Uses of Interface
java.util.function.Function
Packages that use Function
Package
Description
Provides classes that are fundamental to the design of the Java
programming language.
HTTP Client and WebSocket APIs
Provides the classes and interfaces for the security framework.
Contains the collections framework, some internationalization support classes,
a service loader, properties, random number generation, string parsing
and scanning classes, base64 encoding and decoding, a bit array, and
several miscellaneous utility classes.
Utility classes commonly useful in concurrent programming.
Functional interfaces provide target types for lambda expressions
and method references.
Provides the classes and interfaces of
the Java 2 platform's core logging facilities.
Classes for matching character sequences against patterns specified
by regular expressions.
Classes to support functional-style operations on streams of elements, such
as map-reduce transformations on collections.
Provides interfaces for creating tools, such as a Read-Eval-Print Loop (REPL),
which interactively evaluate "snippets" of Java programming language code.
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Uses of Function in java.lang
Modifier and TypeMethodDescriptionModuleLayer.defineModules(Configuration cf, Function<String, ClassLoader> clf) Creates a new module layer, with this layer as its parent, by defining the modules in the givenConfigurationto the Java virtual machine.static ModuleLayer.ControllerModuleLayer.defineModules(Configuration cf, List<ModuleLayer> parentLayers, Function<String, ClassLoader> clf) Creates a new module layer by defining the modules in the givenConfigurationto the Java virtual machine.static <T> StringTemplate.ProcessorPREVIEW<T, RuntimeException> StringTemplate.Processor.of(Function<? super StringTemplatePREVIEW, ? extends T> process) This factory method can be used to create aStringTemplate.ProcessorPREVIEW containing aStringTemplate.Processor.process(java.lang.StringTemplate)PREVIEW method derived from a lambda expression.<R> RThis method allows the application of a function tothisstring.<T> TStackWalker.walk(Function<? super Stream<StackWalker.StackFrame>, ? extends T> function) Applies the given function to the stream ofStackFrames for the current thread, traversing from the top frame of the stack, which is the method calling thiswalkmethod. -
Uses of Function in java.net.http
Methods in java.net.http with parameters of type FunctionModifier and TypeMethodDescriptionvoidHttpResponse.PushPromiseHandler.applyPushPromise(HttpRequest initiatingRequest, HttpRequest pushPromiseRequest, Function<HttpResponse.BodyHandler<T>, CompletableFuture<HttpResponse<T>>> acceptor) Notification of an incoming push promise.static <S extends Flow.Subscriber<? super String>,T>
HttpResponse.BodyHandler<T> HttpResponse.BodyHandlers.fromLineSubscriber(S subscriber, Function<? super S, ? extends T> finisher, String lineSeparator) Returns a response body handler that returns aBodySubscriber<T>obtained fromBodySubscribers.fromLineSubscriber(subscriber, finisher, charset, lineSeparator), with the givensubscriber,finisherfunction, and line separator.static <S extends Flow.Subscriber<? super String>,T>
HttpResponse.BodySubscriber<T> HttpResponse.BodySubscribers.fromLineSubscriber(S subscriber, Function<? super S, ? extends T> finisher, Charset charset, String lineSeparator) Returns a body subscriber that forwards all response body to the givenFlow.Subscriber, line by line.static <S extends Flow.Subscriber<? super List<ByteBuffer>>,T>
HttpResponse.BodyHandler<T> HttpResponse.BodyHandlers.fromSubscriber(S subscriber, Function<? super S, ? extends T> finisher) Returns a response body handler that returns aBodySubscriber<T>obtained fromHttpResponse.BodySubscribers.fromSubscriber(Subscriber, Function), with the givensubscriberandfinisherfunction.static <S extends Flow.Subscriber<? super List<ByteBuffer>>,T>
HttpResponse.BodySubscriber<T> HttpResponse.BodySubscribers.fromSubscriber(S subscriber, Function<? super S, ? extends T> finisher) Returns a body subscriber that forwards all response body to the givenFlow.Subscriber.static <T,U> HttpResponse.BodySubscriber <U> HttpResponse.BodySubscribers.mapping(HttpResponse.BodySubscriber<T> upstream, Function<? super T, ? extends U> mapper) Returns aBodySubscriberwhose response body value is that of the result of applying the given function to the body object of the givenupstreamBodySubscriber.static <T> HttpResponse.PushPromiseHandler<T> HttpResponse.PushPromiseHandler.of(Function<HttpRequest, HttpResponse.BodyHandler<T>> pushPromiseHandler, ConcurrentMap<HttpRequest, CompletableFuture<HttpResponse<T>>> pushPromisesMap) Returns a push promise handler that accumulates push promises, and their responses, into the given map. -
Uses of Function in java.security
Methods in java.security with parameters of type FunctionModifier and TypeMethodDescriptionProvider.computeIfAbsent(Object key, Function<? super Object, ? extends Object> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull. -
Uses of Function in java.util
Modifier and TypeMethodDescriptionstatic <T,U extends Comparable<? super U>>
Comparator<T> Accepts a function that extracts aComparablesort key from a typeT, and returns aComparator<T>that compares by that sort key.static <T,U> Comparator <T> Comparator.comparing(Function<? super T, ? extends U> keyExtractor, Comparator<? super U> keyComparator) Accepts a function that extracts a sort key from a typeT, and returns aComparator<T>that compares by that sort key using the specifiedComparator.HashMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull.Hashtable.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull.default VMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull.TreeMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull.<U> Optional<U> If a value is present, returns the result of applying the givenOptional-bearing mapping function to the value, otherwise returns an emptyOptional.<U> Optional<U> If a value is present, returns anOptionaldescribing (as if byOptional.ofNullable(T)) the result of applying the given mapping function to the value, otherwise returns an emptyOptional.default <U extends Comparable<? super U>>
Comparator<T> Comparator.thenComparing(Function<? super T, ? extends U> keyExtractor) Returns a lexicographic-order comparator with a function that extracts aComparablesort key.default <U> Comparator<T> Comparator.thenComparing(Function<? super T, ? extends U> keyExtractor, Comparator<? super U> keyComparator) Returns a lexicographic-order comparator with a function that extracts a key to be compared with the givenComparator. -
Uses of Function in java.util.concurrent
Methods in java.util.concurrent with parameters of type FunctionModifier and TypeMethodDescription<U> CompletableFuture<U> CompletableFuture.applyToEither(CompletionStage<? extends T> other, Function<? super T, U> fn) <U> CompletionStage<U> CompletionStage.applyToEither(CompletionStage<? extends T> other, Function<? super T, U> fn) Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed with the corresponding result as argument to the supplied function.<U> CompletableFuture<U> CompletableFuture.applyToEitherAsync(CompletionStage<? extends T> other, Function<? super T, U> fn) <U> CompletableFuture<U> CompletableFuture.applyToEitherAsync(CompletionStage<? extends T> other, Function<? super T, U> fn, Executor executor) <U> CompletionStage<U> CompletionStage.applyToEitherAsync(CompletionStage<? extends T> other, Function<? super T, U> fn) Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using this stage's default asynchronous execution facility, with the corresponding result as argument to the supplied function.<U> CompletionStage<U> CompletionStage.applyToEitherAsync(CompletionStage<? extends T> other, Function<? super T, U> fn, Executor executor) Returns a new CompletionStage that, when either this or the other given stage complete normally, is executed using the supplied executor, with the corresponding result as argument to the supplied function.ConcurrentHashMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map unlessnull.default VConcurrentMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value (or is mapped tonull), attempts to compute its value using the given mapping function and enters it into this map unlessnull.ConcurrentSkipListMap.computeIfAbsent(K key, Function<? super K, ? extends V> mappingFunction) If the specified key is not already associated with a value, attempts to compute its value using the given mapping function and enters it into this map unlessnull.CompletableFuture.exceptionally(Function<Throwable, ? extends T> fn) CompletionStage.exceptionally(Function<Throwable, ? extends T> fn) Returns a new CompletionStage that, when this stage completes exceptionally, is executed with this stage's exception as the argument to the supplied function.default CompletionStage<T> CompletionStage.exceptionallyAsync(Function<Throwable, ? extends T> fn) Returns a new CompletionStage that, when this stage completes exceptionally, is executed with this stage's exception as the argument to the supplied function, using this stage's default asynchronous execution facility.default CompletionStage<T> CompletionStage.exceptionallyAsync(Function<Throwable, ? extends T> fn, Executor executor) Returns a new CompletionStage that, when this stage completes exceptionally, is executed with this stage's exception as the argument to the supplied function, using the supplied Executor.default CompletionStage<T> CompletionStage.exceptionallyCompose(Function<Throwable, ? extends CompletionStage<T>> fn) Returns a new CompletionStage that, when this stage completes exceptionally, is composed using the results of the supplied function applied to this stage's exception.default CompletionStage<T> CompletionStage.exceptionallyComposeAsync(Function<Throwable, ? extends CompletionStage<T>> fn) Returns a new CompletionStage that, when this stage completes exceptionally, is composed using the results of the supplied function applied to this stage's exception, using this stage's default asynchronous execution facility.default CompletionStage<T> CompletionStage.exceptionallyComposeAsync(Function<Throwable, ? extends CompletionStage<T>> fn, Executor executor) Returns a new CompletionStage that, when this stage completes exceptionally, is composed using the results of the supplied function applied to this stage's exception, using the supplied Executor.<U> voidConcurrentHashMap.forEachEntry(long parallelismThreshold, Function<Map.Entry<K, V>, ? extends U> transformer, Consumer<? super U> action) Performs the given action for each non-null transformation of each entry.<U> voidConcurrentHashMap.forEachKey(long parallelismThreshold, Function<? super K, ? extends U> transformer, Consumer<? super U> action) Performs the given action for each non-null transformation of each key.<U> voidConcurrentHashMap.forEachValue(long parallelismThreshold, Function<? super V, ? extends U> transformer, Consumer<? super U> action) Performs the given action for each non-null transformation of each value.<U> UConcurrentHashMap.reduceEntries(long parallelismThreshold, Function<Map.Entry<K, V>, ? extends U> transformer, BiFunction<? super U, ? super U, ? extends U> reducer) Returns the result of accumulating the given transformation of all entries using the given reducer to combine values, or null if none.<U> UConcurrentHashMap.reduceKeys(long parallelismThreshold, Function<? super K, ? extends U> transformer, BiFunction<? super U, ? super U, ? extends U> reducer) Returns the result of accumulating the given transformation of all keys using the given reducer to combine values, or null if none.<U> UConcurrentHashMap.reduceValues(long parallelismThreshold, Function<? super V, ? extends U> transformer, BiFunction<? super U, ? super U, ? extends U> reducer) Returns the result of accumulating the given transformation of all values using the given reducer to combine values, or null if none.Returns the result of the first subtask that completed successfullyPREVIEW, otherwise throws an exception produced by the given exception supplying function.<U> UConcurrentHashMap.searchEntries(long parallelismThreshold, Function<Map.Entry<K, V>, ? extends U> searchFunction) Returns a non-null result from applying the given search function on each entry, or null if none.<U> UConcurrentHashMap.searchKeys(long parallelismThreshold, Function<? super K, ? extends U> searchFunction) Returns a non-null result from applying the given search function on each key, or null if none.<U> UConcurrentHashMap.searchValues(long parallelismThreshold, Function<? super V, ? extends U> searchFunction) Returns a non-null result from applying the given search function on each value, or null if none.<U> CompletableFuture<U> <U> CompletionStage<U> Returns a new CompletionStage that, when this stage completes normally, is executed with this stage's result as the argument to the supplied function.<U> CompletableFuture<U> CompletableFuture.thenApplyAsync(Function<? super T, ? extends U> fn) <U> CompletableFuture<U> CompletableFuture.thenApplyAsync(Function<? super T, ? extends U> fn, Executor executor) <U> CompletionStage<U> CompletionStage.thenApplyAsync(Function<? super T, ? extends U> fn) Returns a new CompletionStage that, when this stage completes normally, is executed using this stage's default asynchronous execution facility, with this stage's result as the argument to the supplied function.<U> CompletionStage<U> CompletionStage.thenApplyAsync(Function<? super T, ? extends U> fn, Executor executor) Returns a new CompletionStage that, when this stage completes normally, is executed using the supplied Executor, with this stage's result as the argument to the supplied function.<U> CompletableFuture<U> CompletableFuture.thenCompose(Function<? super T, ? extends CompletionStage<U>> fn) <U> CompletionStage<U> CompletionStage.thenCompose(Function<? super T, ? extends CompletionStage<U>> fn) Returns a new CompletionStage that is completed with the same value as the CompletionStage returned by the given function.<U> CompletableFuture<U> CompletableFuture.thenComposeAsync(Function<? super T, ? extends CompletionStage<U>> fn) <U> CompletableFuture<U> CompletableFuture.thenComposeAsync(Function<? super T, ? extends CompletionStage<U>> fn, Executor executor) <U> CompletionStage<U> CompletionStage.thenComposeAsync(Function<? super T, ? extends CompletionStage<U>> fn) Returns a new CompletionStage that is completed with the same value as the CompletionStage returned by the given function, executed using this stage's default asynchronous execution facility.<U> CompletionStage<U> CompletionStage.thenComposeAsync(Function<? super T, ? extends CompletionStage<U>> fn, Executor executor) Returns a new CompletionStage that is completed with the same value as the CompletionStage returned by the given function, executed using the supplied Executor.<X extends Throwable>
voidStructuredTaskScope.ShutdownOnFailure.throwIfFailed(Function<Throwable, ? extends X> esf) -
Uses of Function in java.util.function
Subinterfaces of Function in java.util.functionModifier and TypeInterfaceDescriptioninterfaceRepresents an operation on a single operand that produces a result of the same type as its operand.Methods in java.util.function that return FunctionModifier and TypeMethodDescriptionReturns a composed function that first applies this function to its input, and then applies theafterfunction to the result.Returns a composed function that first applies thebeforefunction to its input, and then applies this function to the result.static <T> Function<T, T> Function.identity()Returns a function that always returns its input argument.Methods in java.util.function with parameters of type FunctionModifier and TypeMethodDescriptiondefault <V> BiFunction<T, U, V> Returns a composed function that first applies this function to its input, and then applies theafterfunction to the result.Returns a composed function that first applies this function to its input, and then applies theafterfunction to the result.Returns a composed function that first applies thebeforefunction to its input, and then applies this function to the result. -
Uses of Function in java.util.logging
Methods in java.util.logging with parameters of type FunctionModifier and TypeMethodDescriptionvoidLogManager.updateConfiguration(InputStream ins, Function<String, BiFunction<String, String, String>> mapper) Updates the logging configuration.voidLogManager.updateConfiguration(Function<String, BiFunction<String, String, String>> mapper) Updates the logging configuration. -
Uses of Function in java.util.regex
Methods in java.util.regex with parameters of type FunctionModifier and TypeMethodDescriptionMatcher.replaceAll(Function<MatchResult, String> replacer) Replaces every subsequence of the input sequence that matches the pattern with the result of applying the given replacer function to the match result of this matcher corresponding to that subsequence.Matcher.replaceFirst(Function<MatchResult, String> replacer) Replaces the first subsequence of the input sequence that matches the pattern with the result of applying the given replacer function to the match result of this matcher corresponding to that subsequence. -
Uses of Function in java.util.stream
Methods in java.util.stream that return FunctionModifier and TypeMethodDescriptionCollector.finisher()Perform the final transformation from the intermediate accumulation typeAto the final result typeR.Methods in java.util.stream with parameters of type FunctionModifier and TypeMethodDescriptionstatic <T,A, R, RR>
Collector<T, A, RR> Collectors.collectingAndThen(Collector<T, A, R> downstream, Function<R, RR> finisher) Adapts aCollectorto perform an additional finishing transformation.<R> Stream<R> Returns a stream consisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.static <T,U, A, R>
Collector<T, ?, R> Collectors.flatMapping(Function<? super T, ? extends Stream<? extends U>> mapper, Collector<? super U, A, R> downstream) Adapts aCollectoraccepting elements of typeUto one accepting elements of typeTby applying a flat mapping function to each input element before accumulation.Stream.flatMapToDouble(Function<? super T, ? extends DoubleStream> mapper) Returns anDoubleStreamconsisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.Stream.flatMapToInt(Function<? super T, ? extends IntStream> mapper) Returns anIntStreamconsisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.Stream.flatMapToLong(Function<? super T, ? extends LongStream> mapper) Returns anLongStreamconsisting of the results of replacing each element of this stream with the contents of a mapped stream produced by applying the provided mapping function to each element.Collectors.groupingBy(Function<? super T, ? extends K> classifier) Returns aCollectorimplementing a "group by" operation on input elements of typeT, grouping elements according to a classification function, and returning the results in aMap.Collectors.groupingBy(Function<? super T, ? extends K> classifier, Supplier<M> mapFactory, Collector<? super T, A, D> downstream) Returns aCollectorimplementing a cascaded "group by" operation on input elements of typeT, grouping elements according to a classification function, and then performing a reduction operation on the values associated with a given key using the specified downstreamCollector.Collectors.groupingBy(Function<? super T, ? extends K> classifier, Collector<? super T, A, D> downstream) Returns aCollectorimplementing a cascaded "group by" operation on input elements of typeT, grouping elements according to a classification function, and then performing a reduction operation on the values associated with a given key using the specified downstreamCollector.static <T,K> Collector <T, ?, ConcurrentMap<K, List<T>>> Collectors.groupingByConcurrent(Function<? super T, ? extends K> classifier) Returns a concurrentCollectorimplementing a "group by" operation on input elements of typeT, grouping elements according to a classification function.static <T,K, A, D, M extends ConcurrentMap<K, D>>
Collector<T, ?, M> Collectors.groupingByConcurrent(Function<? super T, ? extends K> classifier, Supplier<M> mapFactory, Collector<? super T, A, D> downstream) Returns a concurrentCollectorimplementing a cascaded "group by" operation on input elements of typeT, grouping elements according to a classification function, and then performing a reduction operation on the values associated with a given key using the specified downstreamCollector.static <T,K, A, D>
Collector<T, ?, ConcurrentMap<K, D>> Collectors.groupingByConcurrent(Function<? super T, ? extends K> classifier, Collector<? super T, A, D> downstream) Returns a concurrentCollectorimplementing a cascaded "group by" operation on input elements of typeT, grouping elements according to a classification function, and then performing a reduction operation on the values associated with a given key using the specified downstreamCollector.<R> Stream<R> Returns a stream consisting of the results of applying the given function to the elements of this stream.static <T,U, A, R>
Collector<T, ?, R> Adapts aCollectoraccepting elements of typeUto one accepting elements of typeTby applying a mapping function to each input element before accumulation.static <T,A, R> Collector <T, A, R> Collector.of(Supplier<A> supplier, BiConsumer<A, T> accumulator, BinaryOperator<A> combiner, Function<A, R> finisher, Collector.Characteristics... characteristics) Returns a newCollectordescribed by the givensupplier,accumulator,combiner, andfinisherfunctions.static <T,U> Collector <T, ?, U> Collectors.reducing(U identity, Function<? super T, ? extends U> mapper, BinaryOperator<U> op) Returns aCollectorwhich performs a reduction of its input elements under a specified mapping function andBinaryOperator.static <T,K, U> Collector <T, ?, ConcurrentMap<K, U>> Collectors.toConcurrentMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper) Returns a concurrentCollectorthat accumulates elements into aConcurrentMapwhose keys and values are the result of applying the provided mapping functions to the input elements.static <T,K, U> Collector <T, ?, ConcurrentMap<K, U>> Collectors.toConcurrentMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction) Returns a concurrentCollectorthat accumulates elements into aConcurrentMapwhose keys and values are the result of applying the provided mapping functions to the input elements.static <T,K, U, M extends ConcurrentMap<K, U>>
Collector<T, ?, M> Collectors.toConcurrentMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction, Supplier<M> mapFactory) Returns a concurrentCollectorthat accumulates elements into aConcurrentMapwhose keys and values are the result of applying the provided mapping functions to the input elements.Collectors.toMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper) Returns aCollectorthat accumulates elements into aMapwhose keys and values are the result of applying the provided mapping functions to the input elements.Collectors.toMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction) Returns aCollectorthat accumulates elements into aMapwhose keys and values are the result of applying the provided mapping functions to the input elements.Collectors.toMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction, Supplier<M> mapFactory) Returns aCollectorthat accumulates elements into aMapwhose keys and values are the result of applying the provided mapping functions to the input elements.Collectors.toUnmodifiableMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper) Returns aCollectorthat accumulates the input elements into an unmodifiable Map, whose keys and values are the result of applying the provided mapping functions to the input elements.Collectors.toUnmodifiableMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction) Returns aCollectorthat accumulates the input elements into an unmodifiable Map, whose keys and values are the result of applying the provided mapping functions to the input elements. -
Uses of Function in jdk.jshell
Methods in jdk.jshell with parameters of type FunctionModifier and TypeMethodDescriptionJShell.Builder.fileManager(Function<StandardJavaFileManager, StandardJavaFileManager> mapping) Configure theFileManagerto be used by compilation and source analysis.