Added in API level 24

Summary: Ctors | Methods | Inherited Methods

LongSummaryStatistics

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:

 LongSummaryStatistics stats = longStream.collect(LongSummaryStatistics::new,
                                                  LongSummaryStatistics::accept,
                                                  LongSummaryStatistics::combine);

LongSummaryStatistics can be used as a 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.

Summary

Public constructors
`LongSummaryStatistics()` Constructs an empty instance with zero count, zero sum, `Long.MAX_VALUE` min, `Long.MIN_VALUE` max and zero average.
`LongSummaryStatistics(long count, long min, long max, long sum)` Constructs a non-empty instance with the specified `count`, `min`, `max`, and `sum`.

Public methods
`void`	`accept(int value)` Records a new `int` value into the summary information.
`void`	`accept(long value)` Records a new `long` value into the summary information.
`void`	`combine(LongSummaryStatistics other)` Combines the state of another `LongSummaryStatistics` 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 long`	`getMax()` Returns the maximum value recorded, or `Long.MIN_VALUE` if no values have been recorded
`final long`	`getMin()` Returns the minimum value recorded, or `Long.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`	`toString()` Returns a non-empty string representation of this object suitable for debugging.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

From interface


        
          java.util.function.LongConsumer

`abstract void`	`accept(long value)` Performs this operation on the given argument.
`default LongConsumer`	`andThen(LongConsumer after)` Returns a composed `LongConsumer` that performs, in sequence, this operation followed by the `after` operation.

From interface


        
          java.util.function.IntConsumer

`abstract void`	`accept(int value)` Performs this operation on the given argument.
`default IntConsumer`	`andThen(IntConsumer after)` Returns a composed `IntConsumer` that performs, in sequence, this operation followed by the `after` operation.

Public constructors

LongSummaryStatistics

Added in API level 24

public LongSummaryStatistics ()

Constructs an empty instance with zero count, zero sum, Long.MAX_VALUE min, Long.MIN_VALUE max and zero average.

LongSummaryStatistics

Added in API level 33

public LongSummaryStatistics (long count, 
                long min, 
                long max, 
                long sum)

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 LongSummaryStatistics 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`	`long`: the minimum value
`max`	`long`: the maximum value
`sum`	`long`: the sum of all values

Throws
`IllegalArgumentException`	if the arguments are inconsistent

Public methods

accept

Added in API level 24

public void accept (int value)

Records a new int value into the summary information.

Parameters
`value`	`int`: the input value

accept

Added in API level 24

public void accept (long value)

Records a new long value into the summary information.

Parameters
`value`	`long`: the input value

combine

Added in API level 24

public void combine (LongSummaryStatistics other)

Combines the state of another LongSummaryStatistics into this one.

Parameters
`other`	`LongSummaryStatistics`: another `LongSummaryStatistics`

Throws
`NullPointerException`	if `other` is null

getAverage

Added in API level 24

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

Added in API level 24

public final long getCount ()

Returns the count of values recorded.

Returns
`long`	the count of values

getMax

Added in API level 24

public final 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

getMin

Added in API level 24

public final 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

getSum

Added in API level 24

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

Added in API level 24

public String 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`	a string representation of the object.