On 24/07/2015 10:12, Ron Pressler wrote:
OK, but assuming I have no control over the user's runtime image, am I
correct that programmatically starting the local JMX agent as I do now
(without the Attach API) will no longer be possible in Java 9?
I'm not aware of any supported way of doing this in any JDK release, at
least not without using Runtime.exec or ProcessBuilder to invoke the
jcmd tool which might or might not be present.
If you have code making direct use of JDK-internal classes such as
sun.management.Agent then it fail at both compile-time and run-time with
JDK 9 once the module system goes in. There will be a command-line
option to work around this but no guarantees of course as
sun.management.Agent might not exist, might be refactored significantly,
etc.
You probably know this already but you can start your own
JMXConnectorServer if you want. Also you don't need the JMX agent to
access the platform MXBeans in the current runtime.
As regards tools using the attach API then then moving them to modules
means they can have an explicit dependency on the jdk.attach module.
This is good because it means they won't even start on a run-time that
doesn't the jdk.attach module. Also if you get to create your own
run-time image and want to include one or these tools then it will
ensure that the jdk.attach module is also linked in.
-Alan
