org.ontoware.rdf2go.util
Class RDFTool

java.lang.Object
  org.ontoware.rdf2go.util.RDFTool

public class RDFTool
extends java.lang.Object

RDFTool, a helper utility to cope with RDF in general. The accessor methods are also handled by the RDFReactor runtime.

This tool has been part of gnowsis.org.

Author:

Leo Sauermann (leo@gnowsis.com), 2003-2007, Max Völkel

Constructor Summary

RDFTool()

Method Summary

static Model	copyModel(Model m)
static java.lang.String	date2String(java.util.Date date) format the given date in a good date format: ISO 8601, using only the date and not the T seperator example: 2003-01-22 Timezone is ignored.
static java.lang.String	dateTime2DateString(java.util.Date date) Deprecated. use date2String(Date)
static java.lang.String	dateTime2String(java.util.Date date) format the given date in a good dateTime format: ISO 8601, using the T seperator and the - and : seperators accordingly. example: 2003-01-22T17:00:00
static Statement	findStatement(Model model, ResourceOrVariable subject, UriOrVariable predicate, NodeOrVariable object) find the first statement that fits the passed triple pattern and return it.
static java.text.DateFormat	getDateFormat() format to express dates in ISO 8601.
static java.text.DateFormat	getDateTimeFormat() get a DateFormat to format dates according to ISO 8601.
static java.lang.String	getGoodLabel(Node o, Model source) Get the Displaylabel of a Node.
static java.lang.String	getLabel(Node o) Get the label of a Node.
static java.lang.String	getShortName(java.lang.String uri) The passed uri identifies something on the web, probably a namespace.
static Node	getSingleValue(Model m, Resource res, URI pred) get the property pred of the resource res.
static Node	getSingleValue(ModelSet m, Resource res, URI pred)
static java.lang.String	getSingleValueString(Model m, Resource res, URI pred) read the values of a predicate of a resource.
static java.lang.String	getSingleValueString(ModelSet modelset, Resource res, URI pred) read the values of a predicate of a resource.
static Syntax	guessSyntax(java.lang.String filenname) guess the RDF syntax of a filename inspired by com.hp.hpl.jena.graph.impl.FileGraph#guessLang with the addition of toLowerCase
static java.lang.String	modelToString(Model model) convert a model to a string RDF/XML for serialization
static java.lang.String	modelToString(ModelSet modelset)
static java.lang.String	modelToString(ModelSet modelset, Syntax syntax) convert a modelset to a string for serialization
static java.lang.String	modelToString(Model model, Syntax syntax) convert a model to a string for serialization
static void	setSingleValue(Model m, Resource res, URI pred, Node value) set the property pred of the resource res.
static void	setSingleValue(Model m, Resource res, URI pred, java.lang.String value) set the property pred of the resource res.
static java.lang.String	sha1sum(java.lang.String data) compute the sha1sum of a string (useful for handling FOAF data).
static java.util.Date	string2Date(java.lang.String isodate) try to get a date out of a string.
static java.util.Date	string2DateTime(java.lang.String date) format the given date in a good date format: ISO 8601, using only the date and not the T seperator example: 2003-01-22 This ignores timezones.
static Model	stringToModel(java.lang.String rdfxml) convenience function to create a memModel from an RDF/XML-ABBREV stream
static Model	stringToModel(java.lang.String string, Syntax syntax) convenience function to create a memModel from a string

Methods inherited from class java.lang.Object

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

Constructor Detail

RDFTool

public RDFTool()

Method Detail

copyModel

public static Model copyModel(Model m)

Parameters:

m - the model to copy

Returns:

a copy of the model in a memory model

dateTime2DateString

public static java.lang.String dateTime2DateString(java.util.Date date)

Deprecated. use date2String(Date)

format the given date in a good date format: ISO 8601, using only the date and not the T seperator example: 2003-01-22 Timezone is ignored.

Parameters:

date -

Returns:

a formatted string.

dateTime2String

public static java.lang.String dateTime2String(java.util.Date date)

format the given date in a good dateTime format: ISO 8601, using the T seperator and the - and : seperators accordingly. example: 2003-01-22T17:00:00

Parameters:

date -

Returns:

a formatted string.

date2String

public static java.lang.String date2String(java.util.Date date)

format the given date in a good date format: ISO 8601, using only the date and not the T seperator example: 2003-01-22 Timezone is ignored.

Parameters:

date -

Returns:

a formatted string.

findStatement

public static Statement findStatement(Model model,
                                      ResourceOrVariable subject,
                                      UriOrVariable predicate,
                                      NodeOrVariable object)

find the first statement that fits the passed triple pattern and return it.

Parameters:

model - the model to search on

subject - subject

predicate - predicate

object - object

Returns:

a statement (the first found) or null, if nothing matched

Throws:

java.lang.RuntimeException - if the model throws an exception

getDateFormat

public static java.text.DateFormat getDateFormat()

format to express dates in ISO 8601. Timezone is ignored.

Returns:

the DateFormat to format dates (without time) according to ISO8601.

getDateTimeFormat

public static java.text.DateFormat getDateTimeFormat()

get a DateFormat to format dates according to ISO 8601. This ignored timezones.

Returns:

a dateformat.

getGoodLabel

public static java.lang.String getGoodLabel(Node o,
                                            Model source)

Get the Displaylabel of a Node. For resources, the "rdfs:label" property is returned, if there is none, the url is shortened to a localname. If it is a Literal, return the Lexical Form. If it is null, returns null Results may vary.

Parameters:

o - the node to check

source - the model to ask

Returns:

a string representation of the node or null.

getLabel

public static java.lang.String getLabel(Node o)

Get the label of a Node. If it is a resource, return the local name (the last part of the URI). If it is a Literal, return the Lexical Form (the value). If it is null, returns null.

Parameters:

o - the node to check

Returns:

a string representation of the node or null.

getShortName

public static java.lang.String getShortName(java.lang.String uri)

The passed uri identifies something on the web, probably a namespace. To shorten this, parse the url for something like a localname. Returns the last string after a '#' or a '/'.

Parameters:

uri - a URI

Returns:

a short name for it, for display.

getSingleValue

public static Node getSingleValue(Model m,
                                  Resource res,
                                  URI pred)

get the property pred of the resource res. If there is none, return null. If there are mutliple, return any.

Parameters:

m - the model to read from

res - the resource

pred - the predicate to read

Returns:

the value or null

getSingleValue

public static Node getSingleValue(ModelSet m,
                                  Resource res,
                                  URI pred)

getSingleValueString

public static java.lang.String getSingleValueString(Model m,
                                                    Resource res,
                                                    URI pred)

read the values of a predicate of a resource. If a value exists, return a string representation of it. When multiple triples with this subject/predicate exist, choose one at random.

Parameters:

m - the model to read from

res - the resource

pred - the predicate to read

Returns:

a string representation of the value, or null. Literals are returned using their Value (not toString()).

getSingleValueString

public static java.lang.String getSingleValueString(ModelSet modelset,
                                                    Resource res,
                                                    URI pred)

read the values of a predicate of a resource. If a value exists, return a string representation of it. When multiple triples with this subject/predicate exist, choose one at random.

Parameters:

modelset - the model to read from

res - the resource

pred - the predicate to read

Returns:

a string representation of the value, or null. Literals are returned using their Value (not toString()).

guessSyntax

public static Syntax guessSyntax(java.lang.String filenname)

guess the RDF syntax of a filename inspired by com.hp.hpl.jena.graph.impl.FileGraph#guessLang with the addition of toLowerCase

Parameters:

filenname - the filename, we will look at the suffix after "."

Returns:

the guessed RDF syntax, fallback is RDF/XML

modelToString

public static java.lang.String modelToString(Model model)

convert a model to a string RDF/XML for serialization

Parameters:

model - the model to convert

Returns:

modelToString

public static java.lang.String modelToString(ModelSet modelset)

modelToString

public static java.lang.String modelToString(Model model,
                                             Syntax syntax)

convert a model to a string for serialization

Parameters:

model - the model to convert

syntax - the syntax to use

Returns:

a string of this model, according to the passed syntax

modelToString

public static java.lang.String modelToString(ModelSet modelset,
                                             Syntax syntax)

convert a modelset to a string for serialization

Parameters:

modelset - the model to convert

syntax - the syntax to use

Returns:

a string of this model, according to the passed syntax

setSingleValue

public static void setSingleValue(Model m,
                                  Resource res,
                                  URI pred,
                                  Node value)

set the property pred of the resource res. If it exists, change it. If it not exists, create it. If the passed value is null, delete the statement

Parameters:

m - the model to manipulate

res - the rsource

pred - the predicate to set

value - a value or null

setSingleValue

public static void setSingleValue(Model m,
                                  Resource res,
                                  URI pred,
                                  java.lang.String value)

set the property pred of the resource res. If it exists, change it. If it not exists, create it. If value is null, delete the triple.

Parameters:

m - the model to manipulate

res - the rsource

pred - the predicate to set

value - a string or null

sha1sum

public static java.lang.String sha1sum(java.lang.String data)

compute the sha1sum of a string (useful for handling FOAF data).

Parameters:

data - the string to parse

Returns:

the sha1sum as string.

string2Date

public static java.util.Date string2Date(java.lang.String isodate)
                                  throws java.text.ParseException

try to get a date out of a string. If this works, return it, otherwise return null. Btw: the namespace of dateTime is http://www.w3.org/2001/XMLSchema#dateTime Timezone is ignored.

Parameters:

isodate - the XSD date as string.

Returns:

a parsed date or null, if this breaks

Throws:

java.text.ParseException

string2DateTime

public static java.util.Date string2DateTime(java.lang.String date)
                                      throws java.text.ParseException

format the given date in a good date format: ISO 8601, using only the date and not the T seperator example: 2003-01-22 This ignores timezones.

Parameters:

date - the date-string to parse

Returns:

a formatted string.

Throws:

java.text.ParseException

stringToModel

public static Model stringToModel(java.lang.String rdfxml)

convenience function to create a memModel from an RDF/XML-ABBREV stream

Parameters:

rdfxml - the serialized form of the model

Returns:

a Model

stringToModel

public static Model stringToModel(java.lang.String string,
                                  Syntax syntax)

convenience function to create a memModel from a string

Parameters:

string - the string with the serialized model

syntax - the syntax to use

Returns:

the model that was serialised.