监控项目，资源。

• https://docs.oracle.com/javase/1.5.0/docs/api/java/lang/management/MemoryMXBean.html

• https://juejin.im/post/5acf4f936fb9a028e46f085e

• https://docs.oracle.com/javase/7/docs/jre/api/management/extension/com/sun/management/GarbageCollectionNotificationInfo.html

• http://hllvm.group.iteye.com/group/topic/38227

• https://www.ibm.com/developerworks/cn/java/j-rtm1/

• init / used / committed / max 内存状态描述

• https://docs.oracle.com/javase/9/docs/api/java/lang/management/MemoryUsage.html