com.github.anno4j.querying

Class QueryService

java.lang.Object

com.github.anno4j.querying.QueryService

public class QueryService
extends Object

The QueryService allows to query triple stores by using criteria. Furthermore this is provided by simple classes. This is why the user does not need to write SPARQL queries by himself.

Author:

Andreas Eisenkolb (andreas.eisenkolb@gmail.com)

Constructor Summary

Constructors

Constructor and Description
QueryService(ObjectConnection connection, LDPathEvaluatorConfiguration evaluatorConfiguration)

Method Summary

Methods

Modifier and Type	Method and Description
QueryService	addCriteria(Criteria criteria) Adding a criteria object to the QueryService
QueryService	addCriteria(String ldpath) Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.
QueryService	addCriteria(String ldpath, Number value) Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.
QueryService	addCriteria(String ldpath, Number value, Comparison comparison) Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.
QueryService	addCriteria(String ldpath, String value) Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.
QueryService	addCriteria(String ldpath, String value, Comparison comparison) Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.
QueryService	addPrefix(String label, String url) Setting shortcut names for URI prefixes.
QueryService	addPrefixes(HashMap<String,String> prefixes) Setting multiple names for URI prefixes.
List<Annotation>	execute() Creates and executes the SPARQL query according to the criteria specified by the user.
<T extends ResourceObject> List<T>	execute(Class<T> type) Creates and executes the SPARQL query according to the criteria specified by the user.
org.apache.marmotta.ldpath.parser.Configuration	getConfiguration()
ArrayList<Criteria>	getCriteria()
LDPathEvaluatorConfiguration	getEvaluatorConfiguration()
Map<String,String>	getPrefixes()
QueryService	limit(Integer limit) Setting the limit value.
QueryService	offset(Integer offset) Setting the offset value.
<S extends QueryExtension> S	useExtension(Class<S> type) Creating and returning an instance of the passed type.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryService

public QueryService(ObjectConnection connection,
            LDPathEvaluatorConfiguration evaluatorConfiguration)

Method Detail

getPrefixes

public Map<String,String> getPrefixes()

getCriteria

public ArrayList<Criteria> getCriteria()

addCriteria

public QueryService addCriteria(String ldpath,
                       String value,
                       Comparison comparison)

Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.

Parameters:

ldpath - Syntax similar to XPath. Beginning from the Annotation object

comparison - The comparison mode, e.g. Comparison.EQ (=)

value - The constraint value

Returns:

itself to allow chaining.

addCriteria

public QueryService addCriteria(String ldpath,
                       Number value,
                       Comparison comparison)

Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.

Parameters:

ldpath - Syntax similar to XPath. Beginning from the Annotation object

comparison - The comparison mode, e.g. Comparison.EQ (=)

value - The constraint value

Returns:

itself to allow chaining.

addCriteria

public QueryService addCriteria(String ldpath,
                       String value)

Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects. Compared to the other addCriteria function, this function does not need a Comparison statement. Hence, the Comparison.EQ statement ("=") will be used automatically.

Parameters:

ldpath - Syntax similar to XPath. Beginning from the Annotation object

value - The constraint value

Returns:

itself to allow chaining.

addCriteria

public QueryService addCriteria(String ldpath,
                       Number value)

Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects. Compared to the other addCriteria function, this function does not need a Comparison statement. Hence, the Comparison.EQ statement ("=") will be used automatically.

Parameters:

ldpath - Syntax similar to XPath. Beginning from the Annotation object

value - The constraint value

Returns:

itself to allow chaining.

addCriteria

public QueryService addCriteria(String ldpath)

Setting a criteria for filtering eu.mico.platform.persistence.impl.AnnotationImpl objects.

Parameters:

ldpath - Syntax similar to XPath. Beginning from the Annotation object

Returns:

itself to allow chaining.

addCriteria

public QueryService addCriteria(Criteria criteria)

Adding a criteria object to the QueryService

Parameters:

criteria - The criteria object

Returns:

itself to allow chaining.

addPrefix

public QueryService addPrefix(String label,
                     String url)

Setting shortcut names for URI prefixes.

Parameters:

label - The label of the namespace, e.g. foaf

url - The URL

Returns:

itself to allow chaining.

addPrefixes

public QueryService addPrefixes(HashMap<String,String> prefixes)

Setting multiple names for URI prefixes.

Parameters:

prefixes - HashMap with multiple namespaces.

Returns:

itself to allow chaining.

limit

public QueryService limit(Integer limit)

Setting the limit value.

Parameters:

limit - The limit value.

Returns:

itself to allow chaining.

offset

public QueryService offset(Integer offset)

Setting the offset value.

Parameters:

offset - The offset value.

Returns:

itself to allow chaining.

execute

public List<Annotation> execute()
                         throws org.apache.marmotta.ldpath.parser.ParseException,
                                org.openrdf.repository.RepositoryException,
                                org.openrdf.query.MalformedQueryException,
                                org.openrdf.query.QueryEvaluationException

Creates and executes the SPARQL query according to the criteria specified by the user.

Returns:

the result set of annotations

Throws:

org.apache.marmotta.ldpath.parser.ParseException

org.openrdf.repository.RepositoryException

org.openrdf.query.MalformedQueryException

org.openrdf.query.QueryEvaluationException

execute

public <T extends ResourceObject> List<T> execute(Class<T> type)
                                       throws org.apache.marmotta.ldpath.parser.ParseException,
                                              org.openrdf.repository.RepositoryException,
                                              org.openrdf.query.MalformedQueryException,
                                              org.openrdf.query.QueryEvaluationException

Creates and executes the SPARQL query according to the criteria specified by the user.

Type Parameters:

T - type Type of the expected result.

Returns:

the result set

Throws:

org.apache.marmotta.ldpath.parser.ParseException

org.openrdf.repository.RepositoryException

org.openrdf.query.MalformedQueryException

org.openrdf.query.QueryEvaluationException

getConfiguration

public org.apache.marmotta.ldpath.parser.Configuration getConfiguration()

getEvaluatorConfiguration

public LDPathEvaluatorConfiguration getEvaluatorConfiguration()

useExtension

public <S extends QueryExtension> S useExtension(Class<S> type)
                                      throws IllegalAccessException,
                                             InstantiationException

Creating and returning an instance of the passed type. This allows the user to invoke specific methods of the extension class without loosing convenience of the fluid interface, Anno4j provides.

Type Parameters:

S - generic, because the type of the extension class can differ.

Parameters:

type - the type of the extension.

Returns:

an instance of the passed class

Throws:

IllegalAccessException

InstantiationException