Guava: Google Core Libraries for Java 33.1.0-jre · com.google.common.base.Functions

Static utility methods pertaining to com.google.common.base.Function instances; see that class for information about migrating to java.util.function.

All methods return serializable functions as long as they're given serializable parameters.

See the Guava User Guide article on the use of Function.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	Functions.ConstantFunction<E extends @Nullable Object>
private static class	Functions.ForMapWithDefault<K extends @Nullable Object, V extends @Nullable Object>
private static class	Functions.FunctionComposition<A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object>
private static class	Functions.FunctionForMapNoDefault<K extends @Nullable Object, V extends @Nullable Object>
private static enum	Functions.IdentityFunction
private static class	Functions.PredicateFunction<T extends @Nullable Object>
private static class	Functions.SupplierFunction<F extends @Nullable Object, T extends @Nullable Object>
private static enum	Functions.ToStringFunction

Constructor Summary

Access	Constructor and Description
private	Functions()

Method Summary

Modifier and Type	Method and Description
public static <A extends @Nullable Object, B extends @Nullable Object, C extends @Nullable Object> Function<A, C>	Returns: the composition of `f` and `g` compose(Function<B, C> the second function to apply g, Function<A, ? extends B> the first function to apply f) Returns the composition of two functions.
public static <E extends @Nullable Object> Function<@Nullable Object, E>	Returns: a function that always returns `value` constant(E the constant value for the function to return value) Returns a function that ignores its input and always returns `value`.
public static <K extends @Nullable Object, V extends @Nullable Object> Function<K, V>	forMap(Map<K, V> map) Returns a function which performs a map lookup.
public static <K extends @Nullable Object, V extends @Nullable Object> Function<K, V>	Returns: function that returns `map.get(a)` when `a` is a key, or `defaultValue` otherwise forMap(Map<K, ? extends V> source map that determines the function behavior map, V the value to return for inputs that aren't map keys defaultValue) Returns a function which performs a map lookup with a default value.
public static <T extends @Nullable Object> Function<T, Boolean>	forPredicate(Predicate<T> predicate) Creates a function that returns the same boolean output as the given predicate for all inputs.
public static <F extends @Nullable Object, T extends @Nullable Object> Function<F, T>	forSupplier(Supplier<T> supplier) Returns a function that ignores its input and returns the result of `supplier.get()`.
public static <E extends @Nullable Object> Function<E, E>	identity() Returns the identity function.
public static Function<Object, String>	toStringFunction() A function equivalent to the method reference `Object::toString`, for users not yet using Java 8.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

public final Class Functions

Nested and Inner Type Summary

Constructor Summary

Method Summary