IntSummaryStatistics

public class IntSummaryStatistics extends Object
implements 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) {@linkplain java.util.stream streams}. For example, you can compute summary statistics on a stream of ints with:

 IntSummaryStatistics stats = intStream.collect(IntSummaryStatistics::new,
                                                IntSummaryStatistics::accept,
                                                IntSummaryStatistics::combine);
 

IntSummaryStatistics can be used as a {@linkplain java.util.stream.Stream#collect(Collector) reduction} target for a {@linkplain java.util.stream.Stream stream}. For example:

 IntSummaryStatistics stats = people.stream()
                                    .collect(Collectors.summarizingInt(Person::getDependents));
This computes, in a single pass, the count of people, as well as the minimum, maximum, sum, and average of their number of dependents.

Public Constructor Summary

IntSummaryStatistics()
Construct an empty instance with zero count, zero sum, Integer.MAX_VALUE min, Integer.MIN_VALUE max and zero average.

Public Method Summary

void
accept(int value)
Records a new value into the summary information
void
combine(IntSummaryStatistics other)
Combines the state of another IntSummaryStatistics 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 int
getMax()
Returns the maximum value recorded, or Integer.MIN_VALUE if no values have been recorded.
final int
getMin()
Returns the minimum value recorded, or Integer.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

Inherited Method Summary

Public Constructors

public IntSummaryStatistics ()

Construct an empty instance with zero count, zero sum, Integer.MAX_VALUE min, Integer.MIN_VALUE max and zero average.

Public Methods

public void accept (int value)

Records a new value into the summary information

Parameters
value the input value

public void combine (IntSummaryStatistics other)

Combines the state of another IntSummaryStatistics into this one.

Parameters
other another IntSummaryStatistics
Throws
NullPointerException if other is null

public final double getAverage ()

Returns the arithmetic mean of values recorded, or zero if no values have been recorded.

Returns
  • the arithmetic mean of values, or zero if none

public final long getCount ()

Returns the count of values recorded.

Returns
  • the count of values

public final int getMax ()

Returns the maximum value recorded, or Integer.MIN_VALUE if no values have been recorded.

Returns
  • the maximum value, or Integer.MIN_VALUE if none

public final int getMin ()

Returns the minimum value recorded, or Integer.MAX_VALUE if no values have been recorded.

Returns
  • the minimum value, or Integer.MAX_VALUE if none

public final long getSum ()

Returns the sum of values recorded, or zero if no values have been recorded.

Returns
  • the sum of values, or zero if none

public String toString ()