[protege-discussion] nullpointer exception in the loadKnowledgeBase method

[Olivier Mocquais RD-BIZZ]

Hi,

I want to save a jdbc knowledge base into a pprj file.

I use the Protégé API and this java code, but it doesn't work, I have a 
NullPointerException when the loadKnowledgeBase method is called. The 
database and the table exists with many information.

WARNING: Unable to load knowledgebase jdbc:mysql://localhost/protege -- 
java.lang.NullPointerException
    at 
edu.stanford.smi.protege.storage.database.DatabaseKnowledgeBaseFactory.initializeKB(Unknown 
Source)
    at 
edu.stanford.smi.protege.storage.database.DatabaseKnowledgeBaseFactory.loadKnowledgeBase(Unknown 
Source)

String username = "root";
String password = "system";
String driver = "com.mysql.jdbc.Driver";
String tablename = "protegekb";
Collection errors = new ArrayList();
DatabaseKnowledgeBaseFactory myFactory = new DatabaseKnowledgeBaseFactory();
Project prj = Project.createNewProject(myFactory, errors);
prj.setProjectFilePath("myproject.pprj");
prj.setKnowledgeBaseFactory(myFactory);
KnowledgeBase kb = prj.getKnowledgeBase();
myFactory.loadKnowledgeBase(kb, driver, 
"jdbc:mysql://localhost/protege", username, password, tablename, errors);
errors = new ArrayList();
prj.save(errors);

Thanks for any help in order to resolve my problem.

Regards

Olivier


The full Trace:
CONFIG: Protege 3.2.1 Build 365, JVM 1.5.0_10-b03, memory=66M, Windows 
XP, encoding=UTF-8, language=fr, country=FR
WARNING: Look and feel not found: 
com.jgoodies.looks.plastic.PlasticLookAndFeel -- 
SystemUtilities.setLookAndFeel()
CONFIG: Loaded plugin edu.stanford.smi.protegex.owl - OWL Plugin
CONFIG: Loaded plugin ca.uvic.cs.chisel.jambalaya - Jambalaya
CONFIG: Loaded plugin dfki.protege.ontoviz
CONFIG: Loaded plugin edu.stanford.smi.protege.script - Script Plugin
CONFIG: Loaded plugin edu.stanford.smi.protegex.standard_extensions - 
Graph Widget, Table Widget
CONFIG: Loaded plugin edu.stanford.smi.protege.stringsearch - String 
Search Tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.rdf_backend - RDF Backend
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.storage.rdf.configurable.RDFExportPlugin -- 
PluginUtilities.checkPlugin()
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.widget.oil.ExpressionFieldWidget -- 
PluginUtilities.checkPlugin()
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.storage.rdf.configurable.RDFCreateProjectPlugin 
-- PluginUtilities.checkPlugin()
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.storage.rdf.configurable.RDFExportProjectPlugin 
-- PluginUtilities.checkPlugin()
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.widget.oil.ExpressionListWidget -- 
PluginUtilities.checkPlugin()
WARNING: Duplicate plugin: 
edu.stanford.smi.protegex.storage.rdf.configurable.RDFCBackend -- 
PluginUtilities.checkPlugin()
CONFIG: Loaded plugin edu.stanford.smi.protegex.changes - Changes tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.pal_tabs - PAL Tabs
CONFIG: Loaded plugin edu.stanford.smi.protegex.ezpal - EZPal Tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.facets_tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.instance_tree
CONFIG: Loaded plugin edu.stanford.smi.protegex.prompt - PROMPT Tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.psm - PSM Librarian
CONFIG: Loaded plugin edu.stanford.smi.protegex.umls_tab - UMLS Tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.wordnet - WordNet Tab
CONFIG: Loaded plugin edu.stanford.smi.protegex.xml_tab - XML Tab
CONFIG: Loaded plugin edu.washington.datagenie
CONFIG: Loaded plugin org.algernon - Algernon
CONFIG: Loaded plugin se.liu.ida.JessTab - JessTab Plugin
CONFIG: Loaded plugin uk.ac.iam.soton.akt.tgviztab - TGVizTab
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.debugger
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.manchesterowlsyntaxeditor
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.owldoc
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.owlindividualstab
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.owlunittest
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.owlviz
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.protege.wizard - Basic Wizards
CONFIG: Loaded plugin uk.ac.man.cs.mig.coode.protege.wizard.owl - OWL 
Wizards
WARNING: Unable to load knowledgebase jdbc:mysql://localhost/protege -- 
java.lang.NullPointerException
    at 
edu.stanford.smi.protege.storage.database.DatabaseKnowledgeBaseFactory.initializeKB(Unknown 
Source)
    at 
edu.stanford.smi.protege.storage.database.DatabaseKnowledgeBaseFactory.loadKnowledgeBase(Unknown 
Source)