Netcdf-Java library version 4.2.27 is now released at:
https://www.unidata.ucar.edu/downloads/netcdf/netcdf-java-4/index.jsp
This is mostly a bug fix and supporting changes for TDS release 4.2.9.
You are encouraged to use it for all things netCDF Java-ish.
All new development is now happening on version 4.3, for which there will be an alpha release very soon.