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 >
