Currently the only way to configure grizzly-sendfile is to specify JVM properties, which are then parsed by the default contructor of SendfileConfig. This is very inflexible and forces grizzly-sendfile-server to use some pretty ugly code to allow users to specify options via CLI arguments. Ideally the SendfileConfig should use the builder pattern to make it easy to create the config file, set defaults and enforce object immutability once the construction is complete.