Knowledge Base

Notice Information in this article applies to Excelsior JET versions 3.5 through 3.7. For version 4.0 and above, see article #24.


A JET-compiled application does not print stack backtrace to standard output when an uncaught exception is thrown by one of its threads or when a printStackTrace() method is called explicitly.


By default, stack trace printing is disabled in the JET runtime system (Throwable.printStackTrace() methods do nothing.)


To enable stack trace, set the jet.stack.trace system property, for instance:

  SET JETVMPROP=-Djet.stack.trace

Using the Control Panel, you may specify the property on the Target page: type jet.stack.trace in the System Properties field and recompile the application.

Note: Enabling stack trace may negatively impact performance, if exceptions are thrown and caught repeatedly.

The jet.stack.trace setting enables printing stack traces that contain only class names. If you need a detailed information including method names and line numbers, add this option


to the beginning of the project file and recompile your application.

Note: The side effect of setting GENSTACKTRACE ON is the substantial growth (20% or more) of the resulting executable size.


  1. Excelsior JET User’s Guide (, Chapter “Application considerations”, section “System properties”.
  2. Excelsior JET User’s Guide (, Chapter “Application considerations”, section “Stack trace”.

Article ID: 15
Last Revised On: 26-Sep-2005