IntConsumer
, LongConsumer
public class LongSummaryStatistics extends Object implements LongConsumer, IntConsumer
This class is designed to work with (though does not require) streams. For example, you can compute summary statistics on a stream of longs with:
LongSummaryStatistics stats = longStream.collect(LongSummaryStatistics::new,
LongSummaryStatistics::accept,
LongSummaryStatistics::combine);
LongSummaryStatistics
can be used as a reduction target for a stream. For example:
LongSummaryStatistics stats = people.stream()
.collect(Collectors.summarizingLong(Person::getAge));
This computes, in a single pass, the count of people, as well as the minimum, maximum, sum, and average of their ages.Collectors.summarizingLong()
on a parallel stream, because the parallel implementation of Stream.collect()
provides the necessary partitioning, isolation, and merging of results for safe and efficient parallel execution. This implementation does not check for overflow of the count or the sum.
Constructor | Description |
---|---|
LongSummaryStatistics() |
Constructs an empty instance with zero count, zero sum, Long.MAX_VALUE min, Long.MIN_VALUE max and zero average. |
LongSummaryStatistics |
Constructs a non-empty instance with the specified count , min , max , and sum . |
Modifier and Type | Method | Description |
---|---|---|
void |
accept |
Records a new int value into the summary information. |
void |
accept |
Records a new long value into the summary information. |
void |
combine |
Combines the state of another LongSummaryStatistics into this one. |
final double |
getAverage() |
Returns the arithmetic mean of values recorded, or zero if no values have been recorded. |
final long |
getCount() |
Returns the count of values recorded. |
final long |
getMax() |
Returns the maximum value recorded, or Long.MIN_VALUE if no values have been recorded |
final long |
getMin() |
Returns the minimum value recorded, or Long.MAX_VALUE if no values have been recorded. |
final long |
getSum() |
Returns the sum of values recorded, or zero if no values have been recorded. |
String |
toString() |
Returns a non-empty string representation of this object suitable for debugging. |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
andThen
andThen
public LongSummaryStatistics()
Long.MAX_VALUE
min, Long.MIN_VALUE
max and zero average.public LongSummaryStatistics(long count, long min, long max, long sum) throws IllegalArgumentException
count
, min
, max
, and sum
. If count
is zero then the remaining arguments are ignored and an empty instance is constructed.
If the arguments are inconsistent then an IllegalArgumentException
is thrown. The necessary consistent argument conditions are:
count >= 0
min <= max
LongSummaryStatistics
source instance may not be a legal set of arguments for this constructor due to arithmetic overflow of the source's recorded count of values. The consistent argument conditions are not sufficient to prevent the creation of an internally inconsistent instance. An example of such a state would be an instance with: count
= 2, min
= 1, max
= 2, and sum
= 0.count
- the count of valuesmin
- the minimum valuemax
- the maximum valuesum
- the sum of all valuesIllegalArgumentException
- if the arguments are inconsistentpublic void accept(int value)
int
value into the summary information.accept
in interface IntConsumer
value
- the input valuepublic void accept(long value)
long
value into the summary information.accept
in interface LongConsumer
value
- the input valuepublic void combine(LongSummaryStatistics other)
LongSummaryStatistics
into this one.other
- another LongSummaryStatistics
NullPointerException
- if other
is nullpublic final long getCount()
public final long getSum()
public final long getMin()
Long.MAX_VALUE
if no values have been recorded.Long.MAX_VALUE
if nonepublic final long getMax()
Long.MIN_VALUE
if no values have been recordedLong.MIN_VALUE
if nonepublic final double getAverage()
public String toString()
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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
Various third party code in OpenJDK is licensed under different licenses (see Debian package).
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/util/LongSummaryStatistics.html