prajna.entity

Class CompositeExtractor

java.lang.Object

prajna.entity.EntityExtractor

prajna.entity.CompositeExtractor

All Implemented Interfaces:

EntityVerifier, RecordReasoner

public class CompositeExtractor
extends EntityExtractor
implements EntityVerifier

The composite entity extractor uses multiple entity extractors to determine the entities and their types using a consensus approach. It also uses optional entity verifiers to verify entities.

Author:

Edward Swing

Constructor Summary

Constructors

Constructor and Description
CompositeExtractor()

Method Summary

Methods

Modifier and Type	Method and Description
void	addExtractor(EntityExtractor extractor) Add an extractor to the set of entity extractors used by this composite extractor.
void	addExtractor(EntityExtractor extractor, int weight) Add an extractor to the set of entity extractors used by this composite extractor, along with a weight.
void	addVerifier(EntityVerifier verifier) Add an entity verifier to the set of entity verifiers used by this composite extractor.
void	addVerifier(EntityVerifier verifier, int weight) Add an entity verifier to the set of entity verifiers used by this composite extractor, using the specified weight
EntityType	determineType(java.lang.String term) Determine the entity type for a particular term.
protected void	extractEntities(java.lang.String text, java.util.Map<java.lang.String,EntityTag> tokenMap) Extract the entities from the text provided.
java.util.Map<java.lang.String,java.lang.String>	extractEntityRawTypes(java.lang.String text) Retrieve the entities and the raw types for this entity extractor.
java.util.Set<EntityExtractor>	getExtractors() Get the set of extractors used by this composite extractor
java.util.Set<EntityType>	getSupportedTypes() Return the list of types this verifier can verify.
java.util.Set<EntityVerifier>	getVerifiers() Get the set of verifiers used by this composite extractor
java.lang.String	normalize(java.lang.String term, EntityType type) Get a normalized form for this entity and type.
void	setDocumentDate(java.util.Date date) Set the date to be used for documents.
boolean	verifyType(java.lang.String term, EntityType type) Verify that the term matches the type.

Methods inherited from class prajna.entity.EntityExtractor

addTagFieldMapping, addTextField, augmentRecord, extract, extract, extract, extract, getDefaultTagField, getModel, isDebug, setDebug, setDefaultTagField, setModel

Methods inherited from class java.lang.Object

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

Methods inherited from interface prajna.entity.EntityVerifier

getModel, setModel

Constructor Detail

CompositeExtractor

public CompositeExtractor()

Method Detail

addExtractor

public void addExtractor(EntityExtractor extractor)

Add an extractor to the set of entity extractors used by this composite extractor. The extractor is assigned the default weight of 500.

Parameters:

extractor - the new entity extractor

addExtractor

public void addExtractor(EntityExtractor extractor,
                int weight)

Add an extractor to the set of entity extractors used by this composite extractor, along with a weight. The higher the weight, the more the extractor will be when comparing results. Weights are nominally in the range 1-1000, with 1000 being the highest weight.

Parameters:

extractor - the new entity extractor

weight - the weight for the extractor

addVerifier

public void addVerifier(EntityVerifier verifier)

Add an entity verifier to the set of entity verifiers used by this composite extractor. The weight for the verifier is set to 500.

Parameters:

verifier - the new entity verifier

addVerifier

public void addVerifier(EntityVerifier verifier,
               int weight)

Add an entity verifier to the set of entity verifiers used by this composite extractor, using the specified weight

Parameters:

verifier - the new entity verifier

weight - the weight for the verifier

determineType

public EntityType determineType(java.lang.String term)

Determine the entity type for a particular term. This method could be used to identify a term that is originally of type UNKNOWN. If the verifier can verify that the term is an entity, but not its type, then it should return EntityType.UNKNOWN. If the term is not an entity recognized by this verifier, it should return null.

Specified by:

determineType in interface EntityVerifier

Parameters:

term - the term to check. This is the extracted entity

Returns:

the entity type for the term.

extractEntities

protected void extractEntities(java.lang.String text,
                   java.util.Map<java.lang.String,EntityTag> tokenMap)

Extract the entities from the text provided. This method calls extractEntityRawTypes(), then uses an internal map to map the raw entity types to EntityType objects.

Specified by:

extractEntities in class EntityExtractor

Parameters:

text - the text to extract

tokenMap - the map to contain the tokens in.

extractEntityRawTypes

public java.util.Map<java.lang.String,java.lang.String> extractEntityRawTypes(java.lang.String text)

Retrieve the entities and the raw types for this entity extractor. This method runs the extraction process on the text, and generates a map that identifies each entity with a type. The types returned from this method are not normalized, and dependent on the entity extractor implementation. This method returns the set of raw tags for each entity, separated by commas.

Specified by:

extractEntityRawTypes in class EntityExtractor

Parameters:

text - the text to parse for entities

Returns:

the raw entity types

getExtractors

public java.util.Set<EntityExtractor> getExtractors()

Get the set of extractors used by this composite extractor

Returns:

the set of extractors used by this composite extractor

getSupportedTypes

public java.util.Set<EntityType> getSupportedTypes()

Return the list of types this verifier can verify. This method returns the union of the component verifiers

Specified by:

getSupportedTypes in interface EntityVerifier

Returns:

the set of types supported.

getVerifiers

public java.util.Set<EntityVerifier> getVerifiers()

Get the set of verifiers used by this composite extractor

Returns:

the set of verifiers used by this composite extractor

normalize

public java.lang.String normalize(java.lang.String term,
                         EntityType type)

Get a normalized form for this entity and type. This method ensures that any entity of the specified type will conform to a particular format, or resolve spelling differences, etc. If the term is not supported by this verifier, or if the verifier cannot normalize the term, null is returned. This implementation simply checks all of its child verifiers to normalize the term.

Specified by:

normalize in interface EntityVerifier

Parameters:

term - the term to normalize

type - the entity type

Returns:

a normalized string

setDocumentDate

public void setDocumentDate(java.util.Date date)

Set the date to be used for documents. By default, the current time is used. This call allows any DateTime verifiers to identify the correct date from a relative time stamp

Parameters:

date - the date for the document to be parsed

verifyType

public boolean verifyType(java.lang.String term,
                 EntityType type)

Verify that the term matches the type. If the verifier cannot verify the term, or cannot positively identify it as the specified type, it should return false

Specified by:

verifyType in interface EntityVerifier

Parameters:

term - the term to check. This is the extracted entity

type - the type to check against.

Returns:

true if and only if the verifier can positively determine that the term matches the type, false otherwise.