public
class
LongSummaryStatistics
extends Object
implements
LongConsumer,
IntConsumer
| java.lang.Object | |
| ↳ | java.util.LongSummaryStatistics |
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:
Developers
LongSummaryStatistics stats = longStream.collect(LongSummaryStatistics::new,
LongSummaryStatistics::accept,
LongSummaryStatistics::combine);
LongSummaryStatistics can be used as a
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.
Public constructors | |
|---|---|
LongSummaryStatistics()
Construct an empty instance with zero count, zero sum,
|
|
Public methods | |
|---|---|
void
|
accept(int value)
Records a new |
void
|
accept(long value)
Records a new |
void
|
combine(LongSummaryStatistics other)
Combines the state of another |
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 |
final
long
|
getMin()
Returns the minimum value recorded, or |
final
long
|
getSum()
Returns the sum of values recorded, or zero if no values have been recorded. |
String
|
toString()
Returns a string representation of the object. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
From
interface
java.util.function.LongConsumer
| |
From
interface
java.util.function.IntConsumer
| |
LongSummaryStatistics ()
Construct an empty instance with zero count, zero sum,
Long.MAX_VALUE min, Long.MIN_VALUE max and zero
average.
void accept (int value)
Records a new int value into the summary information.
| Parameters | |
|---|---|
value |
int:
the input value
|
void accept (long value)
Records a new long value into the summary information.
| Parameters | |
|---|---|
value |
long:
the input value
|
void combine (LongSummaryStatistics other)
Combines the state of another LongSummaryStatistics into this
one.
| Parameters | |
|---|---|
other |
LongSummaryStatistics:
another LongSummaryStatistics |
| Throws | |
|---|---|
NullPointerException |
if other is null
|
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 |
long getCount ()
Returns the count of values recorded.
| Returns | |
|---|---|
long |
the count of values |
long getMax ()
Returns the maximum value recorded, or Long.MIN_VALUE if no
values have been recorded
| Returns | |
|---|---|
long |
the maximum value, or Long.MIN_VALUE if none
|
long getMin ()
Returns the minimum value recorded, or Long.MAX_VALUE if no
values have been recorded.
| Returns | |
|---|---|
long |
the minimum value, or Long.MAX_VALUE if none
|
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 |
String toString ()
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())
| Returns | |
|---|---|
String |
a string representation of the object. |