org.apache.jena.arq.querybuilder.handlers

Class AggregationHandler

java.lang.Object

org.apache.jena.arq.querybuilder.handlers.AggregationHandler

All Implemented Interfaces:

Handler

public class AggregationHandler
extends Object
implements Handler

Class to handle manipulation the aggregation variables in the query.

Constructor Summary

Constructors

Constructor and Description
AggregationHandler(Query query) Constructor.

Method Summary

Modifier and Type	Method and Description
void	add(Expr expr, Var var) Add and expression aggregator and variable to the mapping.
AggregationHandler	addAll(AggregationHandler handler) Add all the aggregations from the other handler.
void	build() Called by the build process for this handler to perform any adjustments to the query before the build completes.
Query	getQuery() Get the query we are executing against.
void	setVars(Map<Var,Node> values) Set the values for variables managed by the handler implementation.

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregationHandler

public AggregationHandler(Query query)

Constructor.

Parameters:

query - the query to handle.

Method Detail

addAll

public AggregationHandler addAll(AggregationHandler handler)

Add all the aggregations from the other handler.

Parameters:

handler - The other handler.

Returns:

This handler for chaining.

getQuery

public Query getQuery()

Get the query we are executing against.

Returns:

the query.

setVars

public void setVars(Map<Var,Node> values)

Description copied from interface: Handler

Set the values for variables managed by the handler implementation. This method is called by the builder to set values handled by this Handler implementation.

Specified by:

setVars in interface Handler

Parameters:

values - The map of variable to node value.

build

public void build()

Description copied from interface: Handler

Called by the build process for this handler to perform any adjustments to the query before the build completes. The adjustments are made after setVars() has been called.

Specified by:

build in interface Handler

add

public void add(Expr expr,
                Var var)

Add and expression aggregator and variable to the mapping. if the expr parameter is not an instance of ExprAggregator then no action is taken.

Parameters:

expr - The expression to add.

var - The variable that it is bound to.