Collectors.ToMap Method

Definition

Namespace:

Java.Util.Streams

Assembly:

Mono.Android.dll

Overloads

ToMap(IFunction, IFunction)	Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.
ToMap(IFunction, IFunction, IBinaryOperator)	Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.
ToMap(IFunction, IFunction, IBinaryOperator, ISupplier)	Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

ToMap(IFunction, IFunction)

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

[Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;)Ljava/util/stream/Collector;", "", ApiSince=24)]
[Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U" })]
public static Java.Util.Streams.ICollector? ToMap (Java.Util.Functions.IFunction? keyMapper, Java.Util.Functions.IFunction? valueMapper);

[<Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;)Ljava/util/stream/Collector;", "", ApiSince=24)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U" })>]
static member ToMap : Java.Util.Functions.IFunction * Java.Util.Functions.IFunction -> Java.Util.Streams.ICollector

Parameters

keyMapper

IFunction

a mapping function to produce keys

valueMapper

IFunction

a mapping function to produce values

Returns

ICollector

a Collector which collects elements into a Map whose keys and values are the result of applying mapping functions to the input elements

Attributes

RegisterAttribute JavaTypeParametersAttribute

Remarks

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

If the mapped keys contain duplicates (according to Object#equals(Object)), an IllegalStateException is thrown when the collection operation is performed. If the mapped keys might have duplicates, use #toMap(Function, Function, BinaryOperator) instead.

There are no guarantees on the type, mutability, serializability, or thread-safety of the Map returned.

Java documentation for java.util.stream.Collectors.toMap(java.util.function.Function<? super T, ? extends K>, java.util.function.Function<? super T, ? extends U>).

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

ToMap(IFunction, IFunction, IBinaryOperator)

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

[Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;Ljava/util/function/BinaryOperator;)Ljava/util/stream/Collector;", "", ApiSince=24)]
[Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U" })]
public static Java.Util.Streams.ICollector? ToMap (Java.Util.Functions.IFunction? keyMapper, Java.Util.Functions.IFunction? valueMapper, Java.Util.Functions.IBinaryOperator? mergeFunction);

[<Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;Ljava/util/function/BinaryOperator;)Ljava/util/stream/Collector;", "", ApiSince=24)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U" })>]
static member ToMap : Java.Util.Functions.IFunction * Java.Util.Functions.IFunction * Java.Util.Functions.IBinaryOperator -> Java.Util.Streams.ICollector

Parameters

keyMapper

IFunction

a mapping function to produce keys

valueMapper

IFunction

a mapping function to produce values

mergeFunction

IBinaryOperator

a merge function, used to resolve collisions between values associated with the same key, as supplied to Map#merge(Object, Object, BiFunction)

Returns

ICollector

a Collector which collects elements into a Map whose keys are the result of applying a key mapping function to the input elements, and whose values are the result of applying a value mapping function to all input elements equal to the key and combining them using the merge function

Attributes

RegisterAttribute JavaTypeParametersAttribute

Remarks

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

If the mapped keys contain duplicates (according to Object#equals(Object)), the value mapping function is applied to each equal element, and the results are merged using the provided merging function.

There are no guarantees on the type, mutability, serializability, or thread-safety of the Map returned.

Java documentation for java.util.stream.Collectors.toMap(java.util.function.Function<? super T, ? extends K>, java.util.function.Function<? super T, ? extends U>, java.util.function.BinaryOperator<U>).

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

ToMap(IFunction, IFunction, IBinaryOperator, ISupplier)

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

[Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;Ljava/util/function/BinaryOperator;Ljava/util/function/Supplier;)Ljava/util/stream/Collector;", "", ApiSince=24)]
[Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U", "M extends java.util.Map<K, U>" })]
public static Java.Util.Streams.ICollector? ToMap (Java.Util.Functions.IFunction? keyMapper, Java.Util.Functions.IFunction? valueMapper, Java.Util.Functions.IBinaryOperator? mergeFunction, Java.Util.Functions.ISupplier? mapFactory);

[<Android.Runtime.Register("toMap", "(Ljava/util/function/Function;Ljava/util/function/Function;Ljava/util/function/BinaryOperator;Ljava/util/function/Supplier;)Ljava/util/stream/Collector;", "", ApiSince=24)>]
[<Java.Interop.JavaTypeParameters(new System.String[] { "T", "K", "U", "M extends java.util.Map<K, U>" })>]
static member ToMap : Java.Util.Functions.IFunction * Java.Util.Functions.IFunction * Java.Util.Functions.IBinaryOperator * Java.Util.Functions.ISupplier -> Java.Util.Streams.ICollector

Parameters

keyMapper

IFunction

a mapping function to produce keys

valueMapper

IFunction

a mapping function to produce values

mergeFunction

IBinaryOperator

a merge function, used to resolve collisions between values associated with the same key, as supplied to Map#merge(Object, Object, BiFunction)

mapFactory

ISupplier

a supplier providing a new empty Map into which the results will be inserted

Returns

ICollector

a Collector which collects elements into a Map whose keys are the result of applying a key mapping function to the input elements, and whose values are the result of applying a value mapping function to all input elements equal to the key and combining them using the merge function

Attributes

RegisterAttribute JavaTypeParametersAttribute

Remarks

Returns a Collector that accumulates elements into a Map whose keys and values are the result of applying the provided mapping functions to the input elements.

If the mapped keys contain duplicates (according to Object#equals(Object)), the value mapping function is applied to each equal element, and the results are merged using the provided merging function. The Map is created by a provided supplier function.

Java documentation for java.util.stream.Collectors.toMap(java.util.function.Function<? super T, ? extends K>, java.util.function.Function<? super T, ? extends U>, java.util.function.BinaryOperator<U>, java.util.function.Supplier<M>).

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.