Package | Description |
---|---|
java.util |
Contains the collections framework, legacy collection classes, event model,
date and time facilities, internationalization, and miscellaneous utility
classes (a string tokenizer, a random-number generator, and a bit array).
|
java.util.concurrent |
Utility classes commonly useful in concurrent programming.
|
java.util.stream |
Classes to support functional-style operations on streams of elements, such
as map-reduce transformations on collections.
|
Modifier and Type | Method and Description |
---|---|
static <T> Comparator<T> |
Comparator.comparingLong(ToLongFunction<? super T> keyExtractor)
Accepts a function that extracts a
long sort key from a type
T , and returns a Comparator<T> that compares by that
sort key. |
default Comparator<T> |
Comparator.thenComparingLong(ToLongFunction<? super T> keyExtractor)
Returns a lexicographic-order comparator with a function that
extracts a
long sort key. |
Modifier and Type | Method and Description |
---|---|
long |
ConcurrentHashMap.reduceEntriesToLong(long parallelismThreshold,
ToLongFunction<Map.Entry<K,V>> transformer,
long basis,
LongBinaryOperator reducer)
Returns the result of accumulating the given transformation
of all entries using the given reducer to combine values,
and the given basis as an identity value.
|
long |
ConcurrentHashMap.reduceKeysToLong(long parallelismThreshold,
ToLongFunction<? super K> transformer,
long basis,
LongBinaryOperator reducer)
Returns the result of accumulating the given transformation
of all keys using the given reducer to combine values, and
the given basis as an identity value.
|
long |
ConcurrentHashMap.reduceValuesToLong(long parallelismThreshold,
ToLongFunction<? super V> transformer,
long basis,
LongBinaryOperator reducer)
Returns the result of accumulating the given transformation
of all values using the given reducer to combine values,
and the given basis as an identity value.
|
Modifier and Type | Method and Description |
---|---|
static <T> Collector<T,?,Double> |
Collectors.averagingLong(ToLongFunction<? super T> mapper)
Returns a
Collector that produces the arithmetic mean of a long-valued
function applied to the input elements. |
LongStream |
Stream.mapToLong(ToLongFunction<? super T> mapper)
Returns a
LongStream consisting of the results of applying the
given function to the elements of this stream. |
static <T> Collector<T,?,LongSummaryStatistics> |
Collectors.summarizingLong(ToLongFunction<? super T> mapper)
Returns a
Collector which applies an long -producing
mapping function to each input element, and returns summary statistics
for the resulting values. |
static <T> Collector<T,?,Long> |
Collectors.summingLong(ToLongFunction<? super T> mapper)
Returns a
Collector that produces the sum of a long-valued
function applied to the input elements. |
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