it.unimi.dico.islab.idbs2.kc

Class KnowledgeChunk

java.lang.Object

it.unimi.dico.islab.idbs2.kc.KnowledgeChunk

public class KnowledgeChunk
extends Object

Main class of the kc framework, representation of a knowledge chunk. A kc is unit of knowledge, the representation of an object, type or property of the context of interest. It is composed by a list of types, a terminological equipment (a list of terms with associated frequency value and relevance value), a set of predicates (i.e. a set of property paths with associated object/value), a type (i.e. {C, P, I}, as Class, Property or Instance) and a connected Document, source of the extraction process.

The following image shows the relations between the fields of this object and the fields of the wrapped database table (fields with the same color represents a mapping between relational schema and the corresponding object).

This class also supplies methods for Hibernate database wrapper management.

Author:

Vegeziel

See Also:

Document, Predicate, Term, Type

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	KnowledgeChunk() Empty constructor needed for Hibernate compatibility.
	KnowledgeChunk(String id) Generates new empty KnowledgeChunk given an identifier.

Method Summary

Methods

Modifier and Type	Method and Description
void	addDocument(Document doc) Adds a source document to this KnowledgeChunk instance.
Predicate	addLink(KnowledgeChunk p1, KnowledgeChunk pn, KnowledgeChunk valueKc, String value, int pathLength, String valueType, int valueLength) Deprecated. This method has been replaced with the more comprehensible addPredicate.
Predicate	addPredicate(KnowledgeChunk p1, KnowledgeChunk pn, KnowledgeChunk valueKc, String value, int pathLength, String valueType, int valueLength) Adds a property path to this KnowledgeChunk object.
Predicate	addPredicate(KnowledgeChunk property, KnowledgeChunk valueKc, String value, int pathLength, String valueType, int valueLength) Shortcut for the addPredicate method when creating predicates with p1 = pn.
Term	addTerm(String value, Double relevance, Integer frequency) Add a keyword to this KnowledgeChunk specifying its relevance and frequency.
Type	addType(KnowledgeChunk type) Overloaded method of the addType(type, isType) method.
Type	addType(KnowledgeChunk type, boolean isType) Add a class (represented by a KnowledgeChunk instance) to this KnowledgeChunk specifying if is an asserted or excluded type.
boolean	equals(Object o)
Set<Document>	getDocuments() Retrieves all the documents which this kc belongs to.
Set<DocumentExtraction>	getExtractedFrom() Getter for the list of document where this kc belongs.
Boolean	getGlobal()
String	getId() Getter for the identifier of this class.
Set<Predicate>	getLinks() Getter for the set of predicates having this node as a belongKc.
String	getName() Getter for the name representation of this KnowledgeChunk.
Term	getTerm(String value) Returns the Term having the given value or null if such Term doesn't exist.
String	getTermEquipmentFlat() Getter for the term equipment flat representation.
Set<String>	getTermEquipmentPlain() Returns the full term equipment of this object as a Set of Strings.
HashSet<Term>	getTermEquipmentWrapped() Returns the full term equipment of this object as a Set of Term objects.
Character	getType() Getter for the type of this object.
Type	getType(KnowledgeChunk type) Returns the Type having the given type or null if such Type doesn't exist.
Type	getType(String type) Returns the Type having the given type id or null if such Type doesn't exist.
Set<String>	getTypesPlain() Getter for the set of all types identifiers of this kc.
Set<Type>	getTypesWrapped() Getter for the set of all types of this kc.
int	hashCode() The hash code for this class is the hash code of its identifier (considered as a string value).
Term	removeTerm(String t) Removes the keyword t from this KnowledgeChunk and returns the removed Term wrapper.
Term	removeTerm(Term t) Remove the term with value t.getValue() from this kc and returns the removed instance of Term.
Type	removeType(KnowledgeChunk type) Removes the type type from this KnowledgeChunk.
Type	removeType(String type) Removes the type represented by the id type from this KnowledgeChunk.
void	setGlobal(Boolean global)
void	setName(String name) Setter for the name representation of this KnowledgeChunk.
void	setTermEquipmentFlat(String terEq) Setter for the term equipment flat representation.
void	setType(Character type) Setter for the type of this object.
String	toString() Give a textual representation of this object in form of its identifier.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

KnowledgeChunk

public KnowledgeChunk(String id)

Generates new empty KnowledgeChunk given an identifier.

N.B.: A new instance of KnowledgeChunk will be in a detached state (see Hibernate reference manual for more details about object states) until an explicit request (like a save operation). If a KnowledgeChunk with the same primary key will already be present on the wrapped database, an exception will be thrown while trying to save this new instance. In order to reload an existing KnowledgeChunk use KCManager.getKnowledgeChunkById(String)

Parameters:

id - string identifier for the new KnowledgeChunk

See Also:

KCSessionManager.kcm

KnowledgeChunk

protected KnowledgeChunk()

Empty constructor needed for Hibernate compatibility. Direct usage is discouraged, use KnowledgeChunk(String id) instead.

See Also:

id

Method Detail

addType

public Type addType(KnowledgeChunk type)

Overloaded method of the addType(type, isType) method. In this version isType is assumed true.

Parameters:

type - a KnowledgeChunk to be added as a type for this object. If type is a null value it will be ignored raising a warning message.

Returns:

the created Type, already associated with this KnowledgeChunk

addType

public Type addType(KnowledgeChunk type,
           boolean isType)

Add a class (represented by a KnowledgeChunk instance) to this KnowledgeChunk specifying if is an asserted or excluded type.

Parameters:

type - a KnowledgeChunk to be added as a type (or as a "is not type") for this object. If type is a null value it will be ignored raising a warning message.

isType -

• true: type is a declared class of this KnowledgeChunk
• false: type is a denied class of this KnowledgeChunk

Returns:

the created Type, already associated with this KnowledgeChunk

removeType

public Type removeType(String type)

Removes the type represented by the id type from this KnowledgeChunk.

Parameters:

type - the type (a String value representing the identifier of the type) to be removed. If type is a null, a void value or it doesn't exists in this kc it will be ignored raising a warning message.

Returns:

null if type was not associated to this kc, the removed type (class Type) otherwise.

removeType

public Type removeType(KnowledgeChunk type)

Removes the type type from this KnowledgeChunk.

Parameters:

type - the type (a KnowledgeChunk of type 'C') to be removed. If type is a null value or it doesn't exists in this kc it will be ignored raising a warning message.

Returns:

null if type was not associated to this kc, the removed type (class Type) otherwise.

getType

public Type getType(String type)

Returns the Type having the given type id or null if such Type doesn't exist.

Parameters:

type - the type name of the required Type.

Returns:

the Type wrapper (class Type) associated with the id type.

getType

public Type getType(KnowledgeChunk type)

Returns the Type having the given type or null if such Type doesn't exist.

Parameters:

type - the KnowledgeChunk of type 'C' of the required Type.

Returns:

the Type wrapper (class Type) associated with the class type.

getTypesPlain

public Set<String> getTypesPlain()

Getter for the set of all types identifiers of this kc.

Returns:

the set of all types of this kc as a set of Strings.

getTypesWrapped

public Set<Type> getTypesWrapped()

Getter for the set of all types of this kc.

Returns:

the set of all types of this kc.

See Also:

Type

addTerm

public Term addTerm(String value,
           Double relevance,
           Integer frequency)

Add a keyword to this KnowledgeChunk specifying its relevance and frequency.

Parameters:

value - the keyword to be added. If value is a null value it will be ignored raising a warning message.

relevance - the relevance of the added keyword for this KnowledgeChunk.S

frequency - the frequency of the added keyword in the terminological equipment of this KnowledgeChunk, expressed as the number of its occurrences.

Returns:

the created Term, already associated with this KnowledgeChunk

removeTerm

public Term removeTerm(String t)

Removes the keyword t from this KnowledgeChunk and returns the removed Term wrapper.

Parameters:

t - the keyword to be removed. If t is a null or a void value it will be ignored raising a warning message.

Returns:

the removed Term instance.

removeTerm

public Term removeTerm(Term t)

Remove the term with value t.getValue() from this kc and returns the removed instance of Term. If such a term does not exist returns null and prints a warning message.

Parameters:

t - the term with the value that should be removed from the terminological equipment of this KnowledgeChunk.

Returns:

null if there is no term in this kc with the sema value of t, the removed term otherwise.

getTerm

public Term getTerm(String value)

Returns the Term having the given value or null if such Term doesn't exist.

Parameters:

value - the value of the required Term.

Returns:

the term wrapper (class Term) associated with the keyword value.

addLink

public Predicate addLink(KnowledgeChunk p1,
                KnowledgeChunk pn,
                KnowledgeChunk valueKc,
                String value,
                int pathLength,
                String valueType,
                int valueLength)

Deprecated. This method has been replaced with the more comprehensible addPredicate.

Adds a property path to this KnowledgeChunk object. The property path is represented by a Predicate instance starting from the current object (that will be the belongKc value).

Parameters:

p1 - a KnowledgeChunk representing the first edge (property) in the path.

pn - a KnowledgeChunk representing the last edge (property) in the path.

valueKc - a KnowledgeChunk representing the final object of the property path.

value - a literal that is the value of the last object of the path.

pathLength - the number of edges in the path.

valueType - string representation for the data type of the value field.

valueLength - length of the value field, materialized for efficiency reasons.

Returns:

the generated Predicate

See Also:

Predicate, addPredicate(KnowledgeChunk, KnowledgeChunk, KnowledgeChunk, String, int, String, int)

addPredicate

public Predicate addPredicate(KnowledgeChunk p1,
                     KnowledgeChunk pn,
                     KnowledgeChunk valueKc,
                     String value,
                     int pathLength,
                     String valueType,
                     int valueLength)

Adds a property path to this KnowledgeChunk object. The property path is represented by a Predicate instance starting from the current object (that will be the belongKc value).

Parameters:

p1 - a KnowledgeChunk representing the first edge (property) in the path.

pn - a KnowledgeChunk representing the last edge (property) in the path.

valueKc - a KnowledgeChunk representing the final object of the property path.

value - a literal that is the value of the last object of the path.

pathLength - the number of edges in the path.

valueType - string representation for the data type of the value field.

valueLength - length of the value field, materialized for efficiency reasons.

Returns:

the generated Predicate

See Also:

Predicate

addPredicate

public Predicate addPredicate(KnowledgeChunk property,
                     KnowledgeChunk valueKc,
                     String value,
                     int pathLength,
                     String valueType,
                     int valueLength)

Shortcut for the addPredicate method when creating predicates with p1 = pn.

Parameters:

property - The KnowledgeChunk that will represent p1 AND pn.

valueKc - a KnowledgeChunk representing the final object of the property path.

value - a literal that is the value of the last object of the path.

pathLength - the number of edges in the path.

valueType - string representation for the data type of the value field.

valueLength - length of the value field, materialized for efficiency reasons.

Returns:

the generated Predicate

See Also:

addPredicate(KnowledgeChunk, KnowledgeChunk, KnowledgeChunk, String, int, String, int)

addDocument

public void addDocument(Document doc)

Adds a source document to this KnowledgeChunk instance.

Parameters:

doc - the document to be added

getDocuments

public Set<Document> getDocuments()

Retrieves all the documents which this kc belongs to.

Returns:

the documents which this kc belongs to.

getTermEquipmentWrapped

public HashSet<Term> getTermEquipmentWrapped()

Returns the full term equipment of this object as a Set of Term objects.

Returns:

the set of all terms belonging to the term equipment of this kc, wrapped in a special class Type.

See Also:

Term

getTermEquipmentPlain

public Set<String> getTermEquipmentPlain()

Returns the full term equipment of this object as a Set of Strings. objects.

Returns:

the set of all terms belonging to the term equipment of this kc.

See Also:

Term

toString

public String toString()

Give a textual representation of this object in form of its identifier.

Overrides:

toString in class Object

Returns:

a String representing the identifier of this object.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

The hash code for this class is the hash code of its identifier (considered as a string value).

Overrides:

hashCode in class Object

getId

public String getId()

Getter for the identifier of this class.

Returns:

the string identifier of this KnowledgeChunk

getName

public String getName()

Getter for the name representation of this KnowledgeChunk. Usually the name of the represented object.

Returns:

the name of this KnowledgeChunk.

setName

public void setName(String name)

Setter for the name representation of this KnowledgeChunk.

Parameters:

name - the name of this KnowledgeChunk.

setGlobal

public void setGlobal(Boolean global)

getGlobal

public Boolean getGlobal()

getLinks

public Set<Predicate> getLinks()

Getter for the set of predicates having this node as a belongKc.

Returns:

a set of predicates.

getExtractedFrom

public Set<DocumentExtraction> getExtractedFrom()

Getter for the list of document where this kc belongs.

Returns:

a set of objects representing the extraction of this kc from a document.

setType

public void setType(Character type)

Setter for the type of this object. It could be

• P: property
• I: instance
• T: type/class

Parameters:

type - a character representing the type of this object.

getType

public Character getType()

Getter for the type of this object. It could be

• P: property
• I: instance
• T: type/class

Returns:

a character representing the type of this object.

setTermEquipmentFlat

public void setTermEquipmentFlat(String terEq)

Setter for the term equipment flat representation. This is a list of comma separated words.

Parameters:

terEq - the comma separated list of words representing the term equipment of this object.

getTermEquipmentFlat

public String getTermEquipmentFlat()

Getter for the term equipment flat representation. This is a list of comma separated words.

Returns:

terEq the comma separated list of words representing the term equipment of this object.