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?

http://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).
and
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 only intersection is the readme-bin.html file.

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)

)
or
$ ./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?).
The results are generated within the build directory. It contains a number of directories corresponding the the various sections of the package. Each of them contains the following structure:
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 javadoc and lib directories of the binary package contains the "union" of the files found in theses.

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

$ ant distribution.bin


http://alignapi.gforge.inria.fr/owlapi.html

$Id: owlapi.html 467 2007-04-21 06:06:36Z euzenat $