If you have Sun Microsystem's Java Runtime Environment (JRE) installed on a system, you can check its version by obtaining a command prompt and entering the command
java -version.
C:\>java -version java version "1.6.0_07" Java(TM) SE Runtime Environment (build 1.6.0_07-b06) Java HotSpot(TM) Client VM (build 10.0-b23, mixed mode, sharing)
If you selected the default install directory, the JRE software will likely
be stored in C:\Program Files\Java.
C:\PROGRA~1\Java>dir
Volume in drive C has no label.
Volume Serial Number is AC89-88C6
Directory of C:\PROGRA~1\Java
08/02/2008 08:55 AM <DIR> .
08/02/2008 08:55 AM <DIR> ..
11/20/2004 04:49 PM <DIR> j2re1.4.2_03
12/13/2004 02:57 AM <DIR> j2re1.4.2_05
08/15/2005 09:20 PM <DIR> jre1.5.0_04
01/12/2006 12:57 AM <DIR> jre1.5.0_06
08/02/2008 08:55 AM <DIR> jre1.6.0_07
0 File(s) 0 bytes
7 Dir(s) 54,967,054,336 bytes free
On a Linux system, you can also issue the java -version command
to see the version.
$ java -version java version "1.4.2" gij (GNU libgcj) version 4.1.2 20071124 (Red Hat 4.1.2-42) Copyright (C) 2006 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
