Something like this doesn't exist now AFAIK but you can use the jvm's mxbeans to get this data I should probably add it to my tools.jvm library

https://docs.oracle.com/en/java/javase/17/docs/api/jdk.management/com/sun/management/UnixOperatingSystemMXBean.html#getOpenFileDescriptorCount()

since this is abundant and constantly-changing data, a profiler will show it in a particularly usable manner I use YourKit (for other reasons), it's a premium product which as every xmas, you will find for a nicer price