time since JVM started

Question

Is there a way to find out the time since the JVM started?

Of course, other than starting a timer somewhere near the beginning of main, because in my scenario I am writing library code and the requirement that something be called immediately after startup is a too burdensome.

Answer 1

Use this snippet:

long jvmUpTime = ManagementFactory.getRuntimeMXBean().getUptime(); 

or:

long jvmStartTime = ManagementFactory.getRuntimeMXBean().getStartTime(); 

This is the correct way of retrieving JVM up-time.

For more info see RuntimeMXBean

Answer 2

You can get the start time of the JVM in the following code:

import java.lang.management.ManagementFactory;   import java.lang.management.RuntimeMXBean;   ...   RuntimeMXBean runtimeMXBean = ManagementFactory.getRuntimeMXBean();   long uptimeInMillis = runtimeMXBean.getUptime(); 

See more are https://docs.oracle.com/javase/6/docs/api/java/lang/management/RuntimeMXBean.html.