org.apache.stanbol.entityhub.servicesapi.util

Class ModelUtils

java.lang.Object

org.apache.stanbol.entityhub.servicesapi.util.ModelUtils

public final class ModelUtils
extends Object

Utilities useful for implementations of the Entityhub Model

Author:

Rupert Westenthaler

Field Summary

Fields

Modifier and Type	Field and Description
static Comparator<Representation>	RESULT_SCORE_COMPARATOR Comparator based on the RdfResourceEnum.resultScore property that assumes that values of this property implement Comparable.

Method Summary

Methods

Modifier and Type	Method and Description
static <T> Collection<T>	addToCollection(Iterator<? extends T> it, Collection<T> c) Adds the elements of the Iterator to the parsed Collection
static <T> Set<T>	addToSet(Iterator<? extends T> it, Set<T> set) Adds the elements of the Iterator to the parsed Set
static <T> Collection<T>	asCollection(Iterator<? extends T> it) Copies all elements of the parsed Iterator to a ArrayList.
static <T> Set<T>	asSet(Iterator<? extends T> it) Copies all elements of the parsed Iterator to a HashSet.
static void	checkValues(ValueFactory valueFactory, Object value, Collection<Object> results) Processes a value parsed as object to the representation.
static String	getAboutRepresentation(Representation metadata) Getter for the id of the Entity the parsed metadata are about.
static String[]	getNamespaceLocalName(String uri) Splits up a URI in local name and namespace based on the following rules If URI starts with "urn:" and last index of ':' == 3 than the there is no namespace and the whole URI is a local name if the uri starts with "urn:" and the last index of ':' ia > 3, than the last index ':' is used.
static QName	getQName(String uri) This Method uses getNamespaceLocalName(String) to split up namespace and local name.
static String	getRepresentationInfo(Representation rep) String representation of the parsed Representation inteded for DEBUG level loggings.
static UUID	randomUUID() TODO: Maybe we need a better way to generate unique IDs
static void	setSeed(long seed)

Methods inherited from class java.lang.Object

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

Field Detail

RESULT_SCORE_COMPARATOR

public static final Comparator<Representation> RESULT_SCORE_COMPARATOR

Comparator based on the RdfResourceEnum.resultScore property that assumes that values of this property implement Comparable. The Representation with the highest score will be first

Method Detail

randomUUID

public static UUID randomUUID()

TODO: Maybe we need a better way to generate unique IDs

Returns:

setSeed

public static void setSeed(long seed)

checkValues

public static void checkValues(ValueFactory valueFactory,
               Object value,
               Collection<Object> results)

Processes a value parsed as object to the representation. This processing includes:

• Removal of null values
• Converting URIs and URLs to Reference
• Converting String[] with at least a single entry where the first entry is not null to Text (the second entry is used as language. Further entries are ignored.
• Recursive calling of this Method if a Iterable (any Array or Collection), Iterator or Enumeration is parsed.
• All other Objects are added to the result list

TODO: Maybe we need to enable an option to throw IllegalArgumentException in case any of the parsed values is invalid. Currently invalid values are just ignored.

Parameters:

value - the value to parse

results - the collections the results of the parsing are added to.

getRepresentationInfo

public static String getRepresentationInfo(Representation rep)

String representation of the parsed Representation inteded for DEBUG level loggings.

Parameters:

rep - the representation

Returns:

the string

asCollection

public static <T> Collection<T> asCollection(Iterator<? extends T> it)

Copies all elements of the parsed Iterator to a ArrayList. To use other Set implementations that ArrayList you can use {@link #addToCollection(Iterator, Collection)

Type Parameters:

T - the generic type of the returned Collection

Parameters:

it - the Iterator with elements compatible to T

Returns:

the collection containing all elements of the iterator

Throws:

IllegalArgumentException - if the parsed Iterator is null

addToCollection

public static <T> Collection<T> addToCollection(Iterator<? extends T> it,
                                Collection<T> c)

Adds the elements of the Iterator to the parsed Collection

Type Parameters:

T - the type of the collection

Parameters:

it - the iterator over elements that are compatible to T

c - the collection to add the elements

Returns:

the parsed Collections with the added Elements

Throws:

IllegalArgumentException - if the parsed Collection is null.

asSet

public static <T> Set<T> asSet(Iterator<? extends T> it)

Copies all elements of the parsed Iterator to a HashSet. To use other Set implementations that HashSet you can use addToSet(Iterator, Set)

Type Parameters:

T - the generic type of the returned set

Parameters:

it - the Iterator with elements compatible to T

Returns:

the set containing all elements of the iterator

Throws:

IllegalArgumentException - if the parsed Iterator is null

addToSet

public static <T> Set<T> addToSet(Iterator<? extends T> it,
                  Set<T> set)

Adds the elements of the Iterator to the parsed Set

Type Parameters:

T - the type of the set

Parameters:

it - the iterator over elements that are compatible to T

set - the set to add the elements

Returns:

the parsed Set with the added Elements

Throws:

IllegalArgumentException - if the parsed Set is null.

getNamespaceLocalName

public static String[] getNamespaceLocalName(String uri)

Splits up a URI in local name and namespace based on the following rules

• If URI starts with "urn:" and last index of ':' == 3 than the there is no namespace and the whole URI is a local name
• if the uri starts with "urn:" and the last index of ':' ia > 3, than the last index ':' is used.
• split by the last index of '#' if index >= 0
• split by the last index of '/' if index >= 0
• return after the first split
• return the whole URI as local name if no split was performed.

Parameters:

uri - The uri

Returns:

A array with two fields. In the first the namespace is stored ( might be null. In the second the local name is stored.

getQName

public static QName getQName(String uri)

This Method uses getNamespaceLocalName(String) to split up namespace and local name. It uses also the Data in the NamespaceEnum to retrieve prefixes for Namespaces.

Parameters:

uri - the URI

Returns:

the QName

getAboutRepresentation

public static String getAboutRepresentation(Representation metadata)
                                     throws IllegalStateException

Getter for the id of the Entity the parsed metadata are about.

Parameters:

metadata - the metadata

Returns:

the id of the entity or null if the parsed Representation is null or does not define a value for RdfResourceEnum.aboutRepresentation

Throws:

IllegalStateException