Develop Reference

Run jps on command promt

I installed Hadoop and tried to run it. The terminal shows that everything has been started but when I run jps command it shows :
'jps' is not recognized as an internal or external command,
operable program or batch file.
I set JAVA_HOME= C:\Progra~1\Java\jre1.8.0_261 and path = C:\Progra~1\Java\jre1.8.0_261\bin and C:\Program~1\Java\jre1.8.0_261\legal\jdk in enviroment, but when I type jps in command prompt it shows : Not recognized as an internal or external command.
I don't know what can I do, Help me, please.

It looks like the jps executable is no present in the bin directory that you've specified in system environment variable. It should be inside C:\Program Files\Java\jdk1.8.0_261\bin if you have jdk1.8.0_26 installed in your system in the location C:\Program Files. Try specifying the JAVA_HOME like this:
Go to Control Panel -> System -> Advanced System Settings -> Environment Variables.
Add a new path variable called JAVA_HOME:
JAVA_HOME=C:\Program Files\Java\jdk1.8.0_261
Select Path from System Variables and click Edit.
Remove the existing Java path and add the new path as %JAVA_HOME%\bin
Now, open command window, type jps and hit ENTER.
Note: You can download JDK from here

Javac not recognised even after setting variable path, Windows 10?

I'm getting an error when typing javac in command prompt.
C:\Users\HP>javac
javac is not recognized as an internal or external command, operable program or batch file.
C:\Users\HP>set path
path=C:\Program Files\Java\jdk-10\bin;C:\Program Files\Java\jre-10\bin\javaw.exe;C:\Program Files\Java\jdk-10\bin;C:\Program Files\Java\jre-10\bin;
PATHEXT=C:\Program Files (x86)\Documents;
I have already set Path in both system and user scope environment varible?

You may set 2 system variable from console:
set JAVA_HOME="c:\Program Files\Java\jdk1.8.0_144"
set PATH=%JAVA_HOME%\bin;%PATH%
then your command "javac" will be found.

The PATH variable looks corrupted. Moreover, the PATHEXT variable is totally confused. Their default value in Windows 7/10/2008 (assuming the system drive is C:) should be as follows:
PATH C:\Windows\System32\;C:\Windows\;C:\Windows\System32\Wbem;{plus program paths}
PATHEXT .COM; .EXE; .BAT; .CMD; .VBS; .VBE; .JS ; .WSF; .WSH; .MSC
Check output from SET PATH in a freshly open cmd window. If path and pathext look as above then use (modify directory names to match current Java version):
set "JAVA_HOME=C:\Program Files\Java\jre-9.0.4"
set "PATH=%JAVA_HOME%\bin;%PATH%"
Above setting is temporary (would last only for current cmd session). For persistent solution, there are more tutorials on the net e.g. How To Set Java Path & Java Home Variables (Windows, MacOS, Ubuntu).

Try out the following solutions.
Close your current cmd and Open a new cmd.exe
Restart the computer
NOTE: If cmd is open when you set the environment variables, then, that property will not be available until unless you open new cmd.

On Windows 10, the problem of 'javac is not recognized ...' can be fixed in these 4 steps:
Step 1: Install JDK to specific path (Example: C:\jdk-15)
Step 2: Setup JAVA_HOME environment variable to the installation folder
Windows --> Advanced settings --> Environment variables --> System Variable
--> Add new variable
JAVA_HOME = C:\jdk-15
Step 3: Prefix JAVA_HOME\bin to PATH variable of Windows
Windows --> Advanced settings --> Environment variables --> System Variables
--> Update PATH variable
PATH = JAVA_HOME\bin;..... old value of PATH variable ....
Step 4: Try the javac and java commands in new command window
Note: Already opened command windows will not take the new values of JAVA_HOME or PATH. The test needs to be done in new window opened after the environment variables are changed and saved.
C:\Users\user1> javac -version
C:\Users\user1> java -version

java path is not set when add path field in environment variables

I am new to java programming language. First i download the sdk and install it in to my pc.
Then i add a new environment variable like this
path C:\Program Files\Java\jdk1.6.0_29\bin
After creating this i entered javac in my cmd prompt. But i didn't get any thing.
'javac' is not recognized as an internal or external command.
operable program or batch file.
i am look in to some tutorials they said this way for setting path. if any one know about this please help me.

Right click My Computer -> Advance Options -> Environment Varibles -> Under User Variables
Click New
Under Variable name type JAVA_HOME
Under Variable value type C:\Program Files\Java\jdk (without bin)
Click OK
Again Click New
Under Variable name type PATH
Under Variable value type %JAVA_HOME%\bin
Click OK

1. Right click My Computer->Advence Option->Environment Varibles->SystemVariables
2. variable : Path->Edit
3. Copy your jdk bin directory i.e. C:\Program Files\Java\jdk1.6.0_29\bin
4. Paste it after putting a semi-colon(;) in value section
To test it..Open cmd with administrator and type java -version

Follow this Step for Windows for Permanent Path setup:
1) My Computer Properties
2) Advanced Option
3) Environment Variable
4) New tab
5) Name= Path
6) Value = C:\Program Files\Java\jdk1.6.0_29\bin
7) Ok
EDIT
See that you are into c:\Windows\System32 and your admin
That's IT now type javac and its DONE

Assuming your jdk is installed in c:\Program Files\java\jdk directory
EDIT "Path" system variable
which would be --> C:\WINDOWS\SYSTEM32
To -->
C:\WINDOWS\SYSTEM32;c:\Program Files\java\jdk\bin

Javac Command Not Working

My javac command is not working.
"javac is not recognized as an internal or external command, operable program or batch file."
-java version WORKS
I've tried setting classpath successfully in command prompt. SET CLASSPATH "C:\Program Files\Java\jdk1.7.0_09\bin";
Ive adding it in environment variables. ;C:\Program Files\Java\jdk1.7.0_09\bin ;C:\Program Files\Java\jre7\bin
Ive checked the bin folder java.exe is there aswell as javac.exe.
^ Tried all of these still doesn't work. I've also restarted command prompt still does not not work.
Why is not working?

You're using the correct path apparently, but you should assign it to the PATH variable, not to the CLASSPATH variable.
You're trying to set the access path to the executable files, not to the class files.

Just do this
In the same dialog, make sure that JAVA_HOME exists in your user variables or in the system variables and it is set to the location of your JDK,
e.g. C:\Program Files\Java\jdk1.5.0_02 and that %JAVA_HOME%\bin is in your Path environment variable.

Just set JAVA_HOME to
C:\Program Files\Java\jdk1.7.0_09

After adding the path to the jre7\bin-Folder to the PATH-Variable, you need to restart your Computer in most cases.

Did you tried to create a JAVA_HOME variable? The value should be the path of the java without the bin.
Also, try to open Eclipse.
If nothing helps, the last thing that you can do is install netbeans, it will configurate everything.

Problems with ANT installation

Please excuse my french english ^^
I have got a probleme with the ANT installation...
I've download the ANT Zip on the apache website
I've set the environment variable ANT_HOME to : C:\Program Files\apache-ant-1.8.4
I've set the environment variable JAVA_HOME to : C:\Program Files\Java\jdk1.7.0_07
I've add, in the PATH variable : C:\Program Files\apache-ant-1.8.4\bin
But when I want to test the "ant" or "ant -version" command in the CMD, I've have got this error : (in french for me :P, I have translate for you :D)
“ant” is not recognized as an internal or external command, operable program or batch file.
Have you got an idea ?
I have to install this program to use "zxing" on Android :)
Thanks !

Change in the PATH environment variable are not applied on opened command line.
If you just changed the PATH, you need to open a new command line terminal. You can check by typing echo %PATH%.