I can not set up CVX on my computer after I had tried to do following way in website of CVX

Dear all,
Can you help me for installing CVX. I had tried to install same direction but it appears error as:
UNEXPECTED ERROR: ----------------------------------------------
Undefined function ‘usejava’ for input arguments of type ‘char’.
Error in cvx_version (line 89)
if isoctave || ~usejava(‘jvm’),
Error in cvx_setup (line 20)
cvx_version( ‘-install’, varargin{:} );
Please report this error to support, and include entire output of
CVX_SETUP in your support request.

I’m having the same problem as well. How can I solve the problem?