Package uk.gov.gchq.gaffer.data.element.comparison

Class ElementPropertyComparator

java.lang.Object

uk.gov.gchq.gaffer.data.element.comparison.ElementPropertyComparator

All Implemented Interfaces:

Comparator<Element>, ElementComparator

public class ElementPropertyComparator
extends Object
implements ElementComparator

An ElementComparator implementation to use when making comparisons based on a single element property (e.g. a count field).

You must provide the property name and the set of element groups that contain that property.

Any elements that are compared that are not in one of the provided groups will be returned 'last' in the result.

Any elements that are compared that do not have the provided property will also be returned 'last' in the result.

There is a reversed option to allow you to flip the comparison value.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ElementPropertyComparator.Builder

Constructor Summary

Constructors

Constructor	Description
ElementPropertyComparator()

Method Summary

Modifier and Type	Method	Description
int	_compare(Object val1, Object val2)
int	compare(Element e1, Element e2)
Set<Pair<String,String>>	getComparableGroupPropertyPairs()	This should return a set all properties that the comparator requires to be of type Comparable.
Comparator	getComparator()
Set<String>	getGroups()
String	getProperty()
boolean	isReversed()
void	setComparator(Comparator comparator)
void	setGroups(Set<String> groups)
void	setProperty(String property)
void	setReversed(boolean reversed)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Comparator

equals, reversed, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

ElementPropertyComparator

public ElementPropertyComparator()

Method Detail

compare

public int compare(Element e1,
                   Element e2)

Specified by:

compare in interface Comparator<Element>

_compare

public int _compare(Object val1,
                    Object val2)

getComparableGroupPropertyPairs

public Set<Pair<String,String>> getComparableGroupPropertyPairs()

Description copied from interface: ElementComparator

This should return a set all properties that the comparator requires to be of type Comparable. As properties are associated with a Group we need to return Group,Property pairs. This is used to validate the the ElementComparator against the schema.

Specified by:

getComparableGroupPropertyPairs in interface ElementComparator

Returns:

set of group,property pairs, in which all properties are required to be comparable.

getProperty

public String getProperty()

setProperty

public void setProperty(String property)

getGroups

public Set<String> getGroups()

setGroups

public void setGroups(Set<String> groups)

isReversed

public boolean isReversed()

setReversed

public void setReversed(boolean reversed)

getComparator

public Comparator getComparator()

setComparator

public void setComparator(Comparator comparator)