The JVM id is only internally available and cannot be accessed using normal Java methods.
Java 1.4 and higher
Make use of System.getProperties(). But this does not provide any unique identification of a JVM!
java.runtime.name: Java(TM) SE Runtime Environment java.vm.version: 14.1-b02 java.vm.vendor: Sun Microsystems Inc. java.vendor.url: http://java.sun.com/ java.vm.name: Java HotSpot(TM) Server VM java.vm.specification.name: Java Virtual Machine Specification java.runtime.version: 1.6.0_15-b03 java.awt.graphicsenv: sun.awt.X11GraphicsEnvironment java.endorsed.dirs: /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/endorsed java.io.tmpdir: /tmp java.vm.specification.vendor: Sun Microsystems Inc. java.library.path: /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/server:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/../lib/i386:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386/client:/usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/i386:/usr/lib/xulrunner-addons:/usr/lib/xulrunner-addons:/usr/java/packages/lib/i386:/lib:/usr/lib java.specification.name: Java Platform API Specification java.class.version: 50.0 java.awt.printerjob: sun.print.PSPrinterJob java.specification.version: 1.6 java.class.path: /home/bugsy/working/projects/NovaSpy/workspace/Test/bin java.vm.specification.version: 1.0 java.home: /usr/lib/jvm/java-6-sun-1.6.0.15/jre java.specification.vendor: Sun Microsystems Inc. java.vm.info: mixed mode java.version: 1.6.0_15 java.ext.dirs: /usr/lib/jvm/java-6-sun-1.6.0.15/jre/lib/ext:/usr/java/packages/lib/ext java.vendor: Sun Microsystems Inc. java.vendor.url.bug: http://java.sun.com/cgi-bin/bugreport.cgi
For Java5:
Use Java Management to retrieve the start time of the JVM
ManagementFactory.getRuntimeMXBean().getStartTime()