com.programix.collections
Class CollectionsTools

java.lang.Object
  com.programix.collections.CollectionsTools

public class CollectionsTools
extends Object

Utility methods for working with the Collections API. Unless otherwise stated, these methods are not thread-safe.

Author:

Paul Hyde

See Also:

ReverseComparator, ComparableComparator, NullFirstComparator, NullLastComparator

Field Summary

static Comparator<Comparable<?>>	NULL_FIRST_COMPARABLE_ASC This Comparator sorts Comparable objects in their normal ordering, but with any null's that may be present sorted to the top.
static Comparator<Comparable<?>>	NULL_FIRST_COMPARABLE_DESC This Comparator sorts Comparable objects in their reverse ordering, but with any null's that may be present sorted to the top.
static Comparator<Comparable<?>>	NULL_LAST_COMPARABLE_ASC This Comparator sorts Comparable objects in their normal ordering, but with any null's that may be present sorted to the bottom.
static Comparator<Comparable<?>>	NULL_LAST_COMPARABLE_DESC This Comparator sorts Comparable objects in their reverse ordering, but with any null's that may be present sorted to the bottom.

Method Summary

static boolean	isEmpty(Collection<?> collection) Returns true if the passed reference is null or if the size of the collection is 0.
static boolean	isNotEmpty(Collection<?> collection) Returns true if the passed reference is not null and the size of the collection greater than 0.
static char[]	toCharArray(Collection<Character> charList) Converts a Collection holding instances of Character into a char[].
static int[]	toIntArray(Collection<? extends Number> integerList) Converts a collection of Number to an int[].
static String[]	toStringArray(Collection<String> strings)

Methods inherited from class java.lang.Object

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

Field Detail

NULL_FIRST_COMPARABLE_ASC

public static final Comparator<Comparable<?>> NULL_FIRST_COMPARABLE_ASC

This Comparator sorts Comparable objects in their normal ordering, but with any null's that may be present sorted to the top.

See Also:

NullFirstComparator, NullLastComparator, ReverseComparator, ComparableComparator

NULL_FIRST_COMPARABLE_DESC

public static final Comparator<Comparable<?>> NULL_FIRST_COMPARABLE_DESC

This Comparator sorts Comparable objects in their reverse ordering, but with any null's that may be present sorted to the top.

See Also:

NullFirstComparator, NullLastComparator, ReverseComparator, ComparableComparator

NULL_LAST_COMPARABLE_ASC

public static final Comparator<Comparable<?>> NULL_LAST_COMPARABLE_ASC

This Comparator sorts Comparable objects in their normal ordering, but with any null's that may be present sorted to the bottom.

See Also:

NullFirstComparator, NullLastComparator, ReverseComparator, ComparableComparator

NULL_LAST_COMPARABLE_DESC

public static final Comparator<Comparable<?>> NULL_LAST_COMPARABLE_DESC

This Comparator sorts Comparable objects in their reverse ordering, but with any null's that may be present sorted to the bottom.

See Also:

NullFirstComparator, NullLastComparator, ReverseComparator, ComparableComparator

Method Detail

toStringArray

public static String[] toStringArray(Collection<String> strings)

toIntArray

public static int[] toIntArray(Collection<? extends Number> integerList)

Converts a collection of Number to an int[].

toCharArray

public static char[] toCharArray(Collection<Character> charList)

Converts a Collection holding instances of Character into a char[].

isEmpty

public static boolean isEmpty(Collection<?> collection)

Returns true if the passed reference is null or if the size of the collection is 0.

isNotEmpty

public static boolean isNotEmpty(Collection<?> collection)

Returns true if the passed reference is not null and the size of the collection greater than 0.