Mac10.5之后jvm设定信息

mac os 自10.5之后 使用 /usr/libexec/java_home 来查询系统的jvm信息（oracle打包安装的）

/usr/libexec/java_home --help
Usage: java_home [options...]
Options:
[-v/--version ] 根据给的版本过滤
[-a/--arch ] Filter JVMs matching architecture (i386, x86_64, etc).
[-d/--datamodel ] Filter JVMs capable of -d32 or -d64
[-t/--task ] Use the JVM list for a specific task (Applets, WebStart, BundledApp, JNI, or CommandLine)
[-F/--failfast] Fail when filters return no JVMs, do not continue with default.
[ --exec ...] Execute the $JAVA_HOME/bin/ with the remaining arguments.
[-R/--request] Request installation of a Java Runtime if not installed.
[-X/--xml] Print full JVM list and additional data as XML plist.
[-V/--verbose] Print full JVM list with architectures.
[-h/--help] This usage information.