To do the same, open Command Prompt and then run the following command to check which version of Java is installed on your computer.

But these aforementioned Java command-line tools -- namely, javac, javap, jstat, jdeps and jar -- are the five that serious software developers need to know.

At the command prompt, type “java -version” (again, no quotes). Users also can visit Java.com and click the “Do I have Java?” link on the homepage.