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Collector.Characteristics

public static final enum Collector.Characteristics
extends Enum<Collector.Characteristics>

java.lang.Object
   ↳ java.lang.Enum<java.util.stream.Collector.Characteristics>
     ↳ java.util.stream.Collector.Characteristics


Characteristics indicating properties of a Collector, which can be used to optimize reduction implementations.

Summary

Enum values

Collector.Characteristics  CONCURRENT

Indicates that this collector is concurrent, meaning that the result container can support the accumulator function being called concurrently with the same result container from multiple threads. 

Collector.Characteristics  IDENTITY_FINISH

Indicates that the finisher function is the identity function and can be elided. 

Collector.Characteristics  UNORDERED

Indicates that the collection operation does not commit to preserving the encounter order of input elements. 

Public methods

static Collector.Characteristics valueOf(String name)
static final Characteristics[] values()

Inherited methods

Enum values

CONCURRENT

added in API level 24
public static final Collector.Characteristics CONCURRENT

Indicates that this collector is concurrent, meaning that the result container can support the accumulator function being called concurrently with the same result container from multiple threads.

If a CONCURRENT collector is not also UNORDERED, then it should only be evaluated concurrently if applied to an unordered data source.

IDENTITY_FINISH

added in API level 24
public static final Collector.Characteristics IDENTITY_FINISH

Indicates that the finisher function is the identity function and can be elided. If set, it must be the case that an unchecked cast from A to R will succeed.

UNORDERED

added in API level 24
public static final Collector.Characteristics UNORDERED

Indicates that the collection operation does not commit to preserving the encounter order of input elements. (This might be true if the result container has no intrinsic order, such as a Set.)

Public methods

valueOf

added in API level 24
public static Collector.Characteristics valueOf (String name)

Parameters
name String

Returns
Collector.Characteristics

values

added in API level 24
public static final Characteristics[] values ()

Returns
Characteristics[]