Question

Is there any way where I can find out which Java options are being used by a Java application inside JVM (e.g. the ones passed through the command line)?

I want to find it on the fly when the application is running, but from outside outside the application.

Answer 1

You can use JMX:

final JMXConnector connector = JMXConnectorFactory.connect(new JMXServiceURL(connectorAddress));
final MBeanServerConnection mBeanServerConnection = connector.getMBeanServerConnection();
final ObjectName commandLine = new ObjectName("java.lang:type=Runtime");
final List<Attribute> arguments = mBeanServerConnection.getAttributes(commandLine, new String[] {"InputArguments"}).asList();
String[] inputArguments = (String[]) arguments.get(0).getValue();
System.out.println(Arrays.asList(inputArguments));
connector.close();

To get the JMX connection, you might find my answer to ” JMX client accessible locally only ” helpful.