.compareTo(element) < 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (lowerBound.compareTo(element) <= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+
+ if (null != upperBound) {
+ if (upperInclusive) {
+ if (upperBound.compareTo(element) > 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (upperBound.compareTo(element) >= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+ }
+
+ return (Comparable<E>)Objects.requireNonNull(element);
+ }
+ }
+
+ private static class BoundedEmptyNavigableMap<K,V> extends EmptyNavigableMap<K,V>
+ implements Serializable {
+
+ final boolean descending;
+ final boolean lowerInclusive;
+ final boolean upperInclusive;
+ final Comparable<K> lowerBound;
+ final Comparable<K> upperBound;
+
+ public BoundedEmptyNavigableMap(
+ Comparable<K> fromElement, boolean lowerInclusive,
+ Comparable<K> toElement, boolean upperInclusive,
+ boolean descending) {
+ this.descending = descending;
+
+ if ((fromElement != null) && (toElement != null)) {
+ int fromCompared = Integer.signum(fromElement.compareTo((K)toElement));
+ int toCompared = Integer.signum(toElement.compareTo((K)fromElement));
+
+ if(fromCompared != -toCompared) {
+ throw new IllegalArgumentException("inconsistent compareTo");
+ }
+
+ if (!descending) {
+ if (fromCompared > 0) {
+ throw new IllegalArgumentException();
+ }
+ } else {
+ if (fromCompared < 0) {
+ throw new IllegalArgumentException();
+ }
+ }
+ }
+
+ this.lowerBound = fromElement;
+ this.lowerInclusive = lowerInclusive;
+ this.upperBound = toElement;
+ this.upperInclusive = upperInclusive;
+ }
+
+ @Override
+ public Comparator<? super K> comparator() {
+ return descending ? Collections.reverseOrder() : null;
+ }
+
+ @Override
+ public boolean containsKey(Object obj) {
+ Comparable<K> e = (Comparable<K>) obj;
+ return obj != e;
+ }
+
+ private Comparable<K> inBounds(K element) {
+ if (!descending) {
+ if (null != lowerBound) {
+ if (lowerInclusive) {
+ if (lowerBound.compareTo(element) > 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (lowerBound.compareTo(element) >= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+
+ if (null != upperBound) {
+ if (upperInclusive) {
+ if (upperBound.compareTo(element) < 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (upperBound.compareTo(element) <= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+ } else {
+ if (null != lowerBound) {
+ if (lowerInclusive) {
+ if (lowerBound.compareTo(element) < 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (lowerBound.compareTo(element) <= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+
+ if (null != upperBound) {
+ if (upperInclusive) {
+ if (upperBound.compareTo(element) > 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ } else {
+ if (upperBound.compareTo(element) >= 0) {
+ throw new IllegalArgumentException("out of bounds");
+ }
+ }
+ }
+ }
+
+ return (Comparable<K>)Objects.requireNonNull(element);
+ }
+
+ @Override
+ public NavigableMap<K, V> descendingMap() {
+ if (upperBound == null && lowerBound == null && descending) {
+ return Collections.emptyNavigableMap();
+ }
+ return new BoundedEmptyNavigableMap(upperBound, upperInclusive, lowerBound, lowerInclusive, !descending);
+ }
+
+ @Override
+ public NavigableSet<K> navigableKeySet() {
+ if (upperBound == null && lowerBound == null && !descending) {
+ return Collections.emptyNavigableSet();
+ }
+ return new BoundedEmptyNavigableSet(lowerBound, lowerInclusive, upperBound, upperInclusive, descending);
+ }
+
+ @Override
+ public NavigableSet<K> descendingKeySet() {
+ if (upperBound == null && lowerBound == null && descending) {
+ return Collections.emptyNavigableSet();
+ }
+ return new BoundedEmptyNavigableSet(upperBound, upperInclusive, lowerBound, lowerInclusive, !descending);
+ }
+
+ @Override
+ public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+ return new BoundedEmptyNavigableMap(inBounds(fromKey), fromInclusive, inBounds(toKey), toInclusive, descending);
+ }
+
+ @Override
+ public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+ return new BoundedEmptyNavigableMap(lowerBound, lowerInclusive, inBounds(toKey), inclusive, descending);
+ }
+
+ @Override
+ public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+ return new BoundedEmptyNavigableMap(inBounds(fromKey), inclusive, upperBound, upperInclusive, descending);
+ }
+ }
+
/**
* The empty map (immutable). This map is serializable.
*
* @see #emptyMap()
* @since 1.3
*** 3748,3758 ****
public static final Map EMPTY_MAP = new EmptyMap<>();
/**
* Returns the empty map (immutable). This map is serializable.
*
! * <p>This example illustrates the type-safe way to obtain an empty set:
* <pre>
* Map<String, Date> s = Collections.emptyMap();
* </pre>
* Implementation note: Implementations of this method need not
* create a separate <tt>Map</tt> object for each call. Using this
--- 4803,4813 ----
public static final Map EMPTY_MAP = new EmptyMap<>();
/**
* Returns the empty map (immutable). This map is serializable.
*
! * <p>This example illustrates the type-safe way to obtain an empty map:
* <pre>
* Map<String, Date> s = Collections.emptyMap();
* </pre>
* Implementation note: Implementations of this method need not
* create a separate <tt>Map</tt> object for each call. Using this
*** 3766,3775 ****
--- 4821,4870 ----
public static final <K,V> Map<K,V> emptyMap() {
return (Map<K,V>) EMPTY_MAP;
}
/**
+ * Returns the empty sorted map (immutable). This map is serializable.
+ *
+ * <p>This example illustrates the type-safe way to obtain an empty map:
+ * <pre> {@code
+ * SortedMap<String, Date> s = Collections.emptySortedMap();
+ * }</pre>
+ *
+ * @implNote Implementations of this method need not create a separate
+ * {@code SortedMap} object for each call.
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static final <K,V> SortedMap<K,V> emptySortedMap() {
+ return (SortedMap<K,V>) EMPTY_NAVIGABLE_MAP;
+ }
+
+ @SuppressWarnings("rawtypes")
+ private static final NavigableMap EMPTY_NAVIGABLE_MAP =
+ new EmptyNavigableMap();
+
+ /**
+ * Returns the empty navigable map (immutable). This map is serializable.
+ *
+ * <p>This example illustrates the type-safe way to obtain an empty map:
+ * <pre> {@code
+ * NavigableMap<String, Date> s = Collections.emptyNavigableMap();
+ * }</pre>
+ *
+ * @implNote Implementations of this method need not create a separate
+ * {@code NavigableMap} object for each call.
+ *
+ * @since 1.8
+ */
+ @SuppressWarnings("unchecked")
+ public static final <K,V> NavigableMap<K,V> emptyNavigableMap() {
+ return (NavigableMap<K,V>) EMPTY_NAVIGABLE_MAP;
+ }
+
+ /**
* @serial include
*/
private static class EmptyMap<K,V>
extends AbstractMap<K,V>
implements Serializable
*** 3856,3865 ****
--- 4951,5093 ----
private Object readResolve() {
return EMPTY_MAP;
}
}
+ private static class EmptyNavigableMap<K,V> extends EmptyMap<K,V>
+ implements NavigableMap<K,V>, Serializable {
+
+ EmptyNavigableMap() {
+
+ }
+
+ // Preserves singleton property
+ private Object readResolve() {
+ return Collections.emptyNavigableMap();
+ }
+
+ @Override
+ public Entry<K, V> lowerEntry(K key) {
+ return null;
+ }
+
+ @Override
+ public K lowerKey(K key) {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> floorEntry(K key) {
+ return null;
+ }
+
+ @Override
+ public K floorKey(K key) {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> ceilingEntry(K key) {
+ return null;
+ }
+
+ @Override
+ public K ceilingKey(K key) {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> higherEntry(K key) {
+ return null;
+ }
+
+ @Override
+ public K higherKey(K key) {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> firstEntry() {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> lastEntry() {
+ return null;
+ }
+
+ @Override
+ public Entry<K, V> pollFirstEntry() {
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public Entry<K, V> pollLastEntry() {
+ throw new UnsupportedOperationException();
+ }
+
+ @Override
+ public NavigableMap<K, V> descendingMap() {
+ return new BoundedEmptyNavigableMap<>(null, true, null, true, true);
+ }
+
+ @Override
+ public NavigableSet<K> navigableKeySet() {
+ return Collections.emptyNavigableSet();
+ }
+
+ @Override
+ public NavigableSet<K> descendingKeySet() {
+ return Collections.<K>emptyNavigableSet().descendingSet();
+ }
+
+ @Override
+ public NavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+ return new BoundedEmptyNavigableMap<>((Comparable<K>) fromKey, fromInclusive, (Comparable<K>) toKey, toInclusive, false);
+ }
+
+ @Override
+ public NavigableMap<K, V> headMap(K toKey, boolean inclusive) {
+ return new BoundedEmptyNavigableMap<>(null, false, (Comparable<K>) toKey, inclusive, false);
+ }
+
+ @Override
+ public NavigableMap<K, V> tailMap(K fromKey, boolean inclusive) {
+ return new BoundedEmptyNavigableMap<>((Comparable<K>) fromKey, inclusive, null, false, false);
+ }
+
+ @Override
+ public SortedMap<K, V> subMap(K fromKey, K toKey) {
+ return subMap(fromKey, true, toKey, false);
+ }
+
+ @Override
+ public SortedMap<K, V> headMap(K toKey) {
+ return headMap(toKey, false);
+ }
+
+ @Override
+ public SortedMap<K, V> tailMap(K fromKey) {
+ return tailMap(fromKey, true);
+ }
+
+ @Override
+ public Comparator<? super K> comparator() {
+ return null;
+ }
+
+ @Override
+ public K firstKey() {
+ return null;
+ }
+
+ @Override
+ public K lastKey() {
+ return null;
+ }
+ }
+
// Singleton collections
/**
* Returns an immutable set containing only the specified object.
* The returned set is serializable.