public class LongSummaryStatistics extends Object implements LongConsumer, IntConsumer
A state object for collecting statistics such as count, min, max, sum, and average.
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 Stream.collect(Collector) 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.toLongStatistics() 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 sum.
public LongSummaryStatistics()
Construct an empty instance with zero count, zero sum, Long.MAX_VALUE min, Long.MIN_VALUE max and zero average.
public void accept(int value)
Records a new int value into the summary information.
accept in interface IntConsumer
value - the input valuepublic void accept(long value)
Records a new long value into the summary information.
accept in interface LongConsumer
value - the input valuepublic void combine(LongSummaryStatistics other)
Combines the state of another LongSummaryStatistics into this one.
other - another LongSummaryStatistics
NullPointerException - if other is nullpublic final long getCount()
Returns the count of values recorded.
public final long getSum()
Returns the sum of values recorded, or zero if no values have been recorded.
public final long getMin()
Returns the minimum value recorded, or Long.MAX_VALUE if no values have been recorded.
Long.MAX_VALUE if nonepublic final long getMax()
Returns the maximum value recorded, or Long.MIN_VALUE if no values have been recorded
Long.MIN_VALUE if nonepublic final double getAverage()
Returns the arithmetic mean of values recorded, or zero if no values have been recorded.
public String toString()
Description copied from class: Object
Returns a string representation of the object. In general, the toString method returns a string that "textually represents" this object. The result should be a concise but informative representation that is easy for a person to read. It is recommended that all subclasses override this method.
The toString method for class Object returns a string consisting of the name of the class of which the object is an instance, the at-sign character `@', and the unsigned hexadecimal representation of the hash code of the object. In other words, this method returns a string equal to the value of:
getClass().getName() + '@' + Integer.toHexString(hashCode())
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Documentation extracted from Debian's OpenJDK Development Kit package.
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