RT-10974 provides access to application parameters at the Application level with Application.getParameters(). However, there is no good way to access these parameters from within the FX runtime libraries. One application of using launch parameters in the libraries is to log launchTime to the PerfLogger for applet startup testing (PERF-94).

PERF-132 updated the launch time logging code, but it's not an ideal solution. For instance, custom parameter handling code was added on the deploy side, instead of the code being isolated to the PerformanceTracker. A more desirable fix for PERF-132 could be written if we had parameter access from the library level.

This could be provided either directly (e.g. ParametersImpl.params.getAll()) or indirectly via access to an Application object (e.g. Application.getCurrentApplication() -> theApp.getParameters()).

It seems to me a non-public method would be sufficient - application developers already have access to their own Application object.