In JDK 18, attempting to run jstatd results in the following:

$ jstatd
Exception in thread "main" java.lang.UnsupportedOperationException: The Security Manager is deprecated and will be removed in a future release
at java.base/java.lang.System.setSecurityManager(System.java:416)
at jdk.jstatd/sun.tools.jstatd.Jstatd.main(Jstatd.java:136)

The workaround is to allow setting the security manager property on the command line to allow programmatic setting of the security manager:

$ jstatd -J-Djava.security.manager=allow

Alternatively, the security manager could be enabled directly on the command line:

$ jstatd -J-Djava.security.manager

Either works, though they give different warning messages.

The property should be set by the jstatd launcher instead of requiring the user to provide it.