com.thebuzzmedia.exiftool.commons.iterables

Class Collections

java.lang.Object

com.thebuzzmedia.exiftool.commons.iterables.Collections

public final class Collections
extends Object

Static Collection Utilities.

Method Summary

Modifier and Type	Method and Description
static <T,U> Map<U,T>	indexBy(Iterable<T> inputs, Mapper<T,U> indexer) Index list of inputs by result of mapper function.
static <T> boolean	isEmpty(Collection<T> values) Check if collection is empty (null or empty).
static <T> String	join(Collection<T> values, String separator) Join elements of collection to a final string.
static <T,U> List<U>	map(List<T> inputs, Mapper<T,U> mapper) Map list of inputs to a new list of outputs.
static <T> int	size(Collection<T> values) Get size of collection.

Methods inherited from class java.lang.Object

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

Method Detail

isEmpty

public static <T> boolean isEmpty(Collection<T> values)

Check if collection is empty (null or empty).

Type Parameters:

T - Type of element in collection.

Parameters:

values - Collection of values.

Returns:

True if collection is empty (null or empty), false otherwise.

size

public static <T> int size(Collection<T> values)

Get size of collection. If collection is empty (null or empty), zero will be returned.

Type Parameters:

T - Type of element in collection.

Parameters:

values - Collection of values.

Returns:

Size of collection.

join

public static <T> String join(Collection<T> values,
                              String separator)

Join elements of collection to a final string. If collection is empty (null or empty), an empty string is returned.

Type Parameters:

T - Type of element in collection.

Parameters:

values - Collection of values.

separator - Separator, use to separate each elements.

Returns:

Final string.

map

public static <T,U> List<U> map(List<T> inputs,
                                Mapper<T,U> mapper)

Map list of inputs to a new list of outputs.

Type Parameters:

T - Type of input.

U - Type of output.

Parameters:

inputs - Input list.

mapper - Mapper used to transform inputs.

Returns:

New list of outputs.

indexBy

public static <T,U> Map<U,T> indexBy(Iterable<T> inputs,
                                     Mapper<T,U> indexer)

Index list of inputs by result of mapper function.

Type Parameters:

T - Type of input.

U - Type of index keys.

Parameters:

inputs - List of inputs.

indexer - Mapper function.

Returns:

Map of key (result of mapper function) with values (inputs).