Which JRE am I using?

The following command will tell you a lot of information about your java version, including the vendor:

java -XshowSettings:properties -version

It works on Windows, Mac, and Linux.

 System.out.println(System.getProperty("java.vendor"));
 System.out.println(System.getProperty("java.vendor.url"));
 System.out.println(System.getProperty("java.version"));

 Sun Microsystems Inc.
 http://java.sun.com/
 1.6.0_11

http://docs.oracle.com/javase/tutorial/essential/environment/sysprop.html

1. Open up your:
   • command prompt if you're using Windows
   • terminal if you're using mac or Linux

2. Type in:

   java -version // This will check your JRE version
   javac -version // This will check your Java compiler version if you installed the JDK
   

3. Grab a cup of coffee and you're done! You don't need to add the .exe to the java -version if everything is installed correctly.