Is it possible to get the command used to launch the jvm in java?

Question

I would like to know if it is possible to get from code the command used to launch a java program.

E.g. if I launch a java program with:

 java -cp lib1:lib2:... -jar mylib.jar com.foo.Bar

I would like to get the exact string (jvm parameters included).

Is it possible?

Comment on the bounty and the question

Thank you all for your responses. Unfortunately, I did not get the answer I was initally looking for. I was hoping there was some portable solution to get the complete java command from within the program itself (including classpath etc.). As it seems there are no portable solution and since I am using Linux I am using the responses of agodinhost and Luigi R. Viggiano to solve my problem. However I give the bounty to rahulroc for the most complete (portable) response. For the rest an upvote for all :)

@SubinS It will execute the OS command through java. He want to get that command used in command prompt. — Smit, Dec 19 '12 at 18:05
are you looking to get the command from within the running program? — akf, Dec 28 '12 at 11:57

score 27 · Answer 1 · edited Jul 30 '16 at 22:46

The below mentioned code should show all JVM parameters, arguments passed to the main method as well as the main class name.

import java.lang.management.ManagementFactory;
import java.lang.management.RuntimeMXBean;

import java.util.List;

public static void main(String[] args) {
  RuntimeMXBean bean = ManagementFactory.getRuntimeMXBean();
  List<String> jvmArgs = bean.getInputArguments();

  for (int i = 0; i < jvmArgs.size(); i++) {
    System.out.println( jvmArgs.get( i ) );
  }
  System.out.println(" -classpath " + System.getProperty("java.class.path"));
  // print the non-JVM command line arguments
  // print name of the main class with its arguments, like org.ClassName param1 param2
  System.out.println(" " + System.getProperty("sun.java.command"));
}

javadoc for 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.

You can also take a look at : jps

It's a Java program that is able to get the full command line for all Java processes, including full class name of main class and JVM options.

You can find a good summary of various JVM tools, including Java Application Launcher links to :

ManagementFactory.getRuntimeMXBean() - Returns the managed bean for the runtime system of the Java virtual machine.
getInputArguments() javadoc
determine if JVM is running in debug mode

"determine if JVM is running in debug mode" the link is dead but the relevant code in the article was `List inputArgs = ManagementFactory.getRuntimeMXBean().getInputArguments(); if (!inputArgs.contains("-Xdebug"))` - so it's not very relevant since Java 5. — Vsevolod Golovanov, Dec 05 '17 at 15:48

score 19 · Answer 2 · edited May 06 '15 at 12:47

You can use this to retrieve the VM parameters :

public static void main(String args[]) {
    List<String> inputArguments = ManagementFactory.getRuntimeMXBean().getInputArguments();
    System.out.println("input arguments = " + inputArguments);
}

However it won't give you all the command line (only gives the JVM arguments, no main class nor parameters). Sample output:

input arguments = [-Dfile.encoding=UTF-8, -XX:-UseTLAB, -Xms2000m, -Xmx2000m, -XX:+PrintCompilation, -XX:+PrintGC]

score 8 · Answer 3 · edited May 23 '17 at 11:47

8

It only works on ~~Sun~~ Oracle JVM: System.getProperty("sun.java.command")

Additionally, you can have a look at JavaSysMon, it can report command line of active processes. To check which is the current JVM Process check here: How can a Java program get its own process ID?

edited May 23 '17 at 11:47

Community

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answered Dec 28 '12 at 01:36

Luigi R. Viggiano

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Sorry, does not work; modding-down. Apologies for the (lack of) formatting: `$ java -showversion -classpath toys/ -Xms16M -Xmx20M Env | grep command java version "1.7.0_09" Java(TM) SE Runtime Environment (build 1.7.0_09-b05) Java HotSpot(TM) 64-Bit Server VM (build 23.5-b02, mixed mode) ` *sun.java.command=Env* Env is a simple Java program to dump system properties to standard output. – Christopher Schultz Dec 28 '12 at 16:38

score 8 · Answer 4 · answered Dec 28 '12 at 11:52

8

in a linux machine would be easier to run:

ps -ef | grep java

this command will list all java programs running with it's used parameters.

Not sure about what can be used in a windows environment.

answered Dec 28 '12 at 11:52

agodinhost

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This is possibly the equivalent on Windows: http://stackoverflow.com/questions/9589431/getting-the-command-line-arguments-of-another-process-in-windows – assylias Dec 30 '12 at 14:07

score 6 · Answer 5 · answered Jan 03 '13 at 17:22

6

In the task manager on Win2003 you can enable the display of a column that displays the command like it does on linux. Or, you can do it from the command line like so:

wmic.exe PROCESS where "name like '%java%'" get Processid,Caption,Commandline

answered Jan 03 '13 at 17:22

djangofan

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Can you print a sample output? – Sam Dec 27 '22 at 23:49
This is an old comment. Looks like it's not working on Windows11. – djangofan Jan 06 '23 at 02:10

Is it possible to get the command used to launch the jvm in java?

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