Java jvm start time

time since JVM started

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.

flybywire

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In short, to get the JVM Start Time-Date you should: Get the JVM’s thread system bean, that is the RuntimeMXBean, using the getRuntimeMXBean() API method of ManagementFactory. Use getStartTime() API method to get the start time of the Java virtual machine in milliseconds.

Get Uptime JVM We can use the RuntimeMXBean class to get JVM specific information. We obtain an instance by calling the getRuntimeMXBean() method of the ManagementFactory factory class. Here, we can get the uptime java using the getUptime() method. This returns the uptime of the Java Virtual Machine in milliseconds.

2.1 Possible Causes for Slow JVM StartupThe application might be waiting to import files. A large number of methods might have to be compiled. There might be a problem in code optimization (especially on single-CPU machines). The problem might be caused by the Java application and not the JVM.

2 Answers

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

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

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

For more info see RuntimeMXBean

answered Oct 05 ’22 18:10

Yuval Adam

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.

answered Oct 05 ’22 19:10

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Java: How to Get the Start Time of a JVM ?

The ManagementFactory class is a factory class for getting managed beans for the Java platform. This class consists of static methods each of which returns one or more platform MXBean(s) representing the management interface of a component of the Java virtual machine.

An application can access a platform MXBean in the following ways:

• Direct access to an MXBean interface
  1. Get the MXBean instance through the static factory method and access the MXBean locally of the running virtual machine.
  2. Construct an MXBean proxy instance that forwards the method calls to a given MBeanServer by calling newPlatfromMXBeanProxy . A proxy is typically constructed to remotely access an MXBean of another running virtual machine.
• Indirect access to an MXBean interface via MBeanServer
  1. Go through the platform MBeanServer to access MXBeans locally or a specific MBeanServerConnection to access MXBeans remotely. The attributes and operations of an MXBean use only JMX open types which include basic data types, CompositeData , and TabularData defined in OpenType . The mapping is specified below.

Below is a simple Java Program which returns Start Time and Date of a JVM.

package com.crunchify.tutorials; /** * @author Crunchify.com */ import java.lang.management.ManagementFactory; import java.lang.management.RuntimeMXBean; import java.util.Date; public class CrunchifyGetJVMTime < public static void main(String[] args) < RuntimeMXBean runtimeBean = ManagementFactory.getRuntimeMXBean(); long startTime = runtimeBean.getStartTime(); Date startDate = new Date(startTime); System.out.println("\nStart Time in millisecond = " + startTime); System.out.println("Start Date = " + startDate); >>

Start Time = 1367269277031 Start Date = Mon Apr 29 14:01:17 PDT 2013

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Java jvm start time

The management interface for the runtime system of the Java virtual machine. A Java virtual machine has a single instance of the implementation class of this interface. This instance implementing this interface is an MXBean that can be obtained by calling the ManagementFactory.getRuntimeMXBean() method or from the platform MBeanServer method. The ObjectName for uniquely identifying the MXBean for the runtime system within an MBeanServer is:

It can be obtained by calling the PlatformManagedObject.getObjectName() method. This interface defines several convenient methods for accessing system properties about the Java virtual machine.

Method Summary

Returns the input arguments passed to the Java virtual machine which does not include the arguments to the main method.

Returns the version of the specification for the management interface implemented by the running Java virtual machine.

Tests if the Java virtual machine supports the boot class path mechanism used by the bootstrap class loader to search for class files.

Methods inherited from interface java.lang.management.PlatformManagedObject

Method Detail

getName

Returns the name representing the running Java virtual machine. The returned name string can be any arbitrary string and a Java virtual machine implementation can choose to embed platform-specific useful information in the returned name string. Each running virtual machine could have a different name.

getVmName

Returns the Java virtual machine implementation name. This method is equivalent to System.getProperty(«java.vm.name») .

getVmVendor

Returns the Java virtual machine implementation vendor. This method is equivalent to System.getProperty(«java.vm.vendor») .

getVmVersion

Returns the Java virtual machine implementation version. This method is equivalent to System.getProperty(«java.vm.version») .

getSpecName

Returns the Java virtual machine specification name. This method is equivalent to System.getProperty(«java.vm.specification.name») .

getSpecVendor

Returns the Java virtual machine specification vendor. This method is equivalent to System.getProperty(«java.vm.specification.vendor») .

getSpecVersion

Returns the Java virtual machine specification version. This method is equivalent to System.getProperty(«java.vm.specification.version») .

getManagementSpecVersion

Returns the version of the specification for the management interface implemented by the running Java virtual machine.

getClassPath

Returns the Java class path that is used by the system class loader to search for class files. This method is equivalent to System.getProperty(«java.class.path») . Multiple paths in the Java class path are separated by the path separator character of the platform of the Java virtual machine being monitored.

getLibraryPath

Returns the Java library path. This method is equivalent to System.getProperty(«java.library.path») . Multiple paths in the Java library path are separated by the path separator character of the platform of the Java virtual machine being monitored.

isBootClassPathSupported

boolean isBootClassPathSupported()

Tests if the Java virtual machine supports the boot class path mechanism used by the bootstrap class loader to search for class files.

getBootClassPath

Returns the boot class path that is used by the bootstrap class loader to search for class files. Multiple paths in the boot class path are separated by the path separator character of the platform on which the Java virtual machine is running. A Java virtual machine implementation may not support the boot class path mechanism for the bootstrap class loader to search for class files. The isBootClassPathSupported() method can be used to determine if the Java virtual machine supports this method.

getInputArguments

Returns the input arguments passed to the Java virtual machine which does not include the arguments to the main method. This method returns an empty list if there is no input argument to the Java virtual machine. Some Java virtual machine implementations may take input arguments from multiple different sources: for examples, arguments passed from the application that launches the Java virtual machine such as the ‘java’ command, environment variables, configuration files, etc. Typically, not all command-line options to the ‘java’ command are passed to the Java virtual machine. Thus, the returned input arguments may not include all command-line options. MBeanServer access:
The mapped type of List is String[].

getUptime

getStartTime

Returns the start time of the Java virtual machine in milliseconds. This method returns the approximate time when the Java virtual machine started.

getSystemProperties

MapString,String> getSystemProperties()

Returns a map of names and values of all system properties. This method calls System.getProperties() to get all system properties. Properties whose name or value is not a String are omitted. MBeanServer access:
The mapped type of Map is TabularData with two items in each row as follows:

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time since JVM started

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.

flybywire

People also ask

In short, to get the JVM Start Time-Date you should: Get the JVM’s thread system bean, that is the RuntimeMXBean, using the getRuntimeMXBean() API method of ManagementFactory. Use getStartTime() API method to get the start time of the Java virtual machine in milliseconds.

Get Uptime JVM We can use the RuntimeMXBean class to get JVM specific information. We obtain an instance by calling the getRuntimeMXBean() method of the ManagementFactory factory class. Here, we can get the uptime java using the getUptime() method. This returns the uptime of the Java Virtual Machine in milliseconds.

2.1 Possible Causes for Slow JVM StartupThe application might be waiting to import files. A large number of methods might have to be compiled. There might be a problem in code optimization (especially on single-CPU machines). The problem might be caused by the Java application and not the JVM.

2 Answers

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

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

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

For more info see RuntimeMXBean

answered Oct 05 ’22 18:10

Yuval Adam

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.

answered Oct 05 ’22 19:10

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