CollectionUtils (Gradle API 8.7)

java.lang.Object
- org.gradle.util.CollectionUtils

```
@Deprecated
public abstract class CollectionUtils
extends java.lang.Object
```
Deprecated.
Will be removed in Gradle 9.0.

This class is only here to maintain binary compatibility with existing plugins.
Plugins should prefer external collection frameworks over this class. Internally, all code should use CollectionUtils.

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description
`static class`	`CollectionUtils.InjectionStep<T,I>`	Deprecated.
`static class`	`CollectionUtils.SetDiff<T>`	Deprecated. The result of diffing two sets.

Constructor Summary

Constructors
Constructor Description

CollectionUtils()
Deprecated.

Constructors
Constructor	Description
`CollectionUtils()`	Deprecated.

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static <T,C extends java.util.Collection<? super T>> C`	`addAll(C t1, java.lang.Iterable<? extends T> t2)`	Deprecated. Utility for adding an iterable to a collection.
`static <T,C extends java.util.Collection<? super T>> C`	`addAll(C t1, T... t2)`	Deprecated. Utility for adding an array to a collection.
`static <T> boolean`	`any(java.lang.Iterable<? extends T> source, Spec<? super T> filter)`	Deprecated.
`static <T> boolean`	`any(T[] source, Spec<? super T> filter)`	Deprecated.
`static java.lang.String`	`asCommandLine(java.lang.Iterable<java.lang.String> arguments)`	Deprecated.
`static <T> java.util.Collection<? extends T>`	`checkedCast(java.lang.Class<T> type, java.util.Collection<?> input)`	Deprecated.
`static <R,I> java.util.List<R>`	`collect(I[] list, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <R,I,C extends java.util.Collection<R>> C`	`collect(java.lang.Iterable<? extends I> source, C destination, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <R,I> java.util.List<R>`	`collect(java.lang.Iterable<? extends I> source, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <R,I> java.util.Set<R>`	`collect(java.util.Set<? extends I> set, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <R,I> R[]`	`collectArray(I[] list, java.lang.Class<R> newType, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <R,I> R[]`	`collectArray(I[] list, R[] destination, Transformer<? extends R,? super I> transformer)`	Deprecated.
`static <K,V> java.util.Map<K,V>`	`collectMap(java.lang.Iterable<? extends V> items, Transformer<? extends K,? super V> keyGenerator)`	Deprecated. Given a set of values, derive a set of keys and return a map
`static <K,V> void`	`collectMap(java.util.Map<K,V> destination, java.lang.Iterable<? extends V> items, Transformer<? extends K,? super V> keyGenerator)`	Deprecated.
`static <K,V> java.util.Map<K,V>`	`collectMapValues(java.lang.Iterable<? extends K> keys, Transformer<? extends V,? super K> keyGenerator)`	Deprecated. Given a set of keys, derive a set of values and return a map
`static <K,V> void`	`collectMapValues(java.util.Map<K,V> destination, java.lang.Iterable<? extends K> keys, Transformer<? extends V,? super K> keyGenerator)`	Deprecated.
`static <E> java.util.List<E>`	`compact(java.util.List<E> list)`	Deprecated.
`static <T> CollectionUtils.SetDiff<T>`	`diffSetsBy(java.util.Set<? extends T> left, java.util.Set<? extends T> right, Transformer<?,T> compareBy)`	Deprecated. Provides a “diff report” of how the two sets are similar and how they are different, comparing the entries by some aspect.
`static <T> boolean`	`every(java.lang.Iterable<? extends T> things, Spec<? super T> predicate)`	Deprecated.
`static <T,C extends java.util.Collection<T>> C`	`filter(java.lang.Iterable<? extends T> source, C destination, Spec<? super T> filter)`	Deprecated.
`static <T> java.util.List<T>`	`filter(java.util.List<? extends T> list, Spec<? super T> filter)`	Deprecated.
`static <K,V> java.util.Map<K,V>`	`filter(java.util.Map<K,V> map, java.util.Map<K,V> destination, Spec<java.util.Map.Entry<K,V>> filter)`	Deprecated.
`static <K,V> java.util.Map<K,V>`	`filter(java.util.Map<K,V> map, Spec<java.util.Map.Entry<K,V>> filter)`	Deprecated.
`static <T> java.util.Set<T>`	`filter(java.util.Set<? extends T> set, Spec<? super T> filter)`	Deprecated.
`static <T> java.util.List<T>`	`filter(T[] array, Spec<? super T> filter)`	Deprecated.
`static <T> T`	`findFirst(java.lang.Iterable<? extends T> source, Spec<? super T> filter)`	Deprecated.
`static <T> T`	`findFirst(T[] source, Spec<? super T> filter)`	Deprecated.
`static <T> T`	`findSingle(java.lang.Iterable<T> source)`	Deprecated. Returns null if the collection is empty otherwise expects a `single(Iterable)` element to be found.
`static <T> T`	`first(java.lang.Iterable<? extends T> source)`	Deprecated.
`static <T> java.util.List<T>`	`flattenCollections(java.lang.Class<T> type, java.lang.Object... things)`	Deprecated. Recursively unpacks all the given things into a flat list, ensuring they are of a certain type.
`static java.util.List<?>`	`flattenCollections(java.lang.Object... things)`	Deprecated. Recursively unpacks all the given things into a flat list.
`static <K,V> java.util.Map<K,java.util.Collection<V>>`	`groupBy(java.lang.Iterable<? extends V> iterable, Transformer<? extends K,V> grouper)`	Deprecated.
`static <T,I> T`	`inject(T target, java.lang.Iterable<? extends I> items, Action<CollectionUtils.InjectionStep<T,I>> action)`	Deprecated.
`static <T> java.util.List<T>`	`intersection(java.util.Collection<? extends java.util.Collection<T>> availableValuesByDescriptor)`	Deprecated.
`static java.lang.String`	`join(java.lang.String separator, java.lang.Iterable<?> objects)`	Deprecated. Creates a string with `toString()` of each object with the given separator.
`static java.lang.String`	`join(java.lang.String separator, java.lang.Object[] objects)`	Deprecated. Creates a string with `toString()` of each object with the given separator.
`static <T> java.util.List<T>`	`nonEmptyOrNull(java.lang.Iterable<T> iterable)`	Deprecated.
`static <T> org.gradle.internal.Pair<java.util.Collection<T>,java.util.Collection<T>>`	`partition(java.lang.Iterable<T> items, Spec<? super T> predicate)`	Deprecated. Partition given Collection into a Pair of Collections.
`static <E> boolean`	`replace(java.util.List<E> list, Spec<? super E> filter, Transformer<? extends E,? super E> transformer)`	Deprecated.
`static <T> T`	`single(java.lang.Iterable<? extends T> source)`	Deprecated. Returns the single element in the collection or throws.
`static <T> java.util.List<T>`	`sort(java.lang.Iterable<? extends T> things, java.util.Comparator<? super T> comparator)`	Deprecated. Returns a sorted copy of the provided collection of things.
`static <T extends java.lang.Comparable<T>> java.util.List<T>`	`sort(java.lang.Iterable<T> things)`	Deprecated. Returns a sorted copy of the provided collection of things.
`static <C extends java.util.Collection<java.lang.String>> C`	`stringize(java.lang.Iterable<?> source, C destination)`	Deprecated.
`static java.util.List<java.lang.String>`	`stringize(java.util.Collection<?> source)`	Deprecated.
`static <T> java.util.List<T>`	`toList(java.lang.Iterable<? extends T> things)`	Deprecated.
`static <T> java.util.List<T>`	`toList(java.util.Enumeration<? extends T> things)`	Deprecated.
`static <T> java.util.List<T>`	`toList(T[] things)`	Deprecated.
`static <T> java.util.Set<T>`	`toSet(java.lang.Iterable<? extends T> things)`	Deprecated.
`static java.util.List<java.lang.String>`	`toStringList(java.lang.Iterable<?> iterable)`	Deprecated.
`static <T> java.lang.Iterable<? extends T>`	`unpack(java.lang.Iterable<? extends org.gradle.internal.Factory<? extends T>> factories)`	Deprecated.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- CollectionUtils
```
public CollectionUtils()
```
  Deprecated.

Method Detail

findSingle
```
@Nullable
public static <T> T findSingle(java.lang.Iterable<T> source)
```
Deprecated.

Returns null if the collection is empty otherwise expects a single(Iterable) element to be found.

single

public static <T> T single(java.lang.Iterable<? extends T> source)

Deprecated.

Returns the single element in the collection or throws.

checkedCast

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

Deprecated.

findFirst

@Nullable
public static <T> T findFirst(java.lang.Iterable<? extends T> source,
                              Spec<? super T> filter)

Deprecated.

findFirst

@Nullable
public static <T> T findFirst(T[] source,
                              Spec<? super T> filter)

Deprecated.

first

public static <T> T first(java.lang.Iterable<? extends T> source)

Deprecated.

any

public static <T> boolean any(java.lang.Iterable<? extends T> source,
                              Spec<? super T> filter)

Deprecated.

any

public static <T> boolean any(T[] source,
                              Spec<? super T> filter)

Deprecated.

filter

public static <T> java.util.Set<T> filter(java.util.Set<? extends T> set,
                                          Spec<? super T> filter)

Deprecated.

filter

public static <T> java.util.List<T> filter(java.util.List<? extends T> list,
                                           Spec<? super T> filter)

Deprecated.

filter

public static <T> java.util.List<T> filter(T[] array,
                                           Spec<? super T> filter)

Deprecated.

sort

public static <T> java.util.List<T> sort(java.lang.Iterable<? extends T> things,
                                         java.util.Comparator<? super T> comparator)

Deprecated.

Returns a sorted copy of the provided collection of things. Uses the provided comparator to sort.

sort
```
public static <T extends java.lang.Comparable<T>> java.util.List<T> sort(java.lang.Iterable<T> things)
```
Deprecated.

Returns a sorted copy of the provided collection of things. Uses the natural ordering of the things.

filter

public static <T,C extends java.util.Collection<T>> C filter(java.lang.Iterable<? extends T> source,
                                                                   C destination,
                                                                   Spec<? super T> filter)

Deprecated.

filter

public static <K,V> java.util.Map<K,V> filter(java.util.Map<K,V> map,
                                                          Spec<java.util.Map.Entry<K,V>> filter)

Deprecated.

filter

public static <K,V> java.util.Map<K,V> filter(java.util.Map<K,V> map,
                                                          java.util.Map<K,V> destination,
                                                          Spec<java.util.Map.Entry<K,V>> filter)

Deprecated.

collectArray

public static <R,I> R[] collectArray(I[] list,
                                           java.lang.Class<R> newType,
                                           Transformer<? extends R,? super I> transformer)

Deprecated.

collectArray

public static <R,I> R[] collectArray(I[] list,
                                           R[] destination,
                                           Transformer<? extends R,? super I> transformer)

Deprecated.

collect

public static <R,I> java.util.List<R> collect(I[] list,
                                                    Transformer<? extends R,? super I> transformer)

Deprecated.

collect

public static <R,I> java.util.Set<R> collect(java.util.Set<? extends I> set,
                                                   Transformer<? extends R,? super I> transformer)

Deprecated.

collect

public static <R,I> java.util.List<R> collect(java.lang.Iterable<? extends I> source,
                                                    Transformer<? extends R,? super I> transformer)

Deprecated.

collect

public static <R,I,C extends java.util.Collection<R>> C collect(java.lang.Iterable<? extends I> source,
                                                                            C destination,
                                                                            Transformer<? extends R,? super I> transformer)

Deprecated.

toStringList

public static java.util.List<java.lang.String> toStringList(java.lang.Iterable<?> iterable)

Deprecated.

flattenCollections
```
public static java.util.List<?> flattenCollections(java.lang.Object... things)
```
Deprecated.

Recursively unpacks all the given things into a flat list. Nulls are not removed, they are left intact.

Parameters:

things - The things to flatten

Returns:

A flattened list of the given things

flattenCollections
```
public static <T> java.util.List<T> flattenCollections(java.lang.Class<T> type,
                                                       java.lang.Object... things)
```
Deprecated.

Recursively unpacks all the given things into a flat list, ensuring they are of a certain type. Nulls are not removed, they are left intact. If a non null object cannot be cast to the target type, a ClassCastException will be thrown.

Type Parameters:

T - The target type in the flattened list

Parameters:

things - The things to flatten

Returns:

A flattened list of the given things

toList

public static <T> java.util.List<T> toList(java.lang.Iterable<? extends T> things)

Deprecated.

toList

public static <T> java.util.List<T> toList(java.util.Enumeration<? extends T> things)

Deprecated.

intersection

public static <T> java.util.List<T> intersection(java.util.Collection<? extends java.util.Collection<T>> availableValuesByDescriptor)

Deprecated.

toList

public static <T> java.util.List<T> toList(T[] things)

Deprecated.

toSet

public static <T> java.util.Set<T> toSet(java.lang.Iterable<? extends T> things)

Deprecated.

compact

public static <E> java.util.List<E> compact(java.util.List<E> list)

Deprecated.

stringize

public static <C extends java.util.Collection<java.lang.String>> C stringize(java.lang.Iterable<?> source,
                                                                             C destination)

Deprecated.

stringize

public static java.util.List<java.lang.String> stringize(java.util.Collection<?> source)

Deprecated.

replace

public static <E> boolean replace(java.util.List<E> list,
                                  Spec<? super E> filter,
                                  Transformer<? extends E,? super E> transformer)

Deprecated.

collectMap

public static <K,V> void collectMap(java.util.Map<K,V> destination,
                                          java.lang.Iterable<? extends V> items,
                                          Transformer<? extends K,? super V> keyGenerator)

Deprecated.

collectMap

public static <K,V> java.util.Map<K,V> collectMap(java.lang.Iterable<? extends V> items,
                                                              Transformer<? extends K,? super V> keyGenerator)

Deprecated.

Given a set of values, derive a set of keys and return a map

collectMapValues

public static <K,V> void collectMapValues(java.util.Map<K,V> destination,
                                                java.lang.Iterable<? extends K> keys,
                                                Transformer<? extends V,? super K> keyGenerator)

Deprecated.

collectMapValues

public static <K,V> java.util.Map<K,V> collectMapValues(java.lang.Iterable<? extends K> keys,
                                                                    Transformer<? extends V,? super K> keyGenerator)

Deprecated.

Given a set of keys, derive a set of values and return a map

every

public static <T> boolean every(java.lang.Iterable<? extends T> things,
                                Spec<? super T> predicate)

Deprecated.

addAll
```
public static <T,C extends java.util.Collection<? super T>> C addAll(C t1,
                                                                           java.lang.Iterable<? extends T> t2)
```
Deprecated.

Utility for adding an iterable to a collection.

Type Parameters:

T - The element type of t1

Parameters:

t1 - The collection to add to

t2 - The iterable to add each item of to the collection

Returns:

t1

addAll
```
public static <T,C extends java.util.Collection<? super T>> C addAll(C t1,
                                                                           T... t2)
```
Deprecated.

Utility for adding an array to a collection.

Type Parameters:

T - The element type of t1

Parameters:

t1 - The collection to add to

t2 - The iterable to add each item of to the collection

Returns:

t1

diffSetsBy
```
public static <T> CollectionUtils.SetDiff<T> diffSetsBy(java.util.Set<? extends T> left,
                                                        java.util.Set<? extends T> right,
                                                        Transformer<?,T> compareBy)
```
Deprecated.

Provides a “diff report” of how the two sets are similar and how they are different, comparing the entries by some aspect. The transformer is used to generate the value to use to compare the entries by. That is, the entries are not compared by equals by an attribute or characteristic. The transformer is expected to produce a unique value for each entry in a single set. Behaviour is undefined if this condition is not met.

Type Parameters:

T - The type of the entry objects

Parameters:

left - The set on the “left” side of the comparison.

right - The set on the “right” side of the comparison.

compareBy - Provides the value to compare entries from either side by

Returns:

A representation of the difference

join
```
public static java.lang.String join(java.lang.String separator,
                                    java.lang.Object[] objects)
```
Deprecated.
Creates a string with toString() of each object with the given separator.
```
 expect:
 join(",", new Object[]{"a"}) == "a"
 join(",", new Object[]{"a", "b", "c"}) == "a,b,c"
 join(",", new Object[]{}) == ""
 
```
The separator must not be null and objects must not be null.
Parameters:

separator - The string by which to join each string representation

objects - The objects to join the string representations of

Returns:

The joined string

join
```
public static java.lang.String join(java.lang.String separator,
                                    java.lang.Iterable<?> objects)
```
Deprecated.
Creates a string with toString() of each object with the given separator.
```
 expect:
 join(",", ["a"]) == "a"
 join(",", ["a", "b", "c"]) == "a,b,c"
 join(",", []) == ""
 
```
The separator must not be null and objects must not be null.
Parameters:

separator - The string by which to join each string representation

objects - The objects to join the string representations of

Returns:

The joined string

partition

public static <T> org.gradle.internal.Pair<java.util.Collection<T>,java.util.Collection<T>> partition(java.lang.Iterable<T> items,
                                                                                                            Spec<? super T> predicate)

Deprecated.

Partition given Collection into a Pair of Collections.

Left

Collection containing entries that satisfy the given predicate

Right

Collection containing entries that do NOT satisfy the given predicate

inject

public static <T,I> T inject(T target,
                                   java.lang.Iterable<? extends I> items,
                                   Action<CollectionUtils.InjectionStep<T,I>> action)

Deprecated.

groupBy

public static <K,V> java.util.Map<K,java.util.Collection<V>> groupBy(java.lang.Iterable<? extends V> iterable,
                                                                                 Transformer<? extends K,V> grouper)

Deprecated.

unpack

public static <T> java.lang.Iterable<? extends T> unpack(java.lang.Iterable<? extends org.gradle.internal.Factory<? extends T>> factories)

Deprecated.

nonEmptyOrNull

@Nullable
public static <T> java.util.List<T> nonEmptyOrNull(java.lang.Iterable<T> iterable)

Deprecated.

asCommandLine

public static java.lang.String asCommandLine(java.lang.Iterable<java.lang.String> arguments)

Deprecated.

Class CollectionUtils

Nested Class Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

CollectionUtils

Method Detail

findSingle

single

checkedCast

findFirst

findFirst

first

any

any

filter

filter

filter

sort

sort

filter

filter

filter

collectArray

collectArray

collect

collect

collect

collect

toStringList

flattenCollections

flattenCollections

toList

toList

intersection

toList

toSet

compact

stringize

stringize

replace

collectMap

collectMap

collectMapValues

collectMapValues

every

addAll

addAll

diffSetsBy

join

join

partition

inject

groupBy

unpack

nonEmptyOrNull

asCommandLine