Package software.amazon.smithy.utils

Class ListUtils

java.lang.Object

software.amazon.smithy.utils.ListUtils

public final class ListUtils
extends Object

Immutable List utilities to polyfill Java 9+ features.

Method Summary

Modifier and Type	Method	Description
static <T> List<T>	copyOf(Collection<? extends T> values)	Creates an immutable copy of the given list.
static <T> List<T>	of()	Returns an unmodifiable list containing zero entries.
static <T> List<T>	of(T value)	Returns an unmodifiable list containing a single entry.
static <T> List<T>	of(T... values)	Returns an unmodifiable list containing any number of entries.
static <T> Collector<T,?,List<T>>	toUnmodifiableList()	Creates a collector that collects into an unmodifiable list.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

copyOf

public static <T> List<T> copyOf(Collection<? extends T> values)

Creates an immutable copy of the given list.

Type Parameters:

T - the List's value type.

Parameters:

values - The collection to make an immutable list of.

Returns:

An immutable List copy.

of

public static <T> List<T> of()

Returns an unmodifiable list containing zero entries.

Type Parameters:

T - the List's value type.

Returns:

an empty List.

of

public static <T> List<T> of(T value)

Returns an unmodifiable list containing a single entry.

Type Parameters:

T - the List's value type.

Parameters:

value - the List's value.

Returns:

a List containing the specified value.

Throws:

NullPointerException - if the value is null.

of

@SafeVarargs
public static <T> List<T> of(T... values)

Returns an unmodifiable list containing any number of entries.

Type Parameters:

T - the List's value type.

Parameters:

values - the List's values.

Returns:

a List containing the specified values.

Throws:

NullPointerException - if any value is null.

toUnmodifiableList

public static <T> Collector<T,?,List<T>> toUnmodifiableList()

Creates a collector that collects into an unmodifiable list.

This is a polyfill equivalent of Java 10's Collectors#toUnmodifiableList.

Type Parameters:

T - Type of value to expect.

Returns:

a Collector that accumulates the entries into an unmodifiable List.