Claude, I've now noticed you are actually the author of PA4RDF, and I'm wondering what your plans are for releasing a version of PA4RDF that uses Jena 3+. I would ask in a github issue, but I'm sure you've got one, as there are snapshots, and it seems better to keep the conversation all together.
On Mon, Apr 8, 2019 at 1:34 PM Dan Davis <[email protected]> wrote: > That is true - I was about to post that PA4RDF seems just what is needed. > > It is even possible that your RDF may have more properties than you expose > at the pojo layer. The examples deal mostly with Data Properties, and no > query language is mentioned. It is quite possible that this is not a > deficit of the package, but of the documentation. I also note that the > latest non-snapshot release is still on Jena 2, but that > > https://oss.sonatype.org/content/repositories/snapshots/org/xenei/PA4RDF/2.0-SNAPSHOT/ > is up to date enough. > > On Mon, Apr 8, 2019 at 8:51 AM Claude Warren <[email protected]> wrote: > >> PA4RDF is an OGM. It just views the subject of triples as an >> identifier for one or my POJOs. The properties are mapped to >> getter/setter methods and the objects are the values. The entity >> manager manages converting URL objects to POJOs. PA4RDF uses 2 >> annotations, one to map the POJO to the RDF subject and the other to >> identify the POJO properties that should be mapped to properties. >> >> Claude >> >> On Mon, Apr 8, 2019 at 7:00 AM Dan Davis <[email protected]> wrote: >> > >> > To me, it seems unfortunate to make the Resource do all the work, and >> make >> > it more than the subject of triples. Some labeled property graphs >> define >> > an OGM (Object/Graph Mapping). I wonder whether that concept has any >> > bearing here. >> > >> > Anyway, I've wished for an OGM sort of mapping to a POJO for awhile. >> One >> > annotation to say its a Jena resource. Another Annotation to say which >> > method returns its URI, and give an optional prefix. >> > >> > Additional annotations to label setters or properties by predicate - >> this >> > would not be too bad coupled with org.apache.jena.vocabulary. >> > >> > Might need different annotations for object properties and data >> properties. >> > >> > >> > On Sun, Apr 7, 2019 at 7:54 AM Claude Warren <[email protected]> wrote: >> > >> > > Thomas, >> > > >> > > I think that PA4RDF does/did what you want to do >> > > (https://github.com/Claudenw/PA4RDF) Basically, you define >> FoafPerson >> > > as an interface and annotate the getX methods to identify the >> > > properties that identify the value. Something like: >> > > >> > > {noformat} >> > > @Subject(namespace = "http://xmlns.com/foaf/0.1/";, >> > > class="http://xmlns.com/foaf/0.1/FoafPerson";) >> > > public interface FoafPerson { >> > > >> > > String getName(); >> > > @Predicate >> > > vod setName( String name ); >> > > boolean hasName(); >> > > } >> > > {noformat} >> > > >> > > Create an use an entity manager by requesting >> > > >> > > {noformat} >> > > FoafPerson fp = entityManager.read( resource, FoafPerson.class ); >> > > {noformat} >> > > >> > > Will create fp as an instance of FoafPerson backed by the specified >> > > resource. >> > > >> > > PA4RDF used dynamic proxies so it can create objects that are >> > > combinations of objects. All objects returned implement >> > > ResourceWrapper so you can allways call fp.getResource() to get the >> > > resource back from the object. >> > > >> > > Claude >> > > >> > > Note: If you decide to go this route use the 1.1 version as the >> > > current head branch is a different implementation and has some >> > > significant issues. >> > > >> > > >> > > >> > > On Wed, Apr 3, 2019 at 8:33 AM Thomas Francart >> > > <[email protected]> wrote: >> > > > >> > > > Hello >> > > > >> > > > Le mar. 2 avr. 2019 à 21:54, ajs6f <[email protected]> a écrit : >> > > > >> > > > > Personality and related types are described briefly here: >> > > > > >> > > > > >> > > > > >> > > >> https://jena.apache.org/documentation/notes/jena-internals.html#enhanced-nodes >> > > > >> > > > >> > > > Thanks, this describes what I would like to do : >> > > > >> > > > ``` >> > > > >> > > > 1. define an interface I for the new enhanced node. (You could >> use >> > > just >> > > > the implementation class, but we've stuck with the interface, >> because >> > > there >> > > > might be different implementations) >> > > > 2. define the implementation class C. This is just a front for >> the >> > > > enhanced node. All the state of C is reflected in the graph >> (except >> > > for >> > > > caching; but beware that the graph can change without notice). >> > > > 3. define an Implementation class for the factory. This class >> defines >> > > > methods canWrap and wrap, which test a node to see if it is >> allowed to >> > > > represent I and construct an implementation of Crespectively. >> > > > 4. Arrange that the personality of the graph maps the class of I >> to >> > > the >> > > > factory. At the moment we do this by using (a copy of) the >> built-in >> > > graph >> > > > personality as the personality for the enhanced graph. >> > > > >> > > > ``` >> > > > >> > > > > >> > > > > >> > > > > I know little about them, but to my understanding, that is not a >> > > > > well-developed part of Jena and the technical ideas there are not >> under >> > > > > active development. You are noticing that when you find the >> > > constructor odd >> > > > > and hard to fill; that's in part because it mixes Jena's API >> (Resource, >> > > > > Statement, Model, etc.) with its SPI (Node, Triple, Graph, etc.). >> > > > > >> > > > > Could you tell us a little more about what you are doing? Why do >> you >> > > want >> > > > > to extend Resource? >> > > > > >> > > > >> > > > I'd like to do : >> > > > >> > > > 1. Define an interface that extends Resource : >> > > > >> > > > ``` >> > > > public interface FoafPerson extends Resource { >> > > > public String getName(); >> > > > } >> > > > ``` >> > > > >> > > > 2. Define an implementation : >> > > > >> > > > ``` >> > > > public interface FoafPersonImpl implements FoafPerson extends >> > > ResourceImpl { >> > > > // constructor : how will this be called ??? >> > > > public FoafPersonImpl(Node node, EnhGraph graph) { >> > > > super(node, graph); >> > > > } >> > > > >> > > > @Override >> > > > public String getName() { >> > > > return this.getProperty(FOAF.name).getString(); >> > > > } >> > > > } >> > > > ``` >> > > > >> > > > 3. Define an Implementation class : >> > > > >> > > > ... here, I am lost >> > > > >> > > > 4. Maps the class I to the factory : >> > > > >> > > > ... here, I am lost >> > > > >> > > > 5. Use this; I'd like to be able to do : >> > > > >> > > > ``` >> > > > Model m = ...; >> > > > Resource r = ...; >> > > > // obtain a view on the Resource as a Foaf Person : >> > > > FoafPerson person = r.as(FoafPerson.class); >> > > > System.out.println(person.getName()); >> > > > ``` >> > > > >> > > > Any help in filling the blanks above would be appreciated ! >> > > > >> > > > Thanks >> > > > Thomas >> > > > >> > > > >> > > > > ajs6f >> > > > > >> > > > > > On Apr 2, 2019, at 3:48 PM, Thomas Francart < >> > > [email protected]> >> > > > > wrote: >> > > > > > >> > > > > > Hello >> > > > > > >> > > > > > I would like to declare data structure with an Interface that >> extends >> > > > > Jena >> > > > > > Resource and its implementation that extends Jena ResourceImpl >> in the >> > > > > same >> > > > > > way as >> > > > > > >> > > > > >> > > >> https://github.com/TopQuadrant/shacl/blob/a3f54abeffc691ff0b15bee7f049741eb6e00878/src/main/java/org/topbraid/shacl/model/SHShape.java >> > > > > > (interface) and >> > > > > > >> > > > > >> > > >> https://github.com/TopQuadrant/shacl/blob/a3f54abeffc691ff0b15bee7f049741eb6e00878/src/main/java/org/topbraid/shacl/model/impl/SHShapeImpl.java >> > > > > > (implementation, which indirectly extends ResourceImpl). >> > > > > > Is it a common and good practice ? >> > > > > > >> > > > > > The constructor of the implementation takes as an input (Node >> node, >> > > > > > EnhGraph graph). >> > > > > > I don't know how to obtain or build these Node and EnhGraph from >> > > plain >> > > > > > Resource / Model I am used to. I will be working with memory or >> > > > > TDB-backed >> > > > > > Models, if that matters. How can I obtain or build these so >> that I >> > > can >> > > > > call >> > > > > > the constructor of my data structure extending ResourceImpl, >> with a >> > > Node >> > > > > > and EnhGraph instance ? >> > > > > > >> > > > > > I feel this could be related to "Personality<RDFNode>", as can >> be >> > > seen at >> > > > > > >> > > > > >> > > >> https://github.com/TopQuadrant/shacl/blob/76257beb501381542361b52363329999363753ff/src/main/java/org/topbraid/shacl/model/SHFactory.java >> > > > > , >> > > > > > where RDF classes URI are associated to the corresponding Java >> > > classes. >> > > > > > >> > > > > > I am lost here, could someone shed some light on this design >> pattern >> > > ? >> > > > > > >> > > > > > Thanks >> > > > > > Thomas >> > > > > > >> > > > > > -- >> > > > > > >> > > > > > *Thomas Francart* -* SPARNA* >> > > > > > Web de *données* | Architecture de l'*information* | Accès aux >> > > > > > *connaissances* >> > > > > > blog : blog.sparna.fr, site : sparna.fr, linkedin : >> > > > > > fr.linkedin.com/in/thomasfrancart >> > > > > > tel : +33 (0)6.71.11.25.97, skype : francartthomas >> > > > > >> > > > > >> > > > >> > > > -- >> > > > >> > > > *Thomas Francart* -* SPARNA* >> > > > Web de *données* | Architecture de l'*information* | Accès aux >> > > > *connaissances* >> > > > blog : blog.sparna.fr, site : sparna.fr, linkedin : >> > > > fr.linkedin.com/in/thomasfrancart >> > > > tel : +33 (0)6.71.11.25.97, skype : francartthomas >> > > >> > > >> > > >> > > -- >> > > I like: Like Like - The likeliest place on the web >> > > LinkedIn: http://www.linkedin.com/in/claudewarren >> > > >> >> >> >> -- >> I like: Like Like - The likeliest place on the web >> LinkedIn: http://www.linkedin.com/in/claudewarren >> >
