OpenJDK 1.22 · java.util.IntSummaryStatistics · APIdia, the JavaDoc alternative

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 ints with:

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

IntSummaryStatistics can be used as a reduction target for a 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.

Implementation Note

This implementation is not thread safe. However, it is safe to use Collectors.summarizingInt() 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.

Modifier and Type	Field and Description
private long	count
private int	max
private int	min
private long	sum

Constructor Summary

Access	Constructor and Description
public	IntSummaryStatistics() Constructs an empty instance with zero count, zero sum, `Integer.MAX_VALUE` min, `Integer.MIN_VALUE` max and zero average.
public	IntSummaryStatistics(long the count of values count, int the minimum value min, int the maximum value max, long the sum of all values sum) Constructs a non-empty instance with the specified `count`, `min`, `max`, and `sum`.

Method Summary

Modifier and Type	Method and Description
public void	accept(int the input value value) Implements java.util.function.IntConsumer.accept. Records a new value into the summary information
public void	combine(IntSummaryStatistics another `IntSummaryStatistics` other) Combines the state of another `IntSummaryStatistics` into this one.
public final double	Returns: the arithmetic mean of values, or zero if none getAverage() Returns the arithmetic mean of values recorded, or zero if no values have been recorded.
public final long	Returns: the count of values getCount() Returns the count of values recorded.
public final int	Returns: the maximum value, or `Integer.MIN_VALUE` if none getMax() Returns the maximum value recorded, or `Integer.MIN_VALUE` if no values have been recorded.
public final int	Returns: the minimum value, or `Integer.MAX_VALUE` if none getMin() Returns the minimum value recorded, or `Integer.MAX_VALUE` if no values have been recorded.
public final long	Returns: the sum of values, or zero if none getSum() Returns the sum of values recorded, or zero if no values have been recorded.
public String	toString() Overrides java.lang.Object.toString. Returns a non-empty string representation of this object suitable for debugging.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll wait wait wait

Field Detail

count	back to summary
private long count

max	back to summary
private int max

min	back to summary
private int min

sum	back to summary
private long sum

Constructor Detail

IntSummaryStatistics	back to summary
public IntSummaryStatistics() Constructs an empty instance with zero count, zero sum, `Integer.MAX_VALUE` min, `Integer.MIN_VALUE` max and zero average.

IntSummaryStatistics back to summary

IntSummaryStatistics	back to summary
public IntSummaryStatistics(long count, int min, int max, long sum) throws IllegalArgumentException Constructs a non-empty instance with the specified `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` API Note The enforcement of argument correctness means that the retrieved set of recorded values obtained from a `IntSummaryStatistics` 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. Parameters count:long the count of values min:int the minimum value max:int the maximum value sum:long the sum of all values Exceptions IllegalArgumentException: if the arguments are inconsistent Since 10

public IntSummaryStatistics(long count, int min, int max, long sum) throws IllegalArgumentException

Constructs a non-empty instance with the specified 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

API Note

The enforcement of argument correctness means that the retrieved set of recorded values obtained from a IntSummaryStatistics 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.

Parameters

count:long: the count of values
min:int: the minimum value
max:int: the maximum value
sum:long: the sum of all values

Exceptions

IllegalArgumentException:: if the arguments are inconsistent

Since

Method Detail

accept	back to summary
public void accept(int value) Implements java.util.function.IntConsumer.accept. Records a new value into the summary information Parameters value:int the input value Annotations @Override

back to summary

public void accept(int value)

Implements java.util.function.IntConsumer.accept.

Records a new value into the summary information

Parameters

value:int: the input value

Annotations

@Override

combine back to summary

combine	back to summary
public void combine(IntSummaryStatistics other) Combines the state of another `IntSummaryStatistics` into this one. Parameters other:IntSummaryStatistics another `IntSummaryStatistics` Exceptions NullPointerException: if `other` is null

public void combine(IntSummaryStatistics other)

Combines the state of another IntSummaryStatistics into this one.

Parameters

other:IntSummaryStatistics: another IntSummaryStatistics

Exceptions

NullPointerException:: if other is null

getAverage	back to summary
public final double getAverage() Returns the arithmetic mean of values recorded, or zero if no values have been recorded. Returns:double the arithmetic mean of values, or zero if none

getAverage

back to summary

public final double getAverage()

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

Returns:double: the arithmetic mean of values, or zero if none

getCount	back to summary
public final long getCount() Returns the count of values recorded. Returns:long the count of values

getCount

back to summary

public final long getCount()

Returns the count of values recorded.

Returns:long: the count of values

getMax back to summary

getMax	back to summary
public final int getMax() Returns the maximum value recorded, or `Integer.MIN_VALUE` if no values have been recorded. Returns:int the maximum value, or `Integer.MIN_VALUE` if none

public final int getMax()

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

Returns:int: the maximum value, or Integer.MIN_VALUE if none

getMin back to summary

getMin	back to summary
public final int getMin() Returns the minimum value recorded, or `Integer.MAX_VALUE` if no values have been recorded. Returns:int the minimum value, or `Integer.MAX_VALUE` if none

public final int getMin()

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

Returns:int: the minimum value, or Integer.MAX_VALUE if none

getSum	back to summary
public final long getSum() Returns the sum of values recorded, or zero if no values have been recorded. Returns:long the sum of values, or zero if none

getSum

back to summary

public final long getSum()

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

Returns:long: the sum of values, or zero if none

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions. Returns:String Doc from java.lang.Object.toString. a string representation of the object Annotations @Override

toString

back to summary

public String toString()

Overrides java.lang.Object.toString.

Returns a non-empty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.

Returns:String

Doc from java.lang.Object.toString.

a string representation of the object

Annotations

@Override

public Class IntSummaryStatistics

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail