Project guidelines:

Get it running

To get gnowsis running in development mode, do the following.


Java 1.5 You need Java 1.5. And we would recommend you download the SDK, not the JRE.

Eclipse We recommend to use the Eclipse SDK for Java development of gnowsis. Our developers are using Eclipse 3.1.0 at the moment, this proved to be a good choice. You can use 3.2, it should also work. The following plugins are good to have and are used by use:

After getting eclipse running and having your subclipse installed, you then checkout the current version of gnowsis.


on MacOS it is wise to install JavaHL additionally, this is used by Subclipse, and subclipse will die if it is not there. get metissian containing javahl here.

getting the code

The subversion repository is

There you check out these projects, the most important projects to check out are:

  • gnowsis - starter
  • gnowsis-server - core
  • enquire2006 - gui
  • kaukoluwiki - the semantic kaokolu wiki
  • sesame1 - web api for gnowsis

SVN problems

Use Eclipse 3.1 with Subclipse 0.9.105 on Windows. Then it has to work, as Leo develops this way. It should work on all operating systems using any SVN client, though.

Note: If you get this error: Unable to access https://...., unable to access site ...., PKIX path building failed: ...PathBuilderException: unable to find valid certification path to requested target then you probably didn't say "yes" when you where asked this: Error validating server certificate for - Unknown certificate issuer Fingerprint: 57:23:96:60:c7:4e:4b:04:8a:9a:a1:1e:02:59:8a:11:52:0c:6e:97 Distinguished name:, Root CA. So, to fix this, you can either press "Accept permanently" in the right moment or look in this directory for more: <yourhome>\Application Data\Subversion\auth

If you want to do Aperture development:

  • Aperture in CVS: cvs login
    • host:
    • repository path: /cvsroot/aperture
    • connection type: pserver
    • username: anonymous
    • password: empty
  • Checkout project aperture

Getting it to start

The gnowsis project has the launcher for you.

  • If you have gnowsis checked out - the "run..." menu should have a list of favourites:
    • Windows start gnowsis
    • MacOSX start gnowsis
  • The GnowsisInstaller will show. satisfy it.
  • pressing close. gnowsis installs now silently. stand up, take a breath. think of something positive. notice the new simplicity. tell somebody a nice thing. sit down again.

Note: If above options do not show up in the "run" menu, then Eclipse has hickups. We then usually open the "navigator" view, go to the "gnowsis" project and double-click all "*.launch" files. That opens the launch files in the text editor and tells eclipse that the launch configurations exist. Then the launch files are available in the long list you see at "run...". Start gnowsis there using the Windows start gnowsis launch configuration (or alternative). After you have done this once, Eclipse will know and the launcher will be in your favorites.

Understanding gnowsis

  • Understanding Gnowsis read this document to know more about the parts of gnowsis and how they work together.


Use Eclipse debugger to debug.

To set the general log level in gnowis, do that:

open .gnowsis-beta/config/workspace.xml

change this line:
allowed levels are all java.util.logging.Level levels: SEVERE, WARNING, INFO, FINE, FINER, FINEST

Individual logging levels are set in this file:


# add this to bottom
# set the loglevel of a specific package
de.opendfki.kaukoluwiki.level = FINER

Specific Fields of Development



The first thing you might want to do is to write your own datasource, Gnowsis can deploy your own datasources without having to change the gnowsis code: See DynamicDatasources for more information! Also, you may be interested to improve gnowsis and help fixing broken code, look at bugtracker: report:1. Then JoinGnowsis.

Last modified 18 years ago Last modified on 10/30/06 13:33:22