Class IntSummaryStatistics
 java.lang.Object

 java.util.IntSummaryStatistics
 All Implemented Interfaces:
IntConsumer
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) 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 ofStream.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.
 Since:
 1.8
Constructor Summary
Constructor  Description 

IntSummaryStatistics()  Constructs an empty instance with zero count, zero sum, 
IntSummaryStatistics(long count,
int min,
int max,
long sum)  Constructs a nonempty instance with the specified 
Method Summary
Modifier and Type  Method  Description 

void  accept(int value)  Records a new value into the summary information 
void  combine(IntSummaryStatistics other)  Combines the state of another 
double  getAverage()  Returns the arithmetic mean of values recorded, or zero if no values have been recorded. 
long  getCount()  Returns the count of values recorded. 
int  getMax()  Returns the maximum value recorded, or 
int  getMin()  Returns the minimum value recorded, or 
long  getSum()  Returns the sum of values recorded, or zero if no values have been recorded. 
String  toString()  Returns a nonempty string representation of this object suitable for debugging. 
Methods declared in class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods declared in interface java.util.function.IntConsumer
andThen
Constructor Detail
IntSummaryStatistics
public IntSummaryStatistics()
Constructs an empty instance with zero count, zero sum, Integer.MAX_VALUE
min, Integer.MIN_VALUE
max and zero average.
IntSummaryStatistics
public IntSummaryStatistics(long count, int min, int max, long sum) throws IllegalArgumentException
Constructs a nonempty 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, andsum
= 0.  Parameters:

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

IllegalArgumentException
 if the arguments are inconsistent  Since:
 10
Method Detail
accept
public void accept(int value)
Records a new value into the summary information
 Specified by:

accept
in interfaceIntConsumer
 Parameters:

value
 the input value
combine
public void combine(IntSummaryStatistics other)
Combines the state of another IntSummaryStatistics
into this one.
 Parameters:

other
 anotherIntSummaryStatistics
 Throws:

NullPointerException
 ifother
is null
getCount
public final long getCount()
Returns the count of values recorded.
 Returns:
 the count of values
getSum
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
getMin
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
getMax
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
getAverage
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
toString
public String toString()
Returns a nonempty string representation of this object suitable for debugging. The exact presentation format is unspecified and may vary between implementations and versions.