How to Download Java and run a file on command line

Question

I know this is SUPER basic. I am very new to all of this. I tried to download java and run a helloworld by following these instructions: https://docs.oracle.com/javase/tutorial/getStarted/cupojava/win32.html

I got an error when I tried to use the "javac" command to compile. This is what appears in the command prompt:

C:\\Users\\USer18\\Desktop>javac HelloWorldApp.java

'javac' is not recognized as an internal or external command, operable program or batch file.

Does this mean I downloaded java incorrectly? When I downloaded it, there were 3 different things to choose from, but I could only choose one, so I chose the first one. I tried to download java again and select the second one, but it said it didn't work.

Thanks in advance for helping me!

Answer 1

From the tutorial you linked, it tells you to "consult the installation instructions" found here: https://docs.oracle.com/javase/8/docs/technotes/guides/install/install_overview.html

For Windows JDK, the instructions linked are here: https://docs.oracle.com/javase/8/docs/technotes/guides/install/windows_jdk_install.html#CHDEBCCJ

The part you need to look for is "Updating the PATH Environment Variable"

Updating the PATH Environment Variable

If you do not set the PATH variable, you need to specify the full path to the executable file every time you run it, such as:

C:> "C:\\Program Files\\Java\\jdk1.8.0\\bin\\javac" MyClass.java

It is useful to set the PATH variable permanently so it will persist after rebooting.

To set the PATH variable permanently, add the full path of the jdk1.8.0\\bin directory to the PATH variable. Typically, this full path looks something like C:\\Program Files\\Java\\jdk1.8.0\\bin. Set the PATH variable as follows on Microsoft Windows:

 Click Start, then Control Panel, then System. Click Advanced, then Environment Variables. Add the location of the bin folder of the JDK installation to the PATH variable in System Variables. The following is a typical value 

for the PATH variable:

 C:\\WINDOWS\\system32;C:\\WINDOWS;C:\\Program Files\\Java\\jdk1.8.0\\bin 

Note:

 The PATH environment variable is a series of directories separated by semicolons (;) and is not case-sensitive. Microsoft Windows looks 

for programs in the PATH directories in order, from left to right.

 You should only have one bin directory for a JDK in the path at a time. Those following the first instance are ignored. If you are not sure where to add the JDK path, append it. The new path takes effect in each new command window you open after setting the PATH variable. 

Answer 2

When ever we execute any command, it is searched in the directory where we are current in or mentioned in PATH environment variable. The oly thing which you need is just add <path of yourjdk>\\bin to PATH

Windows 10 and Windows 8

• In Search, search for and then select: System (Control Panel)
• Click the Advanced system settings link.
• Click Environment Variables. In the section System Variables, find the PATH environment variable and select it. Click Edit. If the PATH environment variable does not exist, click New.
• In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.
• In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.

Windows 7

• From the desktop, right click the Computer icon.
• Choose Properties from the context menu.
• Click the Advanced system settings link.
• Click the Advanced system settings link.
• In the Edit System Variable (or New System Variable) window, specify the value of the PATH environment variable. Click OK. Close all remaining windows by clicking OK.
• Reopen Command prompt window, and run your java code.