jtai

import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import java.lang.reflect.Method;

class Descriptors {
    public static void main(String [ ] args) {
        OperatingSystemMXBean osMxBean = ManagementFactory.getOperatingSystemMXBean();
        try {
            Method getMaxFileDescriptorCountField = osMxBean.getClass().getDeclaredMethod("getMaxFileDescriptorCount");
            Method getOpenFileDescriptorCountField = osMxBean.getClass().getDeclaredMethod("getOpenFileDescriptorCount");