現在遇到一個 linux 的 fd（開檔數量）過多造成的的系統問題。所以需要一個 java sample code 來 monitor current file.
On unix one way is using the ManagementFactory to get the OperatingSystemMxBean and if it is a UnixOperatingSystemMXBean you can use getOpenFileDescriptorCount() method.
Example Code below
import java.lang.management.ManagementFactory;
import java.lang.management.OperatingSystemMXBean;
import com.sun.management.UnixOperatingSystemMXBean;
public class OpenFileCount{
public static void main(String[] args){
OperatingSystemMXBean os = ManagementFactory.getOperatingSystemMXBean();
if(os instanceof UnixOperatingSystemMXBean){
System.out.println("Number of open fd: " + ((UnixOperatingSystemMXBean) os).getOpenFileDescriptorCount());
}
}
}