Comments on OWL-API

Note: these notes are based on the version 1.0 (15/10/2003) of the OWL API. Some things have changed since then and these notes have not have been updated.

There is now a better and up to date introduction on the OWL API web site.

The current 1.2 alignement API works correctly with the version 1.2 (09/03/2004) of the OWL API. The version available under anonymous CVS works with version (21/03/2005) of the OWL API.

Where to get it?

https://sourceforge.net/projects/owlapi

The code is partly documented and this can be read in the javadoc directory. This paper is a must have read to understand the philosophy behind this API.

What is in the package

There are two packages: owlbin and owlsrc. They are complementary, as can be noted when looking at their directories:

owl-bin:
drwxrwxr-x  18 euzenat  unknown   612 Dec  2 14:23 javadoc
   => documentation for API and all the code.
drwxrwxr-x  14 euzenat  unknown   476 Dec  2 14:24 lib
   => set of Jar files to be used for running applications
-rwxrwxr-x   1 euzenat  unknown   594 Dec  2 14:47 processor
   => a shell script for running the processor example
-rw-rw-r--   1 euzenat  unknown  1312 Oct 15 10:24 readme-bin.html
   => instructions for running it (see next item).

owl-src:
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 api (*)
    => API source and tests
drwxrwxr-x    7 euzenat  unknown   238 Dec  6 13:52 build
    => build results (see below for its architecture)
-rw-rw-r--    1 euzenat  unknown  9827 Oct 14 18:10 common.xml
-rw-rw-r--    1 euzenat  unknown  4702 Oct 14 18:10 dependencies.png
    => picture for the readme.html
-rw-rw-r--    1 euzenat  unknown  2305 Oct 14 18:10 example-build.xml
    => seems to be just a build file pattern.
drwxrwxr-x    4 euzenat  unknown   136 Dec  6 13:30 examples (*)
    => example uses (this is only the Processor.java class)
drwxrwxr-x    8 euzenat  unknown   272 Dec  6 13:30 ext
    => contains libraries required for building and using owlapi
       (dig, getopt, junit, log4j, rdfapi, servlet).
-rw-rw-r--    1 euzenat  unknown  1333 Oct 14 18:10 ext.xml
    => ant build file include.
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 impl (*)
    => One implementation of the API.
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 inference (*)
    => Inferencing addition to the API.
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 io (*)
    => Rendering methods from the API.
-rw-rw-r--    1 euzenat  unknown   157 Oct 14 18:10 license.txt
    => LGPL.
-rw-rw-r--    1 euzenat  unknown  3554 Oct 14 18:10 modules.xml
-rw-rw-r--    1 euzenat  unknown  1066 Oct 14 18:10 names.xml
    => These are ant build include files.
drwxrwxr-x    3 euzenat  unknown   102 Dec  6 13:30 owlapi
    => Contains the and master build file build.xml
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 owltest
    => Junit tests?
drwxrwxr-x    4 euzenat  unknown   136 Dec  6 13:30 rdfparser (*)
    => OWL/RDF parser and renderer.
-rw-rw-r--    1 euzenat  unknown  1312 Oct 15 10:14 readme-bin.html
    => Readme file on how to use the binary package.
-rw-rw-r--    1 euzenat  unknown  3605 Oct 14 18:10 readme.html
    => Readme file on how to use the sources.
drwxrwxr-x  106 euzenat  unknown  3604 Dec  6 13:30 resources
    => Contains the complete W3C OWL test set.
drwxrwxr-x    4 euzenat  unknown   136 Dec  6 13:30 servlet (*)
    => An example of a servlet loading an OWL/RDF ontology and
      diagnosing the OWL sub language it uses.
drwxrwxr-x    5 euzenat  unknown   170 Dec  6 13:30 validation (*)
    => A tool diagnosing the the OWL sub language used by an ontology.

The directories marked with a (*) corresponds to the sections of the package containing real code. They usually contain a src directory. These directories will generate a corresponding directory in the build process (see below).

The missing files in src can be generated by rebuilding owl-api! (see below).

Running examples

The processor example parses a OWL/RDF file whose URI is given as argument and generates an output which can be:

--abstract -a

Produce OWL Abstract Syntax

--tptp -t

Produce TPTP

--warn -w

Report warnings & errors

--renderer=className -r

Use the given class for output.

--impl=className -i

Use the given class as the default implementation of OWLConnection.

--validate[=lite|dl] -v

Validate. If no level is given, validates as DL.

--help -?

Print this message

For instance:

$ ./processor -a file://<yourpath>/owl/resources/transitive2.owl
[Namespaces: 
  rdf   = http://www.w3.org/1999/02/22-rdf-syntax-ns#
  xsd   = http://www.w3.org/2001/XMLSchema#
  rdfs  = http://www.w3.org/2000/01/rdf-schema#
  owl   = http://www.w3.org/2002/07/owl#
  a     = http://www.example.org/ontology#
]

Ontology(

 annotation(rdfs:comment [An example OWL ontology^^http://www.w3.org/2001/XMLSchema#string])

 ObjectProperty(a:p Transitive Functional)

)

$ ./processor --renderer=org.semanticweb.owl.io.owl_rdf.Renderer file://<yourpath>/owl/resources/transitive2.owl
<?Xml version="1.0"?>
<!DOCTYPE owl [
<!ENTITY owl  "http://www.w3.org/2002/07/owl#" >
<!ENTITY xsd  "http://www.w3.org/2000/10/XMLSchema#" >
<!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
<!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#" >
]>
<rdf:RDF
 xmlns:rdf      ="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
 xmlns:rdfs     ="http://www.w3.org/2000/01/rdf-schema#"
 xmlns:owl      ="http://www.w3.org/2002/07/owl#"
 xmlns:a        ="http://www.example.org/ontology#"
>
<!-- Need to support further ontology metadata, import still missing -->
        <owl:Ontology rdf:about="file:///Volumes/Skratsh/JAVA/owlapi/owl/resources/transitive2.owl" />
        <owl:ObjectProperty rdf:about="http://www.example.org/ontology#p">
                <rdf:type rdf:resource="&owl;TransitiveProperty" />
                <rdf:type rdf:resource="&owl;FunctionalProperty" />
        </owl:ObjectProperty>



</rdf:RDF>

Beware: the interface requires an URL (not a filename) and is very sensitive to any potential problem with them.

Rebuilding OWLAPI

Can be build by:

$ cd owlapi
$ ant 
    => compiles everything
$ ant run.test
    => runs unit tests (requires ant junit extension)
$ ant javadoc
    => generates documentation (done with compile?).

drwxrwxr-x   3 euzenat  unknown       102 Dec  6 13:55 class
    => Java .class files
drwxrwxr-x  14 euzenat  unknown       476 Dec  6 13:55 javadoc
    => The documentation
drwxrwxr-x   3 euzenat  unknown       102 Dec  6 13:55 lib
    => one Jar archive bearing the name of the section.

The binary distribution itself can be regenerated by using the "distribution.bin" ant switch.

$ ant distribution.bin