Module org.apache.jena.arq

Package org.apache.jena.sparql.engine.join

Class JoinKey

java.lang.Object

org.apache.jena.sparql.engine.join.JoinKey

All Implemented Interfaces:

Iterable<Var>

public final class JoinKey
extends Object
implements Iterable<Var>

JoinKey for hash joins

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	JoinKey.Builder	The builder can emit a key every time build() is caller and it can be continued to be used.

Method Summary

Modifier and Type	Method	Description
static JoinKey	create(Collection<Var> vars1, Collection<Var> vars2)	Make a JoinKey from the intersection of two sets
static JoinKey	create(Var var)
static JoinKey	createVarKey(Collection<Var> vars1, Collection<Var> vars2)	Make a JoinKey of single variable from the intersection of two sets
Var	getVarKey()	Get a single variable for this key.
boolean	isEmpty()
Iterator<Var>	iterator()
int	length()
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Details

create

public static JoinKey create(Collection<Var> vars1,
 Collection<Var> vars2)

Make a JoinKey from the intersection of two sets

createVarKey

public static JoinKey createVarKey(Collection<Var> vars1,
 Collection<Var> vars2)

Make a JoinKey of single variable from the intersection of two sets

create

public static JoinKey create(Var var)

isEmpty

public boolean isEmpty()

length

public int length()

getVarKey

public Var getVarKey()

Get a single variable for this key. For any one key, it always returns the same var

iterator

public Iterator<Var> iterator()

Specified by:

iterator in interface Iterable<Var>

toString

public String toString()

Overrides:

toString in class Object