org.hobbit.utils.rdf

Class RdfHelper

java.lang.Object

org.hobbit.utils.rdf.RdfHelper

public class RdfHelper
extends Object

Implements simple methods to get data from a given RDF Model.

Author:

Michael Röder (roeder@informatik.uni-leipzig.de)

Field Summary

Fields

Modifier and Type	Field and Description
static String	HASH_SELF_URI Replacement URI for the resource.
private static org.slf4j.Logger	LOGGER

Constructor Summary

Constructors

Constructor and Description
RdfHelper()

Method Summary

Modifier and Type	Method and Description
protected static Calendar	getCalendarValue(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate, org.apache.jena.datatypes.xsd.XSDDatatype dateType)
static Calendar	getDateTimeValue(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the object as Calendar of the first triple that has the given subject and predicate and that can be found in the given model.
static Calendar	getDateValue(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the object as Calendar of the first triple that has the given subject and predicate and that can be found in the given model.
static String	getDescription(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource resource) Returns the description, i.e., the value of rdfs:comment, of the given Resource if it is present in the given Model.
static Duration	getDurationValue(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the object as Duration of the first triple that has the given subject and predicate and that can be found in the given model.
static String	getLabel(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource resource) Returns the label of the given Resource if it is present in the given Model.
static org.apache.jena.rdf.model.Literal	getLiteral(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the first triple literal that has the given subject and predicate and that can be found in the given model.
static org.apache.jena.rdf.model.Resource	getObjectResource(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the object as Resource of the first triple that has the given subject and predicate and that can be found in the given model.
static List<org.apache.jena.rdf.model.Resource>	getObjectResources(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the objects as Resources of all triples that have the given subject and predicate and that can be found in the given model.
static String	getStringValue(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the object as String of the first triple that has the given subject and predicate and that can be found in the given model.
static List<String>	getStringValues(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Resource subject, org.apache.jena.rdf.model.Property predicate) Returns the objects as Strings of all triples that have the given subject and predicate and that can be found in the given model.
static List<org.apache.jena.rdf.model.Resource>	getSubjectResources(org.apache.jena.rdf.model.Model model, org.apache.jena.rdf.model.Property predicate, org.apache.jena.rdf.model.Resource object) Returns a list of subjects of triples that have the given object and predicate and that can be found in the given model.
static String	hashProperties(org.apache.jena.rdf.model.StmtIterator statements) Computes a SHA1 hash of sorted and serialized resource properties.
private static String	serializeStatement(org.apache.jena.rdf.model.Statement stmt)

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

private static final org.slf4j.Logger LOGGER

HASH_SELF_URI

public static String HASH_SELF_URI

Replacement URI for the resource. Currently has no effect on actual hash computation.

Constructor Detail

RdfHelper

public RdfHelper()

Method Detail

getLabel

public static String getLabel(org.apache.jena.rdf.model.Model model,
                              org.apache.jena.rdf.model.Resource resource)

Returns the label of the given Resource if it is present in the given Model.

Parameters:

model - the model that should contain the label

resource - the resource for which the label is requested

Returns:

the label of the resource or null if such a label does not exist

getDescription

public static String getDescription(org.apache.jena.rdf.model.Model model,
                                    org.apache.jena.rdf.model.Resource resource)

Returns the description, i.e., the value of rdfs:comment, of the given Resource if it is present in the given Model.

Parameters:

model - the model that should contain the label

resource - the resource for which the label is requested

Returns:

the description of the resource or null if such a label does not exist

getStringValue

public static String getStringValue(org.apache.jena.rdf.model.Model model,
                                    org.apache.jena.rdf.model.Resource subject,
                                    org.apache.jena.rdf.model.Property predicate)

Returns the object as String of the first triple that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple null works like a wildcard.

predicate - the predicate of the triple null works like a wildcard.

Returns:

object of the triple as String or null if such a triple couldn't be found

getStringValues

public static List<String> getStringValues(org.apache.jena.rdf.model.Model model,
                                           org.apache.jena.rdf.model.Resource subject,
                                           org.apache.jena.rdf.model.Property predicate)

Returns the objects as Strings of all triples that have the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triples

subject - the subject of the triples. null works like a wildcard.

predicate - the predicate of the triples. null works like a wildcard.

Returns:

objects of the triples as Strings

getDateValue

public static Calendar getDateValue(org.apache.jena.rdf.model.Model model,
                                    org.apache.jena.rdf.model.Resource subject,
                                    org.apache.jena.rdf.model.Property predicate)

Returns the object as Calendar of the first triple that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple. null works like a wildcard.

predicate - the predicate of the triple. null works like a wildcard.

Returns:

object of the triple as Calendar or null if such a triple couldn't be found or the value can not be read as XSDDate

getDateTimeValue

public static Calendar getDateTimeValue(org.apache.jena.rdf.model.Model model,
                                        org.apache.jena.rdf.model.Resource subject,
                                        org.apache.jena.rdf.model.Property predicate)

Returns the object as Calendar of the first triple that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple. null works like a wildcard.

predicate - the predicate of the triple. null works like a wildcard.

Returns:

object of the triple as Calendar or null if such a triple couldn't be found or the value can not be read as XSDDateTime

getCalendarValue

protected static Calendar getCalendarValue(org.apache.jena.rdf.model.Model model,
                                           org.apache.jena.rdf.model.Resource subject,
                                           org.apache.jena.rdf.model.Property predicate,
                                           org.apache.jena.datatypes.xsd.XSDDatatype dateType)

getDurationValue

public static Duration getDurationValue(org.apache.jena.rdf.model.Model model,
                                        org.apache.jena.rdf.model.Resource subject,
                                        org.apache.jena.rdf.model.Property predicate)

Returns the object as Duration of the first triple that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple. null works like a wildcard.

predicate - the predicate of the triple. null works like a wildcard.

Returns:

object of the triple as Duration or null if such a triple couldn't be found or the value can not be read as XSDDuration

getLiteral

public static org.apache.jena.rdf.model.Literal getLiteral(org.apache.jena.rdf.model.Model model,
                                                           org.apache.jena.rdf.model.Resource subject,
                                                           org.apache.jena.rdf.model.Property predicate)

Returns the first triple literal that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple. null works like a wildcard.

predicate - the predicate of the triple. null works like a wildcard.

Returns:

literal of the triple or null if such a literal couldn't be found

getObjectResource

public static org.apache.jena.rdf.model.Resource getObjectResource(org.apache.jena.rdf.model.Model model,
                                                                   org.apache.jena.rdf.model.Resource subject,
                                                                   org.apache.jena.rdf.model.Property predicate)

Returns the object as Resource of the first triple that has the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple

predicate - the predicate of the triple

Returns:

object of the triple as Resource or null if such a triple couldn't be found

getObjectResources

public static List<org.apache.jena.rdf.model.Resource> getObjectResources(org.apache.jena.rdf.model.Model model,
                                                                          org.apache.jena.rdf.model.Resource subject,
                                                                          org.apache.jena.rdf.model.Property predicate)

Returns the objects as Resources of all triples that have the given subject and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

subject - the subject of the triple

predicate - the predicate of the triple

Returns:

List of object of the triples as Resource

getSubjectResources

public static List<org.apache.jena.rdf.model.Resource> getSubjectResources(org.apache.jena.rdf.model.Model model,
                                                                           org.apache.jena.rdf.model.Property predicate,
                                                                           org.apache.jena.rdf.model.Resource object)

Returns a list of subjects of triples that have the given object and predicate and that can be found in the given model.

Parameters:

model - the model that should contain the triple

predicate - the predicate of the triple

object - the object of the triple

Returns:

List of subject of the triples as Resource

hashProperties

public static String hashProperties(org.apache.jena.rdf.model.StmtIterator statements)

Computes a SHA1 hash of sorted and serialized resource properties.

Parameters:

resource - the resource object for which this method computes the hash.

Returns:

the computed hash.

serializeStatement

private static String serializeStatement(org.apache.jena.rdf.model.Statement stmt)