se.kth.cid.metadata.rdf
Class RDFLangStringHandler

java.lang.Object
  |
  +--se.kth.cid.metadata.rdf.RDFLangStringHandler

public class RDFLangStringHandler

extends Object

LOM-LangString extraction utilities (from a RDF-Model).

A LangString contains an oroginal string in a specified language and a set of translations.

This class allows you to

1. Extract a single single string in one language with the function @link #extractLangStringTranslation
2. Extract a LangString with the function @link #extractPossibleLangString or @link #extractKnownLangString
3. Extract a set of LangStrings with the function @link #extractLangStrings

Version:

$Revision: $

Author:

Matthias Palmer

Method Summary

static String	excavateValue(org.w3c.rdf.model.RDFNode node, org.w3c.rdf.model.Model model, int counter) This function excavates the value of a resource via a traversion of possible several resources linked together via the rdf:value property until a literal is found. It can be thought of as a part of the dumbdown algorithm as defined by Dublin Core.
static MetaData.LangStringType	extractKnownLangString(org.w3c.rdf.model.Resource langstring, org.w3c.rdf.model.Model model) Extracs original string with possibly one or several translations.
static MetaData.LangStringType[]	extractLangStrings(org.w3c.rdf.model.Model langstrings, org.w3c.rdf.model.Model model)
static MetaData.LangString	extractLangStringTranslation(org.w3c.rdf.model.Model translationModel, org.w3c.rdf.model.Model model)
static MetaData.LangStringType	extractPossibleLangString(org.w3c.rdf.model.RDFNode node, org.w3c.rdf.model.Model model) Extracts a LangString if there is any.

Methods inherited from class java.lang.Object

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

Method Detail

extractLangStrings

public static MetaData.LangStringType[] extractLangStrings(org.w3c.rdf.model.Model langstrings,
                                                           org.w3c.rdf.model.Model model)
                                                    throws org.w3c.rdf.model.ModelException

extractPossibleLangString

public static MetaData.LangStringType extractPossibleLangString(org.w3c.rdf.model.RDFNode node,
                                                                org.w3c.rdf.model.Model model)
                                                         throws org.w3c.rdf.model.ModelException

Extracts a LangString if there is any. The alternatives are:

1. It's a LangString resource, extract via @link #extractKnownLangString.
2. It's another resource, a value is excavated via the @link #dumbDownTranslation algorithm.
3. It's a literal, A LangString is constructed with only one translation with language set to null.

See Also:

#dumbDownTranslation, extractKnownLangString(org.w3c.rdf.model.Resource, org.w3c.rdf.model.Model)

extractKnownLangString

public static MetaData.LangStringType extractKnownLangString(org.w3c.rdf.model.Resource langstring,
                                                             org.w3c.rdf.model.Model model)
                                                      throws org.w3c.rdf.model.ModelException

Extracs original string with possibly one or several translations. A LangString consists of an array of translations where each translation is a string and a language.
The original String appears first in the array of translations.

Returns:

MetaData.LangStringType i.e just an class wrapped around an array of translations what LOM defines as a langstring or null if no string where found.

See Also:

extractLangStringTranslation(org.w3c.rdf.model.Model, org.w3c.rdf.model.Model)

extractLangStringTranslation

public static MetaData.LangString extractLangStringTranslation(org.w3c.rdf.model.Model translationModel,
                                                               org.w3c.rdf.model.Model model)
                                                        throws org.w3c.rdf.model.ModelException

excavateValue

public static String excavateValue(org.w3c.rdf.model.RDFNode node,
                                   org.w3c.rdf.model.Model model,
                                   int counter)
                            throws org.w3c.rdf.model.ModelException

This function excavates the value of a resource via a traversion of possible several resources linked together via the rdf:value property until a literal is found.
It can be thought of as a part of the dumbdown algorithm as defined by Dublin Core.

Parameters:

node - the starting point, can be a literal (done) or a resource search value for.

model - the model to search statements in.

count - the maximum number of traversions to be done before the algorithm aborts (avoids loops)

Returns:

String null if no value was found.