AggNull (Apache Jena ARQ)

java.lang.Object

org.apache.jena.sparql.expr.aggregate.AggregatorBase

org.apache.jena.sparql.expr.aggregate.AggNull

All Implemented Interfaces:: Aggregator

public class AggNull extends AggregatorBase

The null aggregate (which can't be written in SPARQL) calculates nothing but does help remember the group key.

Constructor Summary

Constructors

Constructor

Description

AggNull()
Method Summary

Modifier and Type

Method

Description

Aggregator

copy(ExprList exprs)

static Accumulator

createAccNull()

Accumulator

createAccumulator()

Create an accumulator for this aggregator

boolean

equals(Aggregator other, boolean bySyntax)

Consider this 'protected'

org.apache.jena.graph.Node

getValueEmpty()

Value if there are no groups : return null for no result

int

hashCode()

Methods inherited from class org.apache.jena.sparql.expr.aggregate.AggregatorBase
asSparqlExpr, copyTransform, equals, getExprList, getName, getValue, key, toPrefixString, toString

Methods inherited from class java.lang.Object
getClass, notify, notifyAll, wait, wait, wait

Constructor Details
- AggNull
  
  public AggNull()
Method Details
- copy
  
  public Aggregator copy(ExprList exprs)
- createAccumulator
  
  public Accumulator createAccumulator()
  
  Description copied from interface: Aggregator
  
  Create an accumulator for this aggregator
  
  Specified by:
  
  createAccumulator in interface Aggregator
  
  Specified by:
  
  createAccumulator in class AggregatorBase
- getValueEmpty
  
  public org.apache.jena.graph.Node getValueEmpty()
  
  Description copied from interface: Aggregator
  
  Value if there are no groups : return null for no result
  
  Specified by:
  
  getValueEmpty in interface Aggregator
  
  Specified by:
  
  getValueEmpty in class AggregatorBase
- hashCode
  
  public int hashCode()
  
  Specified by:
  
  hashCode in interface Aggregator
  
  Specified by:
  
  hashCode in class AggregatorBase
- equals
  
  public boolean equals(Aggregator other, boolean bySyntax)
  
  Description copied from interface: Aggregator
  
  Consider this 'protected'
- createAccNull
  
  public static Accumulator createAccNull()