org.lenskit.data.dao

Class SortKey

java.lang.Object

org.lenskit.data.dao.SortKey

public final class SortKey
extends Object

A sort key describing a sort operation.

Method Summary

Modifier and Type	Method and Description
static SortKey	create(TypedName<? extends Comparable> attr) Create a new sort key in ascending order.
static SortKey	create(TypedName<? extends Comparable> attr, SortOrder ord) Create a new sort key.
static <T> SortKey	create(TypedName<T> attr, Comparator<? super T> comp) Create a new sort key with a value comparator.
boolean	equals(Object o)
TypedName<?>	getAttribute() Get the attribute to sort by.
SortOrder	getOrder() Get the sort order.
boolean	hasCustomComparator() Query whether this sort key has a custom comparator.
int	hashCode()
Ordering<Entity>	ordering() Create an ordering (comparator) over entities from this sort key.

Methods inherited from class java.lang.Object

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

Method Detail

create

public static SortKey create(TypedName<? extends Comparable> attr)

Create a new sort key in ascending order.

Parameters:

attr - The attribute.

create

public static SortKey create(TypedName<? extends Comparable> attr,
                             SortOrder ord)

Create a new sort key.

Parameters:

attr - The attribute.

ord - The sort order.

create

public static <T> SortKey create(TypedName<T> attr,
                                 Comparator<? super T> comp)

Create a new sort key with a value comparator.

Parameters:

attr - The attribute.

comp - A comparator to use.

getAttribute

public TypedName<?> getAttribute()

Get the attribute to sort by.

Returns:

The attribute to sort by.

getOrder

@Nullable
public SortOrder getOrder()

Get the sort order.

Returns:

The sort order.

hasCustomComparator

public boolean hasCustomComparator()

Query whether this sort key has a custom comparator.

Returns:

The custom value comparator.

ordering

public Ordering<Entity> ordering()

Create an ordering (comparator) over entities from this sort key.

Returns:

An ordering over entities.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object