jvm specification（JVM args 规格严格）

This technique takes advantage of Platform MXBeans available since J2SE 5 (custom MXBeans support was added in Java SE 6).

Two useful sources of information on the JVM parameters available when using Suns JVM are:

A Collection of JVM Options and Charles Nutters Favorite Hotspot JVM Flags.

Both of these resources list and describe some/all of the not-recommended-for-the-casual-developer double X arguments (-XX) that are available.