The Quarterback Java Classes Collection

The Quarterback Java Classes Collection (QJCC) is a comprehensive collection of Java classes which is used and continously developed and extended by the cantamen development divison. As it covers many common tasks, we think it to be of general interest, too. QJCC delivers among other things:

  • CSV file handling (reading from and writing into Lists of Maps)
  • Data types for dates (computation-optimized), indexed Strings, quick Arrays of int values and more
  • Helper classes for ResourceBundle to extend the Properties file concept
  • Threading stuff, including a class implementing the producer-consumer-paradigm
  • JDBC addons
  • Data model for usage of Lists of Maps in JTables
  • Cell size adjustment for JTables according to the real content of the cells. Work with every JTable.
  • New models for indexed Strings in JComboBox and JList
  • Complete configuration editor widget, configurable and localizable through ResourceBundle
  • Additional GUI classes and extensions for the MetalTheme
  • GJSA: A complete client-server framework for network-aware programs. Communication is modelled as passing of objects. Can even be used on other platforms than Java

License and Warranty

QJCC is covered by the GNU Lesser/Library General Public License (LGPL). I.e. you can use the library in your own projects, even if they are not Open Source. You must, however, republish any changes you make in the library classes themselves as source. In case of any doubt, the official documents from the FSF are authorative:

QJCC is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

QJCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with QJCC; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

Documentation and Download

QJCC is hosted on SourceForge. You can find a current version of the API documentation there, also.

Source code

The source code can be downloaded through our public git archive:

  • Repository via git protocol: git clone git://
  • Repository via HTTP: git clone
  • Web interface:

The web interface also allows to receive the source code without git ("snapshot" links in the overview on the right side).

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