```
public interface ICollectionTools
```
ICollectionTools offers default implementations of Collection functionality.

See Also:

Collection

Method Summary

Static Methods
Modifier and Type	Method	Description
`static <E> boolean`	`containsIf(java.util.Collection<E> coll, java.util.function.Predicate<? super E> predicate)`	Determines whether the list contains a matching element.
`static <E> int`	`countIf(java.util.Collection<E> coll, java.util.function.Predicate<? super E> predicate)`	Counts how many elements in the list match the predicate.
`static <E,C extends java.util.Collection<E>> C`	`filter(java.util.Collection<E> coll, java.util.function.Predicate<? super E> predicate, java.util.function.Supplier<C> factory)`	Create a new list by applying the specified filter to all elements.
`static <E,R,C extends java.util.Collection<R>> IList<R>`	`filterMap(java.util.Collection<E> coll, java.util.function.Predicate<E> filter, java.util.function.Function<E,R> func)`	Create a new list by applying the specified filter first and then the mapping function to all elements selected.
`static <E,R,C extends java.util.Collection<R>> C`	`filterMap(java.util.Collection<E> coll, java.util.function.Predicate<E> filter, java.util.function.Function<E,R> func, java.util.function.Supplier<C> factory)`	Create a new collection by applying the specified filter first and then the mapping function to all elements selected.
`static <E,R,RC extends java.util.Collection<R>,C extends java.util.Collection<R>> C`	`flatMap(java.util.Collection<E> coll, java.util.function.Function<E,RC> func, java.util.function.Supplier<C> factory)`	Create a new list by applying the specified mapping function to all elements.
`static <E> E`	`getFirst(java.util.Collection<E> coll)`	Returns the first element stored in the collection.
`static <E> E`	`getFirstOrNull(java.util.Collection<E> coll)`	Returns the first element stored in the collection.
`static <E> E`	`getIf(java.util.Collection<E> coll, java.util.function.Predicate<? super E> predicate)`	Returns the first element stored in the collection which matches the predicate.
`static <E> E`	`getSingle(java.util.Collection<E> coll)`	Returns the only element stored in the collection.
`static <E> E`	`getSingleOrNull(java.util.Collection<E> coll)`	Returns the only element stored in the collection or null if the collection is empty.
`static <E,R,C extends java.util.Collection<R>> C`	`map(java.util.Collection<E> coll, java.util.function.Function<E,R> func, java.util.function.Supplier<C> factory)`	Create a new list by applying the specified mapping function to all elements.
`static <E,R> IList<R>`	`mapFilter(java.util.Collection<E> coll, java.util.function.Function<E,R> func, java.util.function.Predicate<R> filter)`	Create a new list by applying the specified mapping function to all elements and then filtering it.
`static <E,R,C extends java.util.Collection<R>> C`	`mapFilter(java.util.Collection<E> coll, java.util.function.Function<E,R> func, java.util.function.Predicate<R> filter, java.util.function.Supplier<C> factory)`	Create a new collection by applying the specified mapping function to all elements and then filtering it.

Method Detail

getFirst
```
static <E> E getFirst(java.util.Collection<E> coll)
```
Returns the first element stored in the collection. If the collection is empty, a NoSuchElementException is thrown.

Returns:

first element stored in the collection

getFirstOrNull
```
static <E> E getFirstOrNull(java.util.Collection<E> coll)
```
Returns the first element stored in the collection. If the collection is empty, null is returned.

Returns:

first element stored in the collection or null if empty

getSingle
```
static <E> E getSingle(java.util.Collection<E> coll)
```
Returns the only element stored in the collection. If the collection size is not 1, a NoSuchElementException is thrown.

Returns:

only element stored in the collection

getSingleOrNull
```
static <E> E getSingleOrNull(java.util.Collection<E> coll)
```
Returns the only element stored in the collection or null if the collection is empty. If the collection's size is greater than 1, a NoSuchElementException is thrown.

Returns:

only element stored in the collection or null if empty

getIf
```
static <E> E getIf(java.util.Collection<E> coll,
                   java.util.function.Predicate<? super E> predicate)
```
Returns the first element stored in the collection which matches the predicate. If the collection is empty of no element matches, null is returned.

Returns:

first element matching the predicate or null if not founds

containsIf
```
static <E> boolean containsIf(java.util.Collection<E> coll,
                              java.util.function.Predicate<? super E> predicate)
```
Determines whether the list contains a matching element.

Parameters:

predicate - predicate used to search element

Returns:

true if the list contains a matching element, false otherwise

countIf
```
static <E> int countIf(java.util.Collection<E> coll,
                       java.util.function.Predicate<? super E> predicate)
```
Counts how many elements in the list match the predicate.

Parameters:

predicate - a predicate which returns true for elements to be counted

Returns:

count how many elements in the list match the predicate

filter

static <E,C extends java.util.Collection<E>> C filter(java.util.Collection<E> coll,
                                                            java.util.function.Predicate<? super E> predicate,
                                                            java.util.function.Supplier<C> factory)

Create a new list by applying the specified filter to all elements.

Parameters:: predicate - filter predicate
Returns:: created list

map

static <E,R,C extends java.util.Collection<R>> C map(java.util.Collection<E> coll,
                                                                 java.util.function.Function<E,R> func,
                                                                 java.util.function.Supplier<C> factory)

Create a new list by applying the specified mapping function to all elements.

Parameters:: func - mapping function
Returns:: created list

flatMap

static <E,R,RC extends java.util.Collection<R>,C extends java.util.Collection<R>> C flatMap(java.util.Collection<E> coll,
                                                                                                              java.util.function.Function<E,RC> func,
                                                                                                              java.util.function.Supplier<C> factory)

Create a new list by applying the specified mapping function to all elements.

Parameters:: func - mapping function
Returns:: created list

mapFilter

static <E,R> IList<R> mapFilter(java.util.Collection<E> coll,
                                      java.util.function.Function<E,R> func,
                                      java.util.function.Predicate<R> filter)

Create a new list by applying the specified mapping function to all elements and then filtering it.

Parameters:: func - mapping function; filter - filter predicate
Returns:: created list

mapFilter

static <E,R,C extends java.util.Collection<R>> C mapFilter(java.util.Collection<E> coll,
                                                                       java.util.function.Function<E,R> func,
                                                                       java.util.function.Predicate<R> filter,
                                                                       java.util.function.Supplier<C> factory)

Create a new collection by applying the specified mapping function to all elements and then filtering it.

Parameters:: func - mapping function; filter - filter predicate; factory - factory to create collection
Returns:: created list

filterMap

static <E,R,C extends java.util.Collection<R>> IList<R> filterMap(java.util.Collection<E> coll,
                                                                              java.util.function.Predicate<E> filter,
                                                                              java.util.function.Function<E,R> func)

Create a new list by applying the specified filter first and then the mapping function to all elements selected.

Parameters:: filter - filter predicate; func - mapping function
Returns:: created list

filterMap

static <E,R,C extends java.util.Collection<R>> C filterMap(java.util.Collection<E> coll,
                                                                       java.util.function.Predicate<E> filter,
                                                                       java.util.function.Function<E,R> func,
                                                                       java.util.function.Supplier<C> factory)

Create a new collection by applying the specified filter first and then the mapping function to all elements selected.

Parameters:: filter - filter predicate; func - mapping function; factory - factory to create collection
Returns:: created list

Interface ICollectionTools

Method Summary

Method Detail

getFirst

getFirstOrNull

getSingle

getSingleOrNull

getIf

containsIf

countIf

filter

map

flatMap

mapFilter

mapFilter

filterMap

filterMap