NavigableMap (Java SE 10 & JDK 10 ) (original) (raw)
Nested Class Summary
* ### Nested classes/interfaces declared in interface java.util.[Map](../../java/util/Map.html "interface in java.util") `[Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/Map.Entry.html "type parameter in Map.Entry"),[V](../../java/util/Map.Entry.html "type parameter in Map.Entry")>`Method Summary
All Methods Instance Methods Abstract Methods
Modifier and Type Method Description Map.Entry<K,V> ceilingEntry(K key) Returns a key-value mapping associated with the least key greater than or equal to the given key, or null if there is no such key. K ceilingKey(K key) Returns the least key greater than or equal to the given key, or null if there is no such key. NavigableSet<K> descendingKeySet() Returns a reverse order NavigableSet view of the keys contained in this map. NavigableMap<K,V> descendingMap() Returns a reverse order view of the mappings contained in this map. Map.Entry<K,V> firstEntry() Returns a key-value mapping associated with the least key in this map, or null if the map is empty. Map.Entry<K,V> floorEntry(K key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, or null if there is no such key. K floorKey(K key) Returns the greatest key less than or equal to the given key, or null if there is no such key. SortedMap<K,V> headMap(K toKey) Returns a view of the portion of this map whose keys are strictly less than toKey. NavigableMap<K,V> headMap(K toKey, boolean inclusive) Returns a view of the portion of this map whose keys are less than (or equal to, if inclusive is true) toKey. Map.Entry<K,V> higherEntry(K key) Returns a key-value mapping associated with the least key strictly greater than the given key, or null if there is no such key. K higherKey(K key) Returns the least key strictly greater than the given key, ornull if there is no such key. Map.Entry<K,V> lastEntry() Returns a key-value mapping associated with the greatest key in this map, or null if the map is empty. Map.Entry<K,V> lowerEntry(K key) Returns a key-value mapping associated with the greatest key strictly less than the given key, or null if there is no such key. K lowerKey(K key) Returns the greatest key strictly less than the given key, ornull if there is no such key. NavigableSet<K> navigableKeySet() Returns a NavigableSet view of the keys contained in this map. Map.Entry<K,V> pollFirstEntry() Removes and returns a key-value mapping associated with the least key in this map, or null if the map is empty. Map.Entry<K,V> pollLastEntry() Removes and returns a key-value mapping associated with the greatest key in this map, or null if the map is empty. NavigableMap<K,V> subMap(K fromKey, boolean fromInclusive,K toKey, boolean toInclusive) Returns a view of the portion of this map whose keys range fromfromKey to toKey. SortedMap<K,V> subMap(K fromKey,K toKey) Returns a view of the portion of this map whose keys range fromfromKey, inclusive, to toKey, exclusive. SortedMap<K,V> tailMap(K fromKey) Returns a view of the portion of this map whose keys are greater than or equal to fromKey. NavigableMap<K,V> tailMap(K fromKey, boolean inclusive) Returns a view of the portion of this map whose keys are greater than (or equal to, if inclusive is true) fromKey. * ### Methods declared in interface java.util.[Map](../../java/util/Map.html "interface in java.util") `[clear](../../java/util/Map.html#clear%28%29), [compute](../../java/util/Map.html#compute%28K,java.util.function.BiFunction%29), [computeIfAbsent](../../java/util/Map.html#computeIfAbsent%28K,java.util.function.Function%29), [computeIfPresent](../../java/util/Map.html#computeIfPresent%28K,java.util.function.BiFunction%29), [containsKey](../../java/util/Map.html#containsKey%28java.lang.Object%29), [containsValue](../../java/util/Map.html#containsValue%28java.lang.Object%29), [equals](../../java/util/Map.html#equals%28java.lang.Object%29), [forEach](../../java/util/Map.html#forEach%28java.util.function.BiConsumer%29), [get](../../java/util/Map.html#get%28java.lang.Object%29), [getOrDefault](../../java/util/Map.html#getOrDefault%28java.lang.Object,V%29), [hashCode](../../java/util/Map.html#hashCode%28%29), [isEmpty](../../java/util/Map.html#isEmpty%28%29), [merge](../../java/util/Map.html#merge%28K,V,java.util.function.BiFunction%29), [put](../../java/util/Map.html#put%28K,V%29), [putAll](../../java/util/Map.html#putAll%28java.util.Map%29), [putIfAbsent](../../java/util/Map.html#putIfAbsent%28K,V%29), [remove](../../java/util/Map.html#remove%28java.lang.Object%29), [remove](../../java/util/Map.html#remove%28java.lang.Object,java.lang.Object%29), [replace](../../java/util/Map.html#replace%28K,V%29), [replace](../../java/util/Map.html#replace%28K,V,V%29), [replaceAll](../../java/util/Map.html#replaceAll%28java.util.function.BiFunction%29), [size](../../java/util/Map.html#size%28%29)` * ### Methods declared in interface java.util.[SortedMap](../../java/util/SortedMap.html "interface in java.util") `[comparator](../../java/util/SortedMap.html#comparator%28%29), [entrySet](../../java/util/SortedMap.html#entrySet%28%29), [firstKey](../../java/util/SortedMap.html#firstKey%28%29), [keySet](../../java/util/SortedMap.html#keySet%28%29), [lastKey](../../java/util/SortedMap.html#lastKey%28%29), [values](../../java/util/SortedMap.html#values%28%29)`Method Detail
* #### lowerEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> lowerEntry([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns a key-value mapping associated with the greatest key strictly less than the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: an entry with the greatest key less than `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### lowerKey [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") lowerKey([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns the greatest key strictly less than the given key, or`null` if there is no such key. Parameters: `key` \- the key Returns: the greatest key less than `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### floorEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> floorEntry([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns a key-value mapping associated with the greatest key less than or equal to the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: an entry with the greatest key less than or equal to`key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### floorKey [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") floorKey([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns the greatest key less than or equal to the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: the greatest key less than or equal to `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### ceilingEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> ceilingEntry([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns a key-value mapping associated with the least key greater than or equal to the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: an entry with the least key greater than or equal to`key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### ceilingKey [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") ceilingKey([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns the least key greater than or equal to the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: the least key greater than or equal to `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### higherEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> higherEntry([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns a key-value mapping associated with the least key strictly greater than the given key, or `null` if there is no such key. Parameters: `key` \- the key Returns: an entry with the least key greater than `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### higherKey [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") higherKey([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") key) Returns the least key strictly greater than the given key, or`null` if there is no such key. Parameters: `key` \- the key Returns: the least key greater than `key`, or `null` if there is no such key Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if the specified key cannot be compared with the keys currently in the map `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if the specified key is null and this map does not permit null keys * #### firstEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> firstEntry() Returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. Returns: an entry with the least key, or `null` if this map is empty * #### lastEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> lastEntry() Returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. Returns: an entry with the greatest key, or `null` if this map is empty * #### pollFirstEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> pollFirstEntry() Removes and returns a key-value mapping associated with the least key in this map, or `null` if the map is empty. Returns: the removed first entry of this map, or `null` if this map is empty * #### pollLastEntry [Map.Entry](../../java/util/Map.Entry.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> pollLastEntry() Removes and returns a key-value mapping associated with the greatest key in this map, or `null` if the map is empty. Returns: the removed last entry of this map, or `null` if this map is empty * #### descendingMap [NavigableMap](../../java/util/NavigableMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> descendingMap() Returns a reverse order view of the mappings contained in this map. The descending map is backed by this map, so changes to the map are reflected in the descending map, and vice-versa. If either map is modified while an iteration over a collection view of either map is in progress (except through the iterator's own `remove` operation), the results of the iteration are undefined. The returned map has an ordering equivalent to[Collections.reverseOrder](../../java/util/Collections.html#reverseOrder%28java.util.Comparator%29)`(comparator())`. The expression `m.descendingMap().descendingMap()` returns a view of `m` essentially equivalent to `m`. Returns: a reverse order view of this map * #### navigableKeySet [NavigableSet](../../java/util/NavigableSet.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap")> navigableKeySet() Returns a [NavigableSet](../../java/util/NavigableSet.html "interface in java.util") view of the keys contained in this map. The set's iterator returns the keys in ascending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own ` remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`,`removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations. Returns: a navigable set view of the keys in this map * #### descendingKeySet [NavigableSet](../../java/util/NavigableSet.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap")> descendingKeySet() Returns a reverse order [NavigableSet](../../java/util/NavigableSet.html "interface in java.util") view of the keys contained in this map. The set's iterator returns the keys in descending order. The set is backed by the map, so changes to the map are reflected in the set, and vice-versa. If the map is modified while an iteration over the set is in progress (except through the iterator's own ` remove` operation), the results of the iteration are undefined. The set supports element removal, which removes the corresponding mapping from the map, via the `Iterator.remove`, `Set.remove`,`removeAll`, `retainAll`, and `clear` operations. It does not support the `add` or `addAll` operations. Returns: a reverse order navigable set view of the keys in this map * #### subMap [NavigableMap](../../java/util/NavigableMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> subMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") fromKey, boolean fromInclusive, [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") toKey, boolean toInclusive) Returns a view of the portion of this map whose keys range from`fromKey` to `toKey`. If `fromKey` and`toKey` are equal, the returned map is empty unless`fromInclusive` and `toInclusive` are both true. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside of its range, or to construct a submap either of whose endpoints lie outside its range. Parameters: `fromKey` \- low endpoint of the keys in the returned map `fromInclusive` \- `true` if the low endpoint is to be included in the returned view `toKey` \- high endpoint of the keys in the returned map `toInclusive` \- `true` if the high endpoint is to be included in the returned view Returns: a view of the portion of this map whose keys range from`fromKey` to `toKey` Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `fromKey` and `toKey` cannot be compared to one another using this map's comparator (or, if the map has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if `fromKey` or `toKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `fromKey` or `toKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `fromKey` is greater than`toKey`; or if this map itself has a restricted range, and `fromKey` or `toKey` lies outside the bounds of the range * #### headMap [NavigableMap](../../java/util/NavigableMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> headMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") toKey, boolean inclusive) Returns a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Parameters: `toKey` \- high endpoint of the keys in the returned map `inclusive` \- `true` if the high endpoint is to be included in the returned view Returns: a view of the portion of this map whose keys are less than (or equal to, if `inclusive` is true) `toKey` Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `toKey` is not compatible with this map's comparator (or, if the map has no comparator, if `toKey` does not implement [Comparable](../../java/lang/Comparable.html "interface in java.lang")). Implementations may, but are not required to, throw this exception if `toKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `toKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if this map itself has a restricted range, and `toKey` lies outside the bounds of the range * #### tailMap [NavigableMap](../../java/util/NavigableMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> tailMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") fromKey, boolean inclusive) Returns a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Parameters: `fromKey` \- low endpoint of the keys in the returned map `inclusive` \- `true` if the low endpoint is to be included in the returned view Returns: a view of the portion of this map whose keys are greater than (or equal to, if `inclusive` is true) `fromKey` Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `fromKey` is not compatible with this map's comparator (or, if the map has no comparator, if `fromKey` does not implement [Comparable](../../java/lang/Comparable.html "interface in java.lang")). Implementations may, but are not required to, throw this exception if `fromKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `fromKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if this map itself has a restricted range, and `fromKey` lies outside the bounds of the range * #### subMap [SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> subMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") fromKey, [K](../../java/util/NavigableMap.html "type parameter in NavigableMap") toKey) Returns a view of the portion of this map whose keys range from`fromKey`, inclusive, to `toKey`, exclusive. (If`fromKey` and `toKey` are equal, the returned map is empty.) The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `subMap(fromKey, true, toKey, false)`. Specified by: `[subMap](../../java/util/SortedMap.html#subMap%28K,K%29)` in interface `[SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")>` Parameters: `fromKey` \- low endpoint (inclusive) of the keys in the returned map `toKey` \- high endpoint (exclusive) of the keys in the returned map Returns: a view of the portion of this map whose keys range from`fromKey`, inclusive, to `toKey`, exclusive Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `fromKey` and `toKey` cannot be compared to one another using this map's comparator (or, if the map has no comparator, using natural ordering). Implementations may, but are not required to, throw this exception if `fromKey` or `toKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `fromKey` or `toKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if `fromKey` is greater than`toKey`; or if this map itself has a restricted range, and `fromKey` or `toKey` lies outside the bounds of the range * #### headMap [SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> headMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") toKey) Returns a view of the portion of this map whose keys are strictly less than `toKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `headMap(toKey, false)`. Specified by: `[headMap](../../java/util/SortedMap.html#headMap%28K%29)` in interface `[SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")>` Parameters: `toKey` \- high endpoint (exclusive) of the keys in the returned map Returns: a view of the portion of this map whose keys are strictly less than `toKey` Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `toKey` is not compatible with this map's comparator (or, if the map has no comparator, if `toKey` does not implement [Comparable](../../java/lang/Comparable.html "interface in java.lang")). Implementations may, but are not required to, throw this exception if `toKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `toKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if this map itself has a restricted range, and `toKey` lies outside the bounds of the range * #### tailMap [SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")> tailMap([K](../../java/util/NavigableMap.html "type parameter in NavigableMap") fromKey) Returns a view of the portion of this map whose keys are greater than or equal to `fromKey`. The returned map is backed by this map, so changes in the returned map are reflected in this map, and vice-versa. The returned map supports all optional map operations that this map supports. The returned map will throw an `IllegalArgumentException` on an attempt to insert a key outside its range. Equivalent to `tailMap(fromKey, true)`. Specified by: `[tailMap](../../java/util/SortedMap.html#tailMap%28K%29)` in interface `[SortedMap](../../java/util/SortedMap.html "interface in java.util")<[K](../../java/util/NavigableMap.html "type parameter in NavigableMap"),[V](../../java/util/NavigableMap.html "type parameter in NavigableMap")>` Parameters: `fromKey` \- low endpoint (inclusive) of the keys in the returned map Returns: a view of the portion of this map whose keys are greater than or equal to `fromKey` Throws: `[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang")` \- if `fromKey` is not compatible with this map's comparator (or, if the map has no comparator, if `fromKey` does not implement [Comparable](../../java/lang/Comparable.html "interface in java.lang")). Implementations may, but are not required to, throw this exception if `fromKey` cannot be compared to keys currently in the map. `[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang")` \- if `fromKey` is null and this map does not permit null keys `[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang")` \- if this map itself has a restricted range, and `fromKey` lies outside the bounds of the range