Hi all,
At $-work, we are building an application on top of Apache Jena. After three
years, it slowly comes together, and the first role out will be soon. YAY, one
Apache Jena Business Application more! ;-)
Nevertheless, we still frequently stumble over the API. Here are two examples I
remember directly.
Graph defines contains(Triple) and contains(Node, Node, Node), same for find.
But only delete(Triple), add(Triple) and remove(Node,Node,Node). Why no comfort
variants for delete, add and remove?
Graph.contains work with matches because the same holds for Graph.find a
"contains exactly" question is not answerable. With exactly we mean
Graph.containsExactly(t1) is true iff the graph contains a triple t2 with
t1.equals(t2). Contains works differently compared to Set.contains, but why?
See snippet-1
To be honest, we can live with a "because nobody requested it this way" :D If
so, I would like to contribute our findings for version 4.0. I would like to
see Apache Jena profit from library user view or otherwise get enlightened.
Best Merlin
Code Snippet-1:
var o1 = NodeFactory.createLiteral("0", XSDDatatype.XSDdouble);
var o2 = NodeFactory.createLiteral("0.0", XSDDatatype.XSDdouble);
var t1 = Triple.create(s, p, o1);
var t2 = Triple.create(s, p, o2);
var graph = graph.add(t1); // GraphFactory.createDefaultGraph() omitted
t1.equals(t2); // false because o1 != o2
graph.contains(s, p, o2); // true because (s,p,o1) matches
graph.contains(t2); // true, even if t2 is not in the graph
