How can I determine the JVM minimum heap size from within a java application?

Question

I have reviewed the answer to how to get the min and max heap size settings of a JVM from within a Java program which was helpful, but the accepted answer doesn't appear to answer half of the question. In essence, I want to report the -Xms and -Xmx settings that were used when the JVM was launched.

score 6 · Answer 1 · answered Sep 26 '11 at 18:24

6

These are the mappings between values you're looking for:

-Xmx=Runtime.getRuntime().maxMemory()
-Xms=Runtime.getRuntime().totalMemory()

Hope this helps.

answered Sep 26 '11 at 18:24

Mike K.

5

The total memory is the same as the `-ms` on startup, but might be higher after it start running. – Peter Lawrey Sep 26 '11 at 18:29

alexvetter · Accepted Answer · 2011-09-26T18:41:05.590

3

If you want to get the real JVM arguments this should help you. You can get all JVM arguments with the MXBean:

RuntimeMXBean RuntimemxBean = ManagementFactory.getRuntimeMXBean();
List<String> arguments = RuntimemxBean.getInputArguments();

You have to look for the arguments which start with "-Xm(s|x)". The problem is that the value could be something like "256M".

edited Sep 26 '11 at 18:41

answered Sep 26 '11 at 18:28

alexvetter

Perfect for my needs. We just want to log the JVM settings at start-up to provide some context when reviewing logs associated with problem reports. Thanks! – pamphlet Sep 26 '11 at 19:00

2 Answers2