org.jahia.services.query

Class QueryServiceImpl

java.lang.Object

org.jahia.services.JahiaService

org.jahia.services.query.QueryService

org.jahia.services.query.QueryServiceImpl

public class QueryServiceImpl
extends QueryService

The default implementation of Jahia's QueryService. Jahia's query service is based on the JCR QueryObjectModelFactory and thus supports all kinds of complex queries specified in JSR-283 (Content Repository for Java� Technology API 2.0) Queries can be created with the API by using the QueryObjectModel. Jahia will also provide a query builder user interface. It is also possible to use SQL-2 and the deprecated XPATH language. As Jahia can plug-in multiple repositories via the universal content hub (UCH), the queries can be converted to other languages, like the EntropySoft connector query language. The query service provides methods to modify and optimize the queries to support and make use of Jahia's internal data model implementation.

Author:

Benjamin Papez

Field Summary

Fields inherited from class org.jahia.services.JahiaService

settingsBean

Method Summary

Modifier and Type	Method and Description
static QueryService	getInstance() Return the unique service instance.
protected org.jahia.services.query.ModificationInfo	getModificationInfo(javax.jcr.query.qom.Source source, javax.jcr.query.qom.Constraint constraint, javax.jcr.query.qom.Ordering[] orderings, javax.jcr.query.qom.Column[] columns, javax.jcr.query.qom.QueryObjectModelFactory qomFactory, JCRSessionWrapper session) We use a QOMTreeVisitor implementation to traverse through the query object model three times.
javax.jcr.ValueFactory	getValueFactory() Entry point to request a ValueFactory instance
protected void	makeModifications(javax.jcr.query.qom.Source source, javax.jcr.query.qom.Constraint constraint, javax.jcr.query.qom.Ordering[] orderings, javax.jcr.query.qom.Column[] columns, org.jahia.services.query.ModificationInfo info, org.apache.jackrabbit.spi.commons.query.qom.QOMTreeVisitor visitor, javax.jcr.query.qom.QueryObjectModelFactory qomFactory)
javax.jcr.query.qom.QueryObjectModel	modifyAndOptimizeQuery(javax.jcr.query.qom.QueryObjectModel qom, javax.jcr.query.qom.QueryObjectModelFactory qomFactory, JCRSessionWrapper session) Modifies the query to adapt to Jahia's internal datamodel implementation, which creates jnt:translation subnodes per locale (language).
javax.jcr.query.qom.QueryObjectModel	modifyAndOptimizeQuery(javax.jcr.query.qom.Source source, javax.jcr.query.qom.Constraint constraint, javax.jcr.query.qom.Ordering[] orderings, javax.jcr.query.qom.Column[] columns, javax.jcr.query.qom.QueryObjectModelFactory qomFactory, JCRSessionWrapper session) Modifies the query to adapt to Jahia's internal datamodel implementation, which creates jnt:translation subnodes per locale (language).
void	start() Initializes the service.
void	stop()

Methods inherited from class org.jahia.services.JahiaService

getSettingsBean, setSettingsBean

Methods inherited from class java.lang.Object

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

Method Detail

getInstance

public static QueryService getInstance()

Return the unique service instance. If the instance does not exist, a new instance is created.

Returns:

The unique service instance.

start

public void start()

Initializes the service.

Specified by:

start in class JahiaService

stop

public void stop()

Specified by:

stop in class JahiaService

modifyAndOptimizeQuery

public javax.jcr.query.qom.QueryObjectModel modifyAndOptimizeQuery(javax.jcr.query.qom.QueryObjectModel qom,
                                                                   javax.jcr.query.qom.QueryObjectModelFactory qomFactory,
                                                                   JCRSessionWrapper session)
                                                            throws javax.jcr.RepositoryException

Description copied from class: QueryService

Modifies the query to adapt to Jahia's internal datamodel implementation, which creates jnt:translation subnodes per locale (language). Furthermore Jahia may make modifications because of performance optimization reasons.

Specified by:

modifyAndOptimizeQuery in class QueryService

Parameters:

qom - the source query object model

qomFactory - query object model factory to use

session - the current JCR session used for the query

Returns:

the modified and optimized query object model

Throws:

javax.jcr.RepositoryException - if the operation fails

modifyAndOptimizeQuery

public javax.jcr.query.qom.QueryObjectModel modifyAndOptimizeQuery(javax.jcr.query.qom.Source source,
                                                                   javax.jcr.query.qom.Constraint constraint,
                                                                   javax.jcr.query.qom.Ordering[] orderings,
                                                                   javax.jcr.query.qom.Column[] columns,
                                                                   javax.jcr.query.qom.QueryObjectModelFactory qomFactory,
                                                                   JCRSessionWrapper session)
                                                            throws javax.jcr.RepositoryException

Description copied from class: QueryService

Modifies the query to adapt to Jahia's internal datamodel implementation, which creates jnt:translation subnodes per locale (language). Furthermore Jahia may make modifications because of performance optimization reasons.

Specified by:

modifyAndOptimizeQuery in class QueryService

Parameters:

source - the QOM Source object to use

constraint - the QOM root constraint object to use

orderings - the QOM ordering objects to use

columns - the QOM column objects to use

qomFactory - query object model factory to use

session - the current JCR session used for the query

Returns:

the created modified and optimized query object model

Throws:

javax.jcr.RepositoryException - if the operation fails

getModificationInfo

protected org.jahia.services.query.ModificationInfo getModificationInfo(javax.jcr.query.qom.Source source,
                                                                        javax.jcr.query.qom.Constraint constraint,
                                                                        javax.jcr.query.qom.Ordering[] orderings,
                                                                        javax.jcr.query.qom.Column[] columns,
                                                                        javax.jcr.query.qom.QueryObjectModelFactory qomFactory,
                                                                        JCRSessionWrapper session)
                                                                 throws javax.jcr.RepositoryException

We use a QOMTreeVisitor implementation to traverse through the query object model three times. The ModificationInfo.mode changes before each iteration from INITIALIZE_MODE to CHECK_FOR_MODIFICATION_MODE and at last MODIFY_MODE, which is only called if modification is necessary.

Throws:

javax.jcr.RepositoryException

makeModifications

protected void makeModifications(javax.jcr.query.qom.Source source,
                                 javax.jcr.query.qom.Constraint constraint,
                                 javax.jcr.query.qom.Ordering[] orderings,
                                 javax.jcr.query.qom.Column[] columns,
                                 org.jahia.services.query.ModificationInfo info,
                                 org.apache.jackrabbit.spi.commons.query.qom.QOMTreeVisitor visitor,
                                 javax.jcr.query.qom.QueryObjectModelFactory qomFactory)
                          throws javax.jcr.RepositoryException

Throws:

javax.jcr.RepositoryException

getValueFactory

public javax.jcr.ValueFactory getValueFactory()

Description copied from class: QueryService

Entry point to request a ValueFactory instance

Specified by:

getValueFactory in class QueryService

Returns:

ValueFactory