通常在tomcat里配置JVM參數時，通常使用這兩個參數，
tomcat版本8.0.4；
# CATALINA_OPTS (Optional) Java runtime options used when the "start",
# "run" or "debug" command is executed.
# Include here and not in JAVA_OPTS all options, that should
# only be used by Tomcat itself, not by the stop process,
# the version command etc.
# Examples are heap size, GC logging, JMX ports etc.
# JAVA_OPTS (Optional) Java runtime options used when any command
# is executed.
# Include here and not in CATALINA_OPTS all options, that
# should be used by Tomcat and also by the stop process,
# the version command etc.
# Most options should go into CATALINA_OPTS.
大致一樣，CATALINA_OPTS里參數只能tomcat本身用，不會被stop、version命令使用。
大多數情況使用CATALINA_OPTS