org.universAAL.middleware.service
Class AggregatingFilterFactory

java.lang.Object
  org.universAAL.middleware.service.AggregatingFilterFactory

public class AggregatingFilterFactory
extends Object

A Factory to create different kinds of AggregatingFilter. These filters can be given to a ServiceRequest to influence the selection of services during matchmaking or their output when processing the result from services after they have been called and before the result is given to the ServiceCaller. AggregatingFilters are only evaluated if there is more than one service that match a ServiceRequest. There are basically two types of filter:

• Service Selection:

  The service selection filters restrict the number of service calls to calling only one service even if more than one service would match.

  If there is only one filter with the filtering function AggregationFunction.oneOf, then one of the available services is selected randomly. If a filter with one of the other aggregation functions is set, then the service with a matching non-functional parameter is called (see description of the appropriate methods).

  Service selection filters are given to a service request via ServiceRequest.addAggregatingFilter(AggregatingFilter). Creation is done with one of the methods createServiceSelectionFilter(), createServiceSelectionFilter(MinMax, String), or createServiceSelectionFilter(MinMax, String, AbsLocation).

• Output Aggregation:

  The output aggregation filters aggregate the output coming from several service calls.

  These filters can be used, for example, when your request requires two outputs: a location and the brightness in that location, but you don't want to receive a whole list of all available data but just the one location with the maximum brightness.

  Output aggregation filters are given to a service request via ServiceRequest.addAggregatingOutputBinding(org.universAAL.middleware.service.owls.process.ProcessOutput, AggregatingFilter) . Creation is done with one of the methods createOutputAggregationFilter(MinMax) or createOutputAggregationFilter(MinMax, AbsLocation).

Author:

Carsten Stocklöw

Nested Class Summary

static class

AggregatingFilterFactory.MinMax Definition of the type of the aggregation functions: either a minimum value or a maximum value.

Constructor Summary

AggregatingFilterFactory()

Method Summary

static AggregatingFilter	createOutputAggregationFilter(AggregatingFilterFactory.MinMax type) Creates an output aggregation filter.
static AggregatingFilter	createOutputAggregationFilter(AggregatingFilterFactory.MinMax type, AbsLocation location) Creates an output aggregation filter.
static AggregatingFilter	createServiceSelectionFilter() Create a service selection filter that selects one service randomly.
static AggregatingFilter	createServiceSelectionFilter(AggregatingFilterFactory.MinMax type, String nonFunctionalParamPropURI) Creates a service selection filter that evaluates a non-functional parameter that is not related to a location.
static AggregatingFilter	createServiceSelectionFilter(AggregatingFilterFactory.MinMax type, String nonFunctionalParamPropURI, AbsLocation location) Creates a service selection filter that evaluates a non-functional parameter that is related to a location.

Methods inherited from class java.lang.Object

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

Constructor Detail

AggregatingFilterFactory

public AggregatingFilterFactory()

Method Detail

createServiceSelectionFilter

public static AggregatingFilter createServiceSelectionFilter()

Create a service selection filter that selects one service randomly. The aggregation function is AggregationFunction.oneOf. This filter is ignored if another filter with a different function is added to the service request.

Returns:

a filter with a AggregationFunction.oneOf function.

createServiceSelectionFilter

public static AggregatingFilter createServiceSelectionFilter(AggregatingFilterFactory.MinMax type,
                                                             String nonFunctionalParamPropURI)

Creates a service selection filter that evaluates a non-functional parameter that is not related to a location.

Parameters:

type - determines whether either the service with the minimum value or the maximum value of the parameter is called.

nonFunctionalParamPropURI - the URI of the non-functional parameter. Typical values are: ServiceProfile.PROP_uAAL_MIN_QOS_RATING, ServiceProfile.PROP_uAAL_AVERAGE_QOS_RATING, ServiceProfile.PROP_uAAL_MAX_QOS_RATING, ServiceProfile.PROP_uAAL_MIN_RESPONSE_TIME, ServiceProfile.PROP_uAAL_AVERAGE_RESPONSE_TIME, ServiceProfile.PROP_uAAL_MAX_RESPONSE_TIME, ServiceProfile.PROP_uAAL_NUMBER_OF_QOS_RATINGS, ServiceProfile.PROP_uAAL_NUMBER_OF_RESPONSE_TIME_MEASUREMENTS , ServiceProfile.PROP_uAAL_RESPONSE_TIMEOUT.

Returns:

a new aggregating filter.

createServiceSelectionFilter

public static AggregatingFilter createServiceSelectionFilter(AggregatingFilterFactory.MinMax type,
                                                             String nonFunctionalParamPropURI,
                                                             AbsLocation location)

Creates a service selection filter that evaluates a non-functional parameter that is related to a location.

Parameters:

type - determines whether either the service with the minimum value or the maximum value of the parameter is called.

nonFunctionalParamPropURI - ServiceProfile.PROP_uAAL_HOST_LOCATION, ServiceProfile.PROP_uAAL_SPATIAL_COVERAGE.

location - the location that is referenced by the parameter.

Returns:

a new aggregating filter.

createOutputAggregationFilter

public static AggregatingFilter createOutputAggregationFilter(AggregatingFilterFactory.MinMax type)

Creates an output aggregation filter.

Parameters:

type - determines whether the output with the minimum value or the maximum value is used.

Returns:

a new aggregating filter.

createOutputAggregationFilter

public static AggregatingFilter createOutputAggregationFilter(AggregatingFilterFactory.MinMax type,
                                                              AbsLocation location)

Creates an output aggregation filter.

Parameters:

type - determines whether the output with the minimum value or the maximum value is used.

location - the location that is referenced by the parameter.

Returns:

a new aggregating filter.