com.nomagic.utils

Class CollectionUtils

java.lang.Object

com.nomagic.utils.CollectionUtils

@OpenApiAll
public class CollectionUtils
extends java.lang.Object

Collection related utility methods.

Constructor Summary

Constructors

Constructor and Description
CollectionUtils()

Method Summary

Modifier and Type	Method and Description
static <T> java.util.Collection<T>	append(java.util.Collection<T> target, java.util.Collection<? extends T> source, boolean allowDuplication) Append source to target collection.
static <T> java.util.Collection<T>	append(java.util.Collection<T> target, java.util.Iterator<? extends T> sourceIterator, boolean allowDuplication) Append source to target collection.
static <T> java.util.Collection<T>	append(java.util.Collection<T> target, java.util.Iterator<? extends T> sourceIterator, boolean allowDuplication, boolean allowNulls) Append source to target collection.
static <T> java.util.Collection<T>	append(java.util.Collection<T> target, T[] source, boolean allowDuplication) Append source array to target collection.
static boolean	contains(java.util.Iterator it, java.lang.Object o) Checks if given iterator contains given object.
static boolean	containsAny(java.util.Collection location, java.util.Collection what) Returns true if location contains any element from what
static <S,T,C extends java.util.Collection<T>> C	convert(java.util.Collection<S> source, C target, Converter<? super S,? super T> converter) Convert one (source) collection into another (target) collection.
static <C extends java.util.Collection<E>,E> C	createCollection(java.lang.Class<C> collection, java.util.Iterator<E> it) Creates given type collection and fills it with objects from given iterator
static <T> java.util.Collection<T>	createFromStringRepresentation(java.lang.String string, java.lang.String delimiter, Converter<java.lang.String,T> converter) Create collection from string.
static <T> java.lang.String	createStringRepresentation(java.util.Collection<T> collection, java.lang.String delimiter, Converter<T,java.lang.String> converter) Create string representation of given collection.
static boolean	equals(java.util.Collection<?> collection1, java.util.Collection<?> collection2) Checks if both collections are equal - size the same and elements by order are the same
static <T> java.util.List<T>	filterByClassType(java.util.Collection<?> input, java.lang.Class<T> type) Filters and casts collection from one type to another
static void	leaveElements(java.util.List elements, int numberToLeave) Leaves a given number of first elements in the collection.
static java.lang.String	mapToString(java.util.Map<java.lang.String,java.lang.String> map) Serializes map to string.
static <T> java.util.Collection<T>	notDublicatedList(java.util.Collection<T> collection) Deprecated. use notDuplicatedList(java.util.Collection)
static <T> java.util.Collection<T>	notDuplicatedList(java.util.Collection<T> collection) Removes duplicates from given collection.
static <T> void	setFirstValue(java.util.Collection<T> collection, T value) Set first value of the given collection.
static <T> void	setSingleValue(java.util.Collection<T> collection, T value) Removes all values from a given collection and adds a new one.
static java.util.Map<java.lang.String,java.lang.String>	stringToMap(java.lang.String input) Deserialize map from string.
static <T> java.util.Collection<T>	toOptimizedContainsCollection(java.util.Collection<T> collection) Wrap the specified collection into containable collection that ensures optimized {{Collection.contains()}} performance.

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

convert

public static <S,T,C extends java.util.Collection<T>> C convert(java.util.Collection<S> source,
                                                                C target,
                                                                Converter<? super S,? super T> converter)

Convert one (source) collection into another (target) collection. Converts each source element and adds converted element to target collection.

Type Parameters:

S - source collection element type.

T - target collection element type.

C - target collection type.

Parameters:

source - source collection.

target - target collection.

converter - converts each element.

Returns:

target collection.

append

public static <T> java.util.Collection<T> append(java.util.Collection<T> target,
                                                 java.util.Collection<? extends T> source,
                                                 boolean allowDuplication)

Append source to target collection.

Parameters:

target - target

source - source

allowDuplication - do not check for already added element if true

Returns:

appended collection

append

public static <T> java.util.Collection<T> append(java.util.Collection<T> target,
                                                 java.util.Iterator<? extends T> sourceIterator,
                                                 boolean allowDuplication)

Append source to target collection.

Parameters:

target - target

sourceIterator - source iterator.

allowDuplication - do not check for already added element if true

Returns:

appended collection

append

public static <T> java.util.Collection<T> append(java.util.Collection<T> target,
                                                 java.util.Iterator<? extends T> sourceIterator,
                                                 boolean allowDuplication,
                                                 boolean allowNulls)

Append source to target collection.

Parameters:

target - target

sourceIterator - source iterator.

allowDuplication - do not check for already added element if true

allowNulls - allows nulls

Returns:

appended collection

append

public static <T> java.util.Collection<T> append(java.util.Collection<T> target,
                                                 T[] source,
                                                 boolean allowDuplication)

Append source array to target collection.

Parameters:

target - target

source - source

allowDuplication - do not check for already added element if true

Returns:

appended vector

contains

public static boolean contains(java.util.Iterator it,
                               java.lang.Object o)

Checks if given iterator contains given object.

Parameters:

it - the iterator.

o - the object.

Returns:

true, if it contains o.

containsAny

public static boolean containsAny(java.util.Collection location,
                                  java.util.Collection what)

Returns true if location contains any element from what

Parameters:

location - location collection

what - what collection.

Returns:

boolean.

createCollection

public static <C extends java.util.Collection<E>,E> C createCollection(java.lang.Class<C> collection,
                                                                       java.util.Iterator<E> it)

Creates given type collection and fills it with objects from given iterator

Parameters:

collection - type collection.

it - The given iterator.

Returns:

the result collection.

notDuplicatedList

public static <T> java.util.Collection<T> notDuplicatedList(java.util.Collection<T> collection)

Removes duplicates from given collection. After remove one element will be in collection only one time.

Parameters:

collection - collection to operate with. (makes sense when col are list (sets cant have identical elements).

Returns:

collection.

notDublicatedList

@Deprecated
public static <T> java.util.Collection<T> notDublicatedList(java.util.Collection<T> collection)

Deprecated. use notDuplicatedList(java.util.Collection)

Removes duplicates from given collection. After remove one element will be in collection only one time.

Parameters:

collection - collection to operate with. (makes sense when col are list (sets cant have identical elements).

Returns:

collection.

createStringRepresentation

public static <T> java.lang.String createStringRepresentation(java.util.Collection<T> collection,
                                                              java.lang.String delimiter,
                                                              Converter<T,java.lang.String> converter)

Create string representation of given collection.

Parameters:

collection - collection.

delimiter - values delimiter.

converter - convert object to string.

Returns:

string representation of collection.

createFromStringRepresentation

public static <T> java.util.Collection<T> createFromStringRepresentation(java.lang.String string,
                                                                         java.lang.String delimiter,
                                                                         Converter<java.lang.String,T> converter)

Create collection from string.

Parameters:

string - string representation.

delimiter - values delimiter.

converter - convert string to object.

Returns:

collection.

leaveElements

public static void leaveElements(java.util.List elements,
                                 int numberToLeave)

Leaves a given number of first elements in the collection.

Parameters:

elements - elements to filter.

numberToLeave - number of elements to leave.

mapToString

@Nonnull
public static java.lang.String mapToString(@Nonnull
                                                    java.util.Map<java.lang.String,java.lang.String> map)

Serializes map to string.

Parameters:

map - map to serialize.

Returns:

string representation of the map.

stringToMap

@Nonnull
public static java.util.Map<java.lang.String,java.lang.String> stringToMap(@Nonnull
                                                                                    java.lang.String input)

Deserialize map from string.

Parameters:

input - input string.

Returns:

map.

filterByClassType

public static <T> java.util.List<T> filterByClassType(java.util.Collection<?> input,
                                                      java.lang.Class<T> type)

Filters and casts collection from one type to another

Type Parameters:

T - type

Parameters:

input - input collection

type - desired output collection type

Returns:

new typed list

setSingleValue

public static <T> void setSingleValue(java.util.Collection<T> collection,
                                      T value)

Removes all values from a given collection and adds a new one.

Parameters:

collection - collection

value - a new value

setFirstValue

public static <T> void setFirstValue(java.util.Collection<T> collection,
                                     @CheckForNull
                                     T value)

Set first value of the given collection. If collection is empty, adds a new value. If value is null, removes first value from collection.

Parameters:

collection - collection

value - a new value

toOptimizedContainsCollection

public static <T> java.util.Collection<T> toOptimizedContainsCollection(java.util.Collection<T> collection)

Wrap the specified collection into containable collection that ensures optimized {{Collection.contains()}} performance. The provided collection should not change while the wrapped collection is used.

Parameters:

collection - a collection to wrap into containable collection

Returns:

return wrapped collection.

equals

public static boolean equals(java.util.Collection<?> collection1,
                             java.util.Collection<?> collection2)

Checks if both collections are equal - size the same and elements by order are the same

Parameters:

collection1 - first collection

collection2 - second collection

Returns:

true if size the same and elements by order are the same