Develop Reference

Java commands flash a cmd

I'm new to Java. I already installed Java, JDK and added it to Path, but when I try to run a command (like "java -version") it just flashes a CMD but doesn't show what I want to see. This happens with every command and doesn't even let me run Java code using an IDE. There is no error message, just a CMD flashing every time I try to run something (it also happens when double click the files like "java", "javac", etc).

How do you run these commands? Try running them from an interactive terminal window. Open it by typing windows key + R and then cmd. Then cd into your directory and type your commands there. Alternatively, if your commands are in a .bat file … you may add a pause command at the end.

This is entirely expected as java -version immediately exits after printing the version. This means that if you didn't start it from cmd, PowerShell, or another interactive shell, it opens a window which disappears immediately because the program ended in a fraction of a second.
Start cmd (Command Prompt) or PowerShell (either directly or through Windows Terminal), and run your commands in that interactive shell.

Keeping terminal open when running a bash script from a desktop shortcut

I am running a bash script from my desktop off of a shortcut I made for it. When I click on it it says "Execute in Terminal" which is the option I want to do. The bash script compiles and runs a java program I made and the point of the script is to handle the errors that the program may through through the compiling prosses to someone who has very little programming experience (not really important to the question though). When I launch it, it will open the terminal as expected. When it encounters the error it will print out the error to the screen as one would expect it to do but then will immediately close the terminal it opened.
What I want is for the terminal to stay open until someone exits the terminal so they can read the errors.

I suggest you to add a line of code at the end of your bash script with a read operation as follows:
read -p 'Hit ENTER to exit'
This will keep the terminal visible until you hit ENTER.

creating a bat file which sends to background and closes (1 file)

im trying to do something simple, i want to start Burp Suite with extra java memory, but i don't want the CMD window to stay open.
If i don't use a .bat file and simple open cmd and type start /b "" java -jar -Xmx2g burpsuite_pro_v1.6.07.jar, Burp opens, the the process is sent to background, but the CMD window stays open. i can, however, close it manually and Burp will keep working.
when i try to put the thing into a CMD window, it will not even be sent to background, Burp stays dependent on the CMD, and i cant even add exit to the file.
i tried to solve the issue by following:
run bat file in background - this worked, but required me to have THREE files, i prefer a more elegant "1 file solution"

Just add the below line in your bat file and the java procees will run in background with no window open!
start javaw {Path of Your jar or Java file}

The following batch file commands should accomplish your purpose:
start "" /B java.exe -Xmx2g -jar burpsuite_pro_v1.6.07.jar
exit
You can probably even leave out the /B switch.
References
How can I run a program from a batch file without leaving the console open after the program start?
How to use the start command in a batch file?

Turns out the solution was simple: using javaw.
the issue was with using java.exe, some attempts even closed the CMD but opened a java.exe window (blank)
modding the file to contain:
start javaw -Xmx2g -jar burpsuite_pro_v1.6.07.jar solved it for me.

Executing .bat files using jenkins

I'm trying to run a jar file using a bat command with jenkins. and I want to popup the cmd and execute the jar file. but the problem is jenkins execute commands inside its console. Then i inserted "start" command and hoped it'll work coz it creates a separate cmd to run the jar.
here is my bat code
start "window_name" java -jar myjarfile.jar
but when i executing using it jenkins it doesn't create a separate cmd window but it executes the jar file anyhow. it shows this line,
C:\Update>start "window_name" java -jar myjarfile.jar
any idea how to solve this? I want to pop up a black window when executing.

The trick is figuring out in what session you want to start the cmd.exe. On a remote server (which is most often the case with Jenkins), it's not necessary straight forward. Your Remote Desktop Session is not in the same session as someone who is logged in physically at the console.
Bring up Windows Task Manager
Click the Users tab
Note down the ID of the session of the logged in user that you want
Download psexec from Windows Sysinternals
Edited from here downwards
Open elevated command prompt: type cmd into Start's quicksearch, right click cmd.exe, select Run as Administrator.
Type C:\path\to\psexec.exe -accepteula and press enter.
Type C:\path\to\psexec.exe -i 1 cmd and press enter. (If you see a command prompt appear, all is good, close it now)
In Job configuration, configure Execute Windows Batch command step
Write the following:
C:\path\to\psexec.exe -accepteula && C:\path\to\psexec.exe -i 1 cmd /c start C:\full\path\to\java.exe -jar myjarfile.jar
A more detailed explanation is provided in this answer Open Excel on Jenkins CI

Thanks Guys, May be your solutions too will do the trick. Finally what I did is i created a socket program and executed server myself. Then scheduled jenkins to execute the client.(Server in my environment & client in jenkin's environment) When client connects to the server it executes the bat file. Now everything works fine.

closing a command line window in Java

I have created a small Java application in which there is some code that executes a batch file. The execution of the batch file leads to the command line window to be opened and to display some output messages. I would like to know if there is some way in Java to call this command line window to be closed from within the program...Thanks!

the command window should close automatically when the batch file completes.
and to run a batch file in background/invisibly, check other questions

Start java by using javaw or javaw.exe.
java (java.exe) runs with an associated console window,
javaw (javaw.exe) is the same but without the console window.
see the documentation for the java command.
On Windows also use start to invoke another shell
start javaw ClassName
I'm not sure for Linux&Co. Try using an & after the command to run it in the background
javaw ClassName &
The other way, closing the window from a batch started by Java:
I don't believe that is possible directly from within Java. You can only close the batch file by itself.
Is hard to help without knowing what that batch file is doing. You may try using the start command on windows or the & in Linux to run the process in the background (start has an option to open the window minimized [/MIN] or in the background [/B]).
Or try some hack like using AutoHotKey or some system functionality (some WinAPI-DLL or equivalent in other systems).

As an addition to NimChimpsky's answer:
If you run a batch file in Windows, Windows will automatically open a command window for the batch file, in case the batch file wants to print output or prompt for input. This also applies if you launch the bat file from a Java process.
Unfortunately, Windows itself apparently provides no way to launch a batch file without such a window. To avoid the window, you will have to run the batch file via some helper program. There are several available; google for "run bat no window" to find some.
If you just want the window to go away after the batch file terminates: That should happen automatically. If it does not, some program launched by the batch file is still running.

start /b [bat file name]