org.carrot2.input.aggregator
Class AggregatorInputComponent

java.lang.Object
  org.carrot2.core.LocalComponentBase
      org.carrot2.core.LocalInputComponentBase
          org.carrot2.input.aggregator.AggregatorInputComponent

All Implemented Interfaces:

RawDocumentsProducer, LocalComponent, LocalInputComponent, ResultsCollector

public class AggregatorInputComponent
extends LocalInputComponentBase
implements ResultsCollector, RawDocumentsProducer

This is an input component that aggregates results from a number of other input components. In the constructor you can specify an array of factories of input components to be aggregated. Optionally, you can set the maximum amount of time the aggregator component will wait for all the individual inputs to deliver the results. For a usage example, see AggregatorInputExample.

Limitations:

• For the time being, this component does not perform query translation. This means that you might be getting strange results in case of advanced or non-standard query syntax.

This component was donated to the Carrot2 project by deepVertical.

Author:

Stanislaw Osinski

See Also:

AggregatorInputExample

Field Summary

static int

DEFAULT_INPUT_TIMEOUT The default input timeout (in miliseconds, 10 seconds).

Fields inherited from class org.carrot2.core.LocalInputComponentBase

next

Fields inherited from interface org.carrot2.core.clustering.RawDocumentsProducer

PARAM_ORIGINAL_RAW_CLUSTERS, PROPERTY_CATID

Fields inherited from interface org.carrot2.core.LocalInputComponent

PARAM_QUERY, PARAM_REQUESTED_RESULTS, PARAM_START_AT, PARAM_TOTAL_MATCHING_DOCUMENTS

Constructor Summary

AggregatorInputComponent(AggregatorInput[] inputs)
Creates the aggregator input component.

AggregatorInputComponent(AggregatorInput[] inputs, int timeout)
Creates the aggregator input component.

Method Summary

void	addResults(List results, String inputId)
void	endProcessing() The default implementation invokes endProcessing() method on the successor component.
void	flushResources() The default implementation invokes flushResources() method on the successor component.
Set	getComponentCapabilities() Provides an implementation that has no capabilities (an empty set).
String	getName() The default implementation returning null.
Set	getRequiredSuccessorCapabilities() Provides an implementation that requires no capabilities of the successor component.
void	init(LocalControllerContext context) Provides an empty implementation.
void	processingErrorOccurred() The default implementation invokes processingErrorOccurred() method on the successor component.
void	setNext(LocalComponent next) The default implementation sets the LocalInputComponentBase.next field and verifies the contract in LocalFilterComponent.setNext(LocalComponent)
void	setQuery(String query) Sets the query for the current request.
void	startProcessing(RequestContext requestContext) The default implementation invokes protected LocalInputComponentBase.validate() method first to verify preconditions.

Methods inherited from class org.carrot2.core.LocalInputComponentBase

getRequestedResults, validate

Methods inherited from class org.carrot2.core.LocalComponentBase

getDescription, getIntFromRequestContext, getProperty, getRequiredPredecessorCapabilities, setProperty, toSet, toSet, toSet

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.carrot2.core.LocalComponent

getDescription, getRequiredPredecessorCapabilities, setProperty

Field Detail

DEFAULT_INPUT_TIMEOUT

public static final int DEFAULT_INPUT_TIMEOUT

The default input timeout (in miliseconds, 10 seconds).

See Also:

Constant Field Values

Constructor Detail

AggregatorInputComponent

public AggregatorInputComponent(AggregatorInput[] inputs)

Creates the aggregator input component.

Parameters:

inputs - an array of AggregatorInputs describing the document sources to be aggregated

AggregatorInputComponent

public AggregatorInputComponent(AggregatorInput[] inputs,
                                int timeout)

Creates the aggregator input component.

Parameters:

inputs - an array of AggregatorInputs describing the document sources to be aggregated

timeout - the maximum amount of time the aggregator component will wait for all the individual inputs to deliver the results

Method Detail

getComponentCapabilities

public Set getComponentCapabilities()

Description copied from class: LocalComponentBase

Provides an implementation that has no capabilities (an empty set).

Specified by:

getComponentCapabilities in interface LocalComponent

Overrides:

getComponentCapabilities in class LocalComponentBase

Returns:

A Setobject with capabilities. The object returned may be empty, but should never be null.

getRequiredSuccessorCapabilities

public Set getRequiredSuccessorCapabilities()

Description copied from class: LocalComponentBase

Provides an implementation that requires no capabilities of the successor component.

Specified by:

getRequiredSuccessorCapabilities in interface LocalComponent

Overrides:

getRequiredSuccessorCapabilities in class LocalComponentBase

Returns:

A Setobject with capabilities. The object returned may be empty, but should never be null.

setNext

public void setNext(LocalComponent next)

Description copied from class: LocalInputComponentBase

The default implementation sets the LocalInputComponentBase.next field and verifies the contract in LocalFilterComponent.setNext(LocalComponent)

Specified by:

setNext in interface LocalInputComponent

Overrides:

setNext in class LocalInputComponentBase

Parameters:

next - A reference to an instance of LocalComponent that is the successor component in a processing chain assembled for the execution of a single query.

endProcessing

public void endProcessing()
                   throws ProcessingException

Description copied from class: LocalInputComponentBase

The default implementation invokes endProcessing() method on the successor component.

Specified by:

endProcessing in interface LocalComponent

Overrides:

endProcessing in class LocalInputComponentBase

Throws:

ProcessingException - Thrown if the component encountered a problem in processing the query. May also be thrown from a chained successor component. It is allowed to throw an exception and not invoke endProcessing() method on subsequent components. In such case, all components will receive a LocalComponent.processingErrorOccurred()call.

flushResources

public void flushResources()

Description copied from class: LocalInputComponentBase

The default implementation invokes flushResources() method on the successor component.

Specified by:

flushResources in interface LocalComponent

Overrides:

flushResources in class LocalInputComponentBase

processingErrorOccurred

public void processingErrorOccurred()

Description copied from class: LocalInputComponentBase

The default implementation invokes processingErrorOccurred() method on the successor component.

Specified by:

processingErrorOccurred in interface LocalComponent

Overrides:

processingErrorOccurred in class LocalInputComponentBase

startProcessing

public void startProcessing(RequestContext requestContext)
                     throws ProcessingException

Description copied from class: LocalInputComponentBase

The default implementation invokes protected LocalInputComponentBase.validate() method first to verify preconditions. Then it invokes startProcessing(requestContext) method on the successor component.

Specified by:

startProcessing in interface LocalComponent

Overrides:

startProcessing in class LocalInputComponentBase

Parameters:

requestContext - A RequestContextinterface instance passed by the container processing the query. The context may be used to retrieve parameters associated with the query (see RequestContext.getRequestParameters() method).

Throws:

ProcessingException - Thrown if the component encountered a problem in processing the query. May also be thrown from a chained successor component.

addResults

public void addResults(List results,
                       String inputId)

Specified by:

addResults in interface ResultsCollector

init

public void init(LocalControllerContext context)
          throws InstantiationException

Description copied from class: LocalComponentBase

Provides an empty implementation.

Specified by:

init in interface LocalComponent

Overrides:

init in class LocalComponentBase

Parameters:

context - A controller context instance.

Throws:

InstantiationException - Thrown if the component is unable to properly initialize and should not be used to process queries.

See Also:

LocalComponent.init(LocalControllerContext)

setQuery

public void setQuery(String query)

Description copied from interface: LocalInputComponent

Sets the query for the current request. The format of the query depends on the component used.

Specified by:

setQuery in interface LocalInputComponent

Parameters:

query - A String with the query.

getName

public String getName()

Description copied from class: LocalComponentBase

The default implementation returning null. In concrete implementations override this method to provide the appropriate name.

Specified by:

getName in interface LocalComponent

Overrides:

getName in class LocalComponentBase

Returns:

null name