For an introductory Java class I am taking, I installed the Eclipse integrated development environment (IDE) on a Microsoft Windows 10 system. In addition to compiling and running Java programs through the IDE, though, I wanted to compile Java programs using the Java compiler, javac.exe, and run them using java.exe from Windows' command-line interface (CLI). The installation process for Eclipse installed the javac.exe and java.exe executables in a user directory with a long directory path to those executables. Note: you should install the Eclipse IDE from the account which you wish to use to compile and run java programs. The location wasn't added to the path environment variable, so if you try to run the programs from a command prompt, you will see the following, unless you specify the full path name where the executable files are located.
C:\Users\Jim>java 'java' is not recognized as an internal or external command, operable program or batch file. C:\Users\Jim>javac 'javac' is not recognized as an internal or external command, operable program or batch file. C:\Users\Jim>
I didn't want to have to copy and paste the full path on the command line
or type it in every time I wanted to use the two executables from the
command line. To avoid that problem you can add the directory path to the
path environment variable through a set path= command or create
another environment variable, e.g., JAVA_HOME that points to the directory
where the two files are located, though both methods apply only to a particular
command line instance. I.e., if you close a command prompt window where you've
set one of the variables to include the location where Eclipse installed
java.exe and javac.exe then open another command prompt window, you will have
to set the environment variable again in the new instance. An alternative
way to make a permanent path change from a command prompt interface is to use
the Windows setx command, though I would not recommend it, since if
your path variable already has a path that is more than 1,024 characters long,
setx can truncate the path to 1,024 characters, so that you not only don't
get the additional directory added to the path, but you may lose some of
the path setting you had prior to issuing the command. If you want to
make a permanent change, see responses to the
"Overcoming the 1024 character limit with setx"
posting at the superuser.com site.
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