org.dspace.content

Class ItemComparator

java.lang.Object

org.dspace.content.ItemComparator

All Implemented Interfaces:

Serializable, Comparator

public class ItemComparator
extends Object
implements Comparator, Serializable

Compare two Items by their DCValues. The DCValues to be compared are specified by the element, qualifier and language parameters to the constructor. If the Item has more than one matching Metadatum, then the max parameter to the constructor specifies whether the maximum or minimum lexicographic value will be used.

Version:

$Revision$

Author:

Peter Breton

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ItemComparator(String element, String qualifier, String language, boolean max) Constructor.

Method Summary

Modifier and Type	Method and Description
int	compare(Object first, Object second) Compare two Items by checking their DCValues for element, qualifier, and language.
boolean	equals(Object obj) Return true if the object is equal to this one, false otherwise.
int	hashCode()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

ItemComparator

public ItemComparator(String element,
                      String qualifier,
                      String language,
                      boolean max)

Constructor.

Parameters:

element - The Dublin Core element

qualifier - The Dublin Core qualifier

language - The language for the DCValues

max - If true, and there is more than one Metadatum for element, qualifier and language, then use the maximum value lexicographically; otherwise use the minimum value.

Method Detail

compare

public int compare(Object first,
                   Object second)

Compare two Items by checking their DCValues for element, qualifier, and language.

Return >= 1 if the first is lexicographically greater than the second; <= -1 if the second is lexicographically greater than the first, and 0 otherwise.

Specified by:

compare in interface Comparator

Parameters:

first - The first object to compare. Must be an object of type org.dspace.content.Item.

second - The second object to compare. Must be an object of type org.dspace.content.Item.

Returns:

>= 1 if the first is lexicographically greater than the second; <= -1 if the second is lexicographically greater than the first, and 0 otherwise.

equals

public boolean equals(Object obj)

Return true if the object is equal to this one, false otherwise. Another object is equal to this one if it is also an ItemComparator, and has the same values for element, qualifier, language, and max.

Specified by:

equals in interface Comparator

Overrides:

equals in class Object

Parameters:

obj - The object to compare to.

Returns:

True if the other object is equal to this one, false otherwise.

hashCode

public int hashCode()

Overrides:

hashCode in class Object