「每天一道面试题」如何用代码查看JVM中堆和非堆的使用情况？

MemoryMXBean memoryMXBean = ManagementFactory.getMemoryMXBean();

System.out.println(memoryMXBean.getHeapMemoryUsage());

System.out.println(memoryMXBean.getNonHeapMemoryUsage());