eu.slipo.athenarc.triplegeo.utils

Class TripleGenerator

java.lang.Object

eu.slipo.athenarc.triplegeo.utils.TripleGenerator

public class TripleGenerator
extends java.lang.Object

Generates a collection of RDF triples from the (spatial & thematic) attributes of a given feature.

Version:

2.0

Author:

Kostas Patroumpas

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.lang.String	attrAssignedCategory
(package private) java.util.List<java.lang.String>	attrCategories
(package private) java.lang.String	attrCategoryURI
(package private) java.lang.String	attrDataSource
(package private) Mapping	attrMappings
(package private) java.util.Map<java.lang.String,java.lang.Integer>	attrStatistics
(package private) java.lang.String	attrURI
private static Configuration	currentConfig
com.vividsolutions.jts.geom.Envelope	mbr
Assistant	myAssistant
(package private) ValueChecker	myChecker
(package private) java.util.Map<java.lang.String,java.lang.String>	prefixes
private java.util.List<org.apache.jena.graph.Triple>	results

Constructor Summary

Constructors

Constructor and Description
TripleGenerator(Configuration config, Assistant assist) Constructs a TripleGenerator for transforming a feature (as a record of attributes) into RDF triples

Method Summary

Modifier and Type	Method and Description
private boolean	assignClassificationURI(java.util.Map<java.lang.String,java.lang.String> attrValues, Classification classific) Assigns a suitable URI for the category of this feature according to the classification scheme pertinent to the dataset
void	clearTriples() Cleans up all triples resulted from conversion so far
private void	createTriple4LanguageLiteral(java.lang.String s, java.lang.String p, java.lang.String o, java.lang.String lang) Creates an RDF triple with specific handling of literals having a language tag
private void	createTriple4PlainLiteral(java.lang.String s, java.lang.String p, java.lang.String o) Creates an RDF triple for a plain literal (without language tag or data type specification)
private void	createTriple4Resource(java.lang.String s, java.lang.String p, java.lang.String o) Creates an RDF triple with a resource as its object (i.e., non literal values)
private void	createTriple4TypedLiteral(java.lang.String s, java.lang.String p, java.lang.String o, org.apache.jena.datatypes.RDFDatatype d) Creates an RDF triple with specific handling of literals having a data type specification
private java.lang.String	expandNamespace(java.lang.String s) Expands the prefix into the full namespace of a given RDF node (usually, a predicate)
private java.util.List<java.lang.String>	getArgValues(java.util.List<java.lang.String> args, java.util.Map<java.lang.String,java.lang.String> attrValues) Provides a list of argument values to be used in calling a built-in function.
com.vividsolutions.jts.geom.Envelope	getMBR() Provides the MBR of the geographic dataset that has been transformed.
java.util.Map<java.lang.String,java.lang.Integer>	getStatistics() Provides the statistics collected during transformation (i.e., count of transformed values per attribute)
java.util.List<org.apache.jena.graph.Triple>	getTriples() Provides a collection of triples resulting from conversion (usually from a single input feature)
private void	insertVirtuosoPoint(java.lang.String uri, java.lang.String pointWKT) Insert a Point geometry of a spatial feature into the Jena model according to legacy Virtuoso RDF geometry specifications (concerning point geometries only)
private void	insertWGS84Point(java.lang.String uri, java.lang.String pointWKT) Insert a Point geometry of a spatial feature into the Jena model according to legacy WGS84 Geoposition RDF vocabulary
private void	insertWKTGeometry(java.lang.String uri, java.lang.String wkt, int srid, java.lang.String geomType) Inserts a typical WKT geometry of a spatial feature into the Jena model (suitable for GeoSPARQL compliant stores)
java.lang.String	transform(java.util.Map<java.lang.String,java.lang.String> row, java.lang.String wkt, int targetSRID, Classification classific) Converts the given feature (a tuple of thematic attributes and its geometry WKT) into RDF triples according to user-specified attribute mappings (in YML)
void	transformCategory2RDF(java.lang.String uuid, java.lang.String name, java.lang.String parent_uuid) Transforms a given category in a (possibly hierarchical) classification scheme into RDF triples IMPORTANT! Current handling fits the classification scheme suggested by the SLIPO ontology for Points of Interest (POI), but may be also applied against other classifications.
void	transformCustomThematic2RDF(java.lang.String uri, java.util.Map<java.lang.String,java.lang.String> attrValues, Classification classific) Transforms all thematic (i.e., non-spatial) attributes according to a custom ontology specified in a YML format
void	transformGeometry2RDF(java.lang.String uri, java.lang.String wkt, int srid, java.lang.String geomType) Converts representation of a geometry WKT into suitable RDF triple(s) depending on the specified spatial ontology
void	transformPlainThematic2RDF(java.lang.String uri, java.util.Map<java.lang.String,java.lang.String> attrValues) Handles all thematic (i.e., non-spatial) attributes of a feature, by simply issuing a triple with the original attribute name as property
void	updateMBR(com.vividsolutions.jts.geom.Geometry g) Updates the MBR of the geographic dataset as this is being transformed.
private void	updateStatistics(java.lang.String attrKey) Update statistics (currently only a counter) of values transformed for a particular attribute

Methods inherited from class java.lang.Object

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

Field Detail

myAssistant

public Assistant myAssistant

myChecker

ValueChecker myChecker

currentConfig

private static Configuration currentConfig

results

private java.util.List<org.apache.jena.graph.Triple> results

attrMappings

Mapping attrMappings

prefixes

java.util.Map<java.lang.String,java.lang.String> prefixes

attrURI

java.lang.String attrURI

attrCategoryURI

java.lang.String attrCategoryURI

attrDataSource

java.lang.String attrDataSource

attrAssignedCategory

java.lang.String attrAssignedCategory

attrStatistics

java.util.Map<java.lang.String,java.lang.Integer> attrStatistics

attrCategories

java.util.List<java.lang.String> attrCategories

mbr

public com.vividsolutions.jts.geom.Envelope mbr

Constructor Detail

TripleGenerator

public TripleGenerator(Configuration config,
                       Assistant assist)

Constructs a TripleGenerator for transforming a feature (as a record of attributes) into RDF triples

Parameters:

config - User-specified configuration for the transformation process.

Method Detail

updateMBR

public void updateMBR(com.vividsolutions.jts.geom.Geometry g)

Updates the MBR of the geographic dataset as this is being transformed.

Parameters:

g - Geometry that will be checked for possible expansion of the MBR of all features processed thus far

getMBR

public com.vividsolutions.jts.geom.Envelope getMBR()

Provides the MBR of the geographic dataset that has been transformed.

Returns:

The MBR of the transformed geometries.

getTriples

public java.util.List<org.apache.jena.graph.Triple> getTriples()

Provides a collection of triples resulting from conversion (usually from a single input feature)

Returns:

A list of RDF triples

clearTriples

public void clearTriples()

Cleans up all triples resulted from conversion so far

updateStatistics

private void updateStatistics(java.lang.String attrKey)

Update statistics (currently only a counter) of values transformed for a particular attribute

Parameters:

attrKey - The name of the attribute

getStatistics

public java.util.Map<java.lang.String,java.lang.Integer> getStatistics()

Provides the statistics collected during transformation (i.e., count of transformed values per attribute)

Returns:

A Map containing attribute names (keys) and their respective counts (values)

transform

public java.lang.String transform(java.util.Map<java.lang.String,java.lang.String> row,
                                  java.lang.String wkt,
                                  int targetSRID,
                                  Classification classific)

Converts the given feature (a tuple of thematic attributes and its geometry WKT) into RDF triples according to user-specified attribute mappings (in YML)

Parameters:

row - Attribute values for each thematic (non-spatial) attribute

wkt - Well-Known Text representation of the geometry

targetSRID - The EPSG identifier of the Coordinate Reference System of the geometry

classific - The classification scheme used in the category assigned to the feature

Returns:

The URI assigned to this feature and used in its resulting RDF triples

transformPlainThematic2RDF

public void transformPlainThematic2RDF(java.lang.String uri,
                                       java.util.Map<java.lang.String,java.lang.String> attrValues)
                                throws java.io.UnsupportedEncodingException

Handles all thematic (i.e., non-spatial) attributes of a feature, by simply issuing a triple with the original attribute name as property

Parameters:

uri - The URI assigned to this feature

attrValues - Attribute values for each thematic (non-spatial) attribute of the feature

Throws:

java.io.UnsupportedEncodingException

transformGeometry2RDF

public void transformGeometry2RDF(java.lang.String uri,
                                  java.lang.String wkt,
                                  int srid,
                                  java.lang.String geomType)

Converts representation of a geometry WKT into suitable RDF triple(s) depending on the specified spatial ontology

Parameters:

uri - The URI assigned to this feature

wkt - Well-Known Text representation of the geometry

srid - The EPSG identifier of the Coordinate Reference System of the geometry

geomType - The type of the geometry (e.g., POINT, POLYGON, etc.)

insertWKTGeometry

private void insertWKTGeometry(java.lang.String uri,
                               java.lang.String wkt,
                               int srid,
                               java.lang.String geomType)

Inserts a typical WKT geometry of a spatial feature into the Jena model (suitable for GeoSPARQL compliant stores)

Parameters:

uri - The URI assigned to this feature

wkt - Well-Known Text representation of the geometry

srid - The EPSG identifier of the Coordinate Reference System of the geometry

insertVirtuosoPoint

private void insertVirtuosoPoint(java.lang.String uri,
                                 java.lang.String pointWKT)

Insert a Point geometry of a spatial feature into the Jena model according to legacy Virtuoso RDF geometry specifications (concerning point geometries only)

Parameters:

uri - The URI assigned to this feature

pointWKT - Well-Known Text representation of the (point) geometry

insertWGS84Point

private void insertWGS84Point(java.lang.String uri,
                              java.lang.String pointWKT)

Insert a Point geometry of a spatial feature into the Jena model according to legacy WGS84 Geoposition RDF vocabulary

Parameters:

uri - The URI assigned to this feature

pointWKT - Well-Known Text representation of the (point) geometry

getArgValues

private java.util.List<java.lang.String> getArgValues(java.util.List<java.lang.String> args,
                                                      java.util.Map<java.lang.String,java.lang.String> attrValues)

Provides a list of argument values to be used in calling a built-in function.

Parameters:

args - List of arguments (parameters) of the built-in function.

attrValues - List of pairs of attributes and their respective values for a given feature

Returns:

Argument values to be used in the function call.

assignClassificationURI

private boolean assignClassificationURI(java.util.Map<java.lang.String,java.lang.String> attrValues,
                                        Classification classific)

Assigns a suitable URI for the category of this feature according to the classification scheme pertinent to the dataset

Parameters:

attrValues - Attribute values for each thematic (non-spatial) attribute of the feature

classific - The classification scheme used in the category assigned to the feature

Returns:

True if a URI has been assigned for the category; otherwise, False.

transformCustomThematic2RDF

public void transformCustomThematic2RDF(java.lang.String uri,
                                        java.util.Map<java.lang.String,java.lang.String> attrValues,
                                        Classification classific)
                                 throws java.io.UnsupportedEncodingException

Transforms all thematic (i.e., non-spatial) attributes according to a custom ontology specified in a YML format

Parameters:

uri - The URI assigned to this feature

attrValues - Attribute values for each thematic (non-spatial) attribute of the feature

classific - The classification scheme used in the category assigned to the feature

Throws:

java.io.UnsupportedEncodingException

transformCategory2RDF

public void transformCategory2RDF(java.lang.String uuid,
                                  java.lang.String name,
                                  java.lang.String parent_uuid)

Transforms a given category in a (possibly hierarchical) classification scheme into RDF triples IMPORTANT! Current handling fits the classification scheme suggested by the SLIPO ontology for Points of Interest (POI), but may be also applied against other classifications.

Parameters:

uuid - A universally unique identifier (UUID) assigned to the category

name - The name of this category according to the classification

parent_uuid - The universally unique identifier (UUID) assigned to the parent of this category in the classification scheme

expandNamespace

private java.lang.String expandNamespace(java.lang.String s)

Expands the prefix into the full namespace of a given RDF node (usually, a predicate)

Parameters:

s - A prefixed name with a prefix label and a local part, separated by a colon ":"

Returns:

A URI by concatenating the expanded namespace associated with the prefix and the local part

createTriple4LanguageLiteral

private void createTriple4LanguageLiteral(java.lang.String s,
                                          java.lang.String p,
                                          java.lang.String o,
                                          java.lang.String lang)

Creates an RDF triple with specific handling of literals having a language tag

Parameters:

s - Triple subject

p - Triple predicate

o - Triple object literal

lang - -- Language specification of the literal value

createTriple4PlainLiteral

private void createTriple4PlainLiteral(java.lang.String s,
                                       java.lang.String p,
                                       java.lang.String o)

Creates an RDF triple for a plain literal (without language tag or data type specification)

Parameters:

s - -- Triple subject

p - -- Triple predicate

o - -- Triple object literal

createTriple4Resource

private void createTriple4Resource(java.lang.String s,
                                   java.lang.String p,
                                   java.lang.String o)

Creates an RDF triple with a resource as its object (i.e., non literal values)

Parameters:

s - -- Triple subject

p - -- Triple predicate

o - -- Triple object resource

createTriple4TypedLiteral

private void createTriple4TypedLiteral(java.lang.String s,
                                       java.lang.String p,
                                       java.lang.String o,
                                       org.apache.jena.datatypes.RDFDatatype d)

Creates an RDF triple with specific handling of literals having a data type specification

Parameters:

s - -- Triple subject

p - -- Triple predicate

o - -- Triple object literal

d - -- Data type specification of the literal value