How can i read XX:MaxPermSize during runtime?

Question

Possible Duplicate:
Read Java JVM startup parameters (eg -Xmx)

We have a desktop application where some old installations does not have the appropriate memory settings.

They experience out of perm gen space at "random" times and i need to alert the users which are running too low MaxPermSize but i can't figure out how to access this setting from the jvm.

Answer 1

This should give you a rough idea on how to do it

public class Main {
    public static void main(final String[] args) {
        final RuntimeMXBean memMXBean = ManagementFactory.getRuntimeMXBean();
        final String prefix = "-XX:MaxPermSize=";
        final List<String> jvmArgs = memMXBean.getInputArguments();
        String maxPermSize = null;
        for (final String jvmArg : jvmArgs) {
            if (jvmArg.startsWith(prefix)) {
                maxPermSize = jvmArg.substring(prefix.length());
                break;
            }
        }

        System.out.println("MaxPermSize is " + maxPermSize);
    }
}