| java.lang.Object
 com.hp.hpl.jena.ontology.OntTools
| OntTools | | public class OntTools (Code) | |
Some general utilities and algorithms to support developers working with the
general classes in the Jena ontology API. Warning these
utilities are experimental. Extensive testing has not yet
occurred (see
TestOntTools for basic unit tests), and in particular
performance testing has not been carried out yet. Users are advised to exercise
caution before relying on these utilities in production code. Please send
any comments or suggestions to the
Jena support email list.
author:
Ian Dickinson, HP Labs (email) |
| Inner Class :public static class DisjointSet | |
| Inner Class :public static class LCAIndex | |
| Inner Class :public static class Path extends ArrayList | |
| Inner Class :public static class PredicatesFilter extends Filter | |
| Method Summary | |
| protected static void | checkSolution(OntClass uCls, OntClass vCls, LCAIndex index)
Check to see if we have found a solution to the problem. | | public static Path | findShortestPath(Model m, Resource start, RDFNode end, Filter onPath)
Answer the shortest path from the start resource to the end RDF node,
such that every step on the path is accepted by the given filter. | | public static OntClass | getLCA(OntModel m, OntClass u, OntClass v)
Answer the lowest common ancestor of two classes in a given ontology. | | public static OntClass | getLCA(OntModel m, OntClass root, OntClass u, OntClass v)
Answer the lowest common ancestor of two classes, assuming that the given
class is the root concept to start searching from. | | protected static DisjointSet | lca(OntClass cls, OntClass uCls, OntClass vCls, LCAIndex index)
Compute the LCA disjoint set at cls, noting that we are
searching for the LCA of uCls and vCls.
Parameters:
cls - The class we are testing (this is 'u' in the Wiki article)
Parameters:
uCls - One of the two classes we are searching for the LCA of. | | public static List | namedHierarchyRoots(OntModel m)
Answer a list of the named hierarchy roots of a given
OntModel . | | protected static void | partitionByNamed(Iterator i, List named, List anon)
|
| checkSolution | | protected static void checkSolution(OntClass uCls, OntClass vCls, LCAIndex index)(Code) | | Check to see if we have found a solution to the problem.
TODO: we could throw an exception to simulate a non-local exit
here, since we've assumed that P is the unity set.
Parameters:
uCls -
Parameters:
vCls -
Parameters:
index - |
| findShortestPath | | public static Path findShortestPath(Model m, Resource start, RDFNode end, Filter onPath)(Code) | | Answer the shortest path from the start resource to the end RDF node,
such that every step on the path is accepted by the given filter. A path is a
List of RDF
Statement s. The subject of the first statement in the list is start,
and the object of the last statement in the list is end.
The onPath argument is a
Filter , which accepts a statement and returns
true if the statement should be considered to be on the path. To search for an unconstrained
path, pass
Filter.any as an argument. To search for a path whose predicates match a
fixed restricted set of property names, pass an instance of
PredicatesFilter .
If there is more than one path of minimal length from start to end,
this method returns an arbitrary one. The algorithm is blind breadth-first search,
with loop detection.
Parameters:
m - The model in which we are seeking a path
Parameters:
start - The starting resource
Parameters:
end - The end, or goal, node
Parameters:
onPath - A filter which determines whether a given statement can be considered partof the path A path, consisting of a list of statements whose first subject is start,and whose last object is end, or null if no such path exists. |
| getLCA | | public static OntClass getLCA(OntModel m, OntClass u, OntClass v)(Code) | | Answer the lowest common ancestor of two classes in a given ontology. This
is the class that is farthest from the root concept (defaulting to
owl:Thing which is a super-class of both u
and v. The algorithm is based on
Tarjan's
off-line LCA. The current implementation expects that the given model:
- is transitively closed over the
subClassOf relation
- can cheaply determine direct sub-class relations
Both of these conditions are true of the built-in Jena OWL reasoners,
such as
OntModelSpec.OWL_MEM_MICRO_RULE_INF , and external DL
reasoners such as Pellet.
Parameters:
m - The ontology model being queried to find the LCA, which should conformto the reasoner capabilities described above
Parameters:
u - An ontology class
Parameters:
v - An ontology class The LCA of u and v
exception:
JenaException - if the language profile of the given model does notdefine a top concept (e.g. owl:Thing) |
| getLCA | | public static OntClass getLCA(OntModel m, OntClass root, OntClass u, OntClass v)(Code) | | Answer the lowest common ancestor of two classes, assuming that the given
class is the root concept to start searching from. See
OntTools.getLCA(OntModel,OntClass,OntClass) for details.
Parameters:
m - The ontology model being queried to find the LCA, which should conformto the reasoner capabilities described above
Parameters:
root - The root concept, which will be the starting point for the algorithm
Parameters:
u - An ontology class
Parameters:
v - An ontology class The LCA of u and v
exception:
JenaException - if the language profile of the given model does notdefine a top concept (e.g. owl:Thing) |
| lca | | protected static DisjointSet lca(OntClass cls, OntClass uCls, OntClass vCls, LCAIndex index)(Code) | | Compute the LCA disjoint set at cls, noting that we are
searching for the LCA of uCls and vCls.
Parameters:
cls - The class we are testing (this is 'u' in the Wiki article)
Parameters:
uCls - One of the two classes we are searching for the LCA of. Wehave simplified the set P of pairs to the unity set {uCls,vCls}
Parameters:
vCls - One of the two classes we are searching for the LCA of. Wehave simplified the set P of pairs to the unity set {uCls,vCls}
Parameters:
index - A data structure mapping resources to disjoint sets (sincewe can't side-effect Jena resources), and which is used to record theLCA pairs |
| namedHierarchyRoots | | public static List namedHierarchyRoots(OntModel m)(Code) | | Answer a list of the named hierarchy roots of a given
OntModel . This
will be similar to the results of
OntModel.listHierarchyRootClasses ,
with the added constraint that every member of the returned iterator will be a
named class, not an anonymous class expression. The named root classes are
calculated from the root classes, by recursively replacing every anonymous class
with its direct sub-classes. Thus it can be seen that the values in the list
consists of the shallowest fringe of named classes in the hierarchy.
Parameters:
m - An ontology model A list of classes whose members are the named root classes of theclass hierarchy in m |
| partitionByNamed | | protected static void partitionByNamed(Iterator i, List named, List anon)(Code) | | Partition the members of an iterator into two lists, according to whether
they are named or anonymous classes
Parameters:
i - An iterator to partition
Parameters:
named - A list of named classes
Parameters:
anon - A list of anonymous classes |
|
|