SAC - crotwell/seisFile GitHub Wiki
SeisFile supports both reading of binary SAC datafiles, as well as poles and zeros. SAC file related code is in the edu.sc.seis.seisFile.sac package.
SacTimeSeries sac = new SacTimeSeries(filename);
or
DataInput dis = ...
SacTimeSeries sac = new SacTimeSeries(dis)
and reading a polezero file:
SacPoleZero spz = new SacPoleZero(filename);