software.amazon.awssdk.utils

Class CollectionUtils

java.lang.Object

software.amazon.awssdk.utils.CollectionUtils

public class CollectionUtils
extends Object

Constructor Summary

Constructors

Constructor and Description
CollectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T,U> Map<T,List<U>>	deepCopiedUnmodifiableMap(Map<T,? extends List<U>> map) Perform a deep copy of the provided map of lists, and make the result unmodifiable.
static <T,U> Map<T,List<U>>	deepCopyMap(Map<T,? extends List<U>> map) Perform a deep copy of the provided map of lists.
static <T,U> Map<T,List<U>>	deepUnmodifiableLinkedMap(Map<T,? extends List<U>> map) Create an unmodifiable version of the provdied map of lists.
static <T,U> Map<T,List<U>>	deepUnmodifiableMap(Map<T,? extends List<U>> map) Create an unmodifiable version of the provdied map of lists.
static <T> boolean	isNullOrEmpty(Collection<T> collection)
static String	join(Collection<String> toJoin, String separator) Joins a collection of strings with the given separator into a single string.
static <T> List<T>	mergeLists(List<T> list1, List<T> list2) Returns a new list containing the second list appended to the first list.

Methods inherited from class java.lang.Object

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

Constructor Detail

CollectionUtils

public CollectionUtils()

Method Detail

isNullOrEmpty

public static <T> boolean isNullOrEmpty(Collection<T> collection)

mergeLists

public static <T> List<T> mergeLists(List<T> list1,
                                     List<T> list2)

Returns a new list containing the second list appended to the first list.

join

public static String join(Collection<String> toJoin,
                          String separator)

Joins a collection of strings with the given separator into a single string.

Parameters:

toJoin - Collection containing items to join.

separator - String to join items with.

Returns:

Empty string if collection is null or empty. Otherwise joins all strings in the collection with the separator.

deepCopyMap

public static <T,U> Map<T,List<U>> deepCopyMap(Map<T,? extends List<U>> map)

Perform a deep copy of the provided map of lists. This only performs a deep copy of the map and lists. Entries are not copied, so care should be taken to ensure that entries are immutable if preventing unwanted mutations of the elements is desired.

deepUnmodifiableMap

public static <T,U> Map<T,List<U>> deepUnmodifiableMap(Map<T,? extends List<U>> map)

Create an unmodifiable version of the provdied map of lists. Modifications of the original map will not "write through" to the unmodifiable map, but modifications of the original list will. For true immutability, ensure that the original map is first copied with deepCopyMap(Map), or use deepCopiedUnmodifiableMap(Map)

deepUnmodifiableLinkedMap

public static <T,U> Map<T,List<U>> deepUnmodifiableLinkedMap(Map<T,? extends List<U>> map)

Create an unmodifiable version of the provdied map of lists. Modifications of the original map will not "write through" to the unmodifiable map, but modifications of the original list will. For true immutability, ensure that the original map is first copied with deepCopyMap(Map), or use deepCopiedUnmodifiableMap(Map)

deepCopiedUnmodifiableMap

public static <T,U> Map<T,List<U>> deepCopiedUnmodifiableMap(Map<T,? extends List<U>> map)

Perform a deep copy of the provided map of lists, and make the result unmodifiable. This is slightly more efficient than calling deepCopyMap(Map) followed by deepUnmodifiableMap(Map), because only one intermediate map copy is created.