time since JVM started
JavaTimeJvmJava Problem Overview
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.
Java Solutions
Solution 1 - Java
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
Solution 2 - Java
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.
Solution 3 - Java
if your jvm program running in linux, you can view the startTime use ps
ps -p <pid> -o stime,etime
Solution 4 - Java
Starting from Java 5, you can use JMX to find this out. Check "Using the platform MBeanserver" to find out more details. The bean you're looking for is the bean called "java.lang:type=Runtime". The attribute StartTime gives you the time the JVM was started and the Uptime attribute tells you the uptime of the JVM.
You can get a reference to the Runtime bean by executing this code:
ManagementFactory.getRuntimeMXBean();
Solution 5 - Java
Perhaps worth mentioning that if you don't want to write any code run up jconsole from the java bin directory and click VM Summary and see the Uptime and Process CPU time values.