it.unimi.dico.islab.idbs2.kc.session

Class KCManager

java.lang.Object

it.unimi.dico.islab.idbs2.kc.session.KCManager

public class KCManager
extends Object

Manages object saving and querying for KnowledgeChunk wrapper. This class contains most used interrogations (such as getKnowledgeChunkById and methods for saving an object of this class.

IMPORTANT: this class has no public constructor. A singleton instance of this class is contained in KCSessionManager class

Author:

Vegeziel

Method Summary

Methods

Modifier and Type	Method and Description
List<KnowledgeChunk>	getAllProperties() Used to load a list of all properties (KnowledgeChunk of type P) in the connected database.
protected static KCManager	getKCManager()
KnowledgeChunk	getKnowledgeChunkById(String id) Used to load a KnowledgeChunk instance from the database.
HashSet<KnowledgeChunk>	getKnowledgeChunksByClass(String classId) Fetch all KnowledgeChunks having classId as a declared class.
HashSet<KnowledgeChunk>	getKnowledgeChunksWithIdLike(String likeExpr) Fetch all the objects of type KnowledgeChunk having an identifier matching the expression likeExpr.
void	saveOrUpdate(KnowledgeChunk kc) Give persistence to the given KnowledgeChunk object using associated Hibernate mappings.

Methods inherited from class java.lang.Object

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

Method Detail

getKCManager

protected static KCManager getKCManager()

getKnowledgeChunkById

public KnowledgeChunk getKnowledgeChunkById(String id)

Used to load a KnowledgeChunk instance from the database. This method uses the internal Session Factory of this class (different from the one obtained calling the getSessionFactory method.

Parameters:

id - the identifier of a Knowledge Chunk.

Returns:

the Knowledge Chunk having id as primary key value.

getKnowledgeChunksWithIdLike

public HashSet<KnowledgeChunk> getKnowledgeChunksWithIdLike(String likeExpr)

Fetch all the objects of type KnowledgeChunk having an identifier matching the expression likeExpr.

Parameters:

likeExpr - an expression with jolly characters of the SQL Standard LIKE clause.

Returns:

a set containing all found KnowledgeChunks

getAllProperties

public List<KnowledgeChunk> getAllProperties()

Used to load a list of all properties (KnowledgeChunk of type P) in the connected database. This method uses the internal Session Factory of this class (different from the one obtained calling the getSessionFactory method.

Returns:

the list of all KnowledgeChunks of type P.

getKnowledgeChunksByClass

public HashSet<KnowledgeChunk> getKnowledgeChunksByClass(String classId)

Fetch all KnowledgeChunks having classId as a declared class. N.B.: Doesn't work if negated classes are present!! Work in progress...

Parameters:

classId - the identifier of the KnowledgeChunk of type C that represents the class of the returned KnowledgeChunks.

Returns:

a set containing all KnowledgeChunks having classId as asserted class.

saveOrUpdate

public void saveOrUpdate(KnowledgeChunk kc)

Give persistence to the given KnowledgeChunk object using associated Hibernate mappings.

This method executes the saveOrUpdate method of the Hibernate Session using internal Session Factory of KCSessionManager. As the KnowledgeChunk is the main class of this package, by saving this object a cascade save is started for all connected objects (predicates and all referred kcs, types, terms, documents and documentextractions).