Firstly i have googled this question and the only answers i seem to get are using System.exit(0); which isn't what i am looking for. Currently i am opening a program using
Runtime runtime = Runtime.getRuntime();
runtime.exec("C:\\Program Files\\program folder\\program.exe");
This sucessfully opens the program. However closing the program looks like a completely different kettle of fish. Is it possible to close the program through java due to permissions and security? Also can this be done using runtime or is this more complex issue? As i can see that a windows only solution would be to use
taskkill /IM program.exe
However my question would be, if i initiated a taskkill would this shut down the program straight away? or would it tell the program to start to initiate the shutdown process?
Edit:
I Will advise that the program that will be initiated will deal with an access database
You get a Process back when you do the runtime.exec. On that process instance, there is a destroy method:
http://docs.oracle.com/javase/7/docs/api/java/lang/Process.html
Runtime runtime = Runtime.getRuntime();
Process p = runtime.exec("C:\\Program Files\\program folder\\program.exe");
p.destroy()
You can do:
Process p2 = runtime.exec("c:\\windows\\system32\\taskkill /IM program.exe")
it is a standard kill not a forceful one (that requires /F), hence it will simply notify the program it should terminate spontaneously.
I could not try with your program, but I opened notepad typed some text and before saving, I used this way to terminate it and notepad asked me if I wanted to save my work.
With the /F option notepad was terminated immediately leaving the file unsaved.
This is the same difference you have in unix between kill vs and kill -9.
Note that this will terminate all the instances of you process, otherwise you should use the pid.
And if your program upon signaling will be able to comply and try to close the open connections and terminate, it will depend on the program itself.
Related
Im creating a javafx application to run a unix binary application, which limits the percent of cpu a process can use, herein i already have a cputhrottle unix binary which receives PID and CPU percentage as argument, my application just acts as a GUI for this unix binary.
When I run this cputhrottle from terminal it keeps on running, until i press - CTRL+C (this is the normal behavior).
But the problem is, when I run this unix binary with my java code, it seems, as if the program is almost immediately terminated (whereas it should be running, until I press the stop button), and because its not running & being terminated, My program cannot control the percentage of CPU a process gets.
Here's my code : http://pastebin.com/rbG3ctfH
so, is there a way to tell java to keep running the cputhrottle binary file, instead of closing it.
I've tried replacing the 56th line, and instead wrote code to execute a script, which would create a file, with some text content, & when executed he program, it did created a file, so its working, but when i add e1.printStackTrace in the catch block, it stops working for some reason.
And also, if I add sleep in the shell script, then its not executed Properly, more over no Exception is being Generated.
The command you are trying to run ("echo dkkdk|sudo....) is a shell command. You need to tell runtime.exec() to run 'bash -c echo dkkdk|sudo..'
Also be aware that runtime.exec is asynchronous and could/might/likely will return to your program before the child process completes.
Also, I could not pipe the superuser password to sudo like you are trying to do. Not saying it doesn't work for you just that I couldn't get my system to take it.
In a Java program I am running another Java program using the following command:
Process p = Runtime.getRuntime().exec("echo.bat | java -Xms64M -Xmx1G -cp "+execFilePath+" "+inputFileName+" "+inputParam);
The invocation is working fine, but if due to bad coding the executed Java file (inputFileName) is hanging, say, due to some infinite loop, a new process which got started, is not ending. Now, I need to kill that process in my code.
I am able to detect if the Java program is hanging by using TimeOut. But, I don't know how to get the process id of this executed Java program and kill it once TimeOut happens.
Any help is appreciated!
Generally, you can call destroy on your Process instance. See here
I notice however that you are starting one process and pipe its output to another. The simple approach will most probabely only kill the former (your echo.bat process).
Therefore, you need a more complex scenario. Do the following:
Start a process calling echo.bat only
Wait until it is finished
Read all of its output through its output stream (Process.getOutputStream())
Start another process, calling the java program only.
Write the read data to its input (write to Process.getInputStream())
This second process instance will be your java process
As fge mentioned above, take a look at ProcessBuilder, as it simplyfies some of the steps. Especially setting up the input stream can be accomplished before actually starting the program
I am trying to write a chatbot. I am still in my startings, but I do have one question.
Process proc = Runtime.getRuntime().exec("notepad.exe");
This actually makes it impossible to quit my program, unless I quit the notepad. Is it possible to quit the Java program before this notepad has ended?
You can run an external program via a separate thread in your program and continue your program logic in your main thread, i.e. a multi-threaded application is a good solution.
First destroy the subprocess :
Process proc = Runtime.getRuntime().exec("notepad.exe");
proc.destroy();
If this doesn't work, get the process id of the process and run a different subprocess to run kill <pid>
then exit java with System.exit(0); or normally.
I have a java program that is supposed to run a bat file, and then exit with a success code 0.
The code essentially looks like this
Runtime.exec(....);
System.exit(0);
99.8% of the time, this works perfectly. But very sporadically the bat file won't get run.
My theory is that on certain systems, the Runtime.exec can't finish its spawning before the System.exit runs. Is this likely/possible?
I looked at the source of Runtime.exec but it drops into native code to do the interesting stuff.
EDIT
Based on the answers so far, I should state that the .bat file executes another java process using javaw. I can confirm that the 1st java process ending does NOT kill the 2nd one run in the bat file.
Is it possible that when the problem happens the bat file hadn't spawned the 2nd java process before the System.exit occurred? Perhaps it is not a Runtime.exec problem after all?
EDIT2
I cannot wait for the 2nd process to end, it could run indefinitely and my 1st process must exit.
Try to change to ProcessBuilder. Maybe it works better.
You are creating a child process that will terminate with its parent. You must use Process.waitFor in Java to ensure that Java process waits for the bat process to finish.
System.exit(0) kills jvm instance. All process will be terminated. If you want to really execute System.exit(0), make sure exec process is done before calling System.exit.
Use Process.waitFor(), the return type of this method is int which gives you the return code as per your current solution using Runtime.
waitFor() causes the current thread to wait, if necessary, until the process represented by this Process object has terminated.
Change it to
Runtime.getRuntime().exec(....).waitFor();
System.exit(0);
But then this will wait for batch file to complete execution and in your case completion of javaw instance.
Can a Java.exe JVM restart itself somehow? If you have a Java program running in a DOS shell (NOT as a service), what is the cleanest, most efficient way for it to shut down, close the shell, and restart itself with a different Windows process id and re-open in a different shell with a reloaded classpath?
I expect it's not possible but I thought I should ask and learn from other people by asking.
NOTE: If anyone knows how Eclipse IDE is able to restart itself so cleanly, that is the method I am wanting to use.
The Java Service Wrapper can help here. You can run your Java process under it but not necessarily as a service. You can define restart characteristics, such that if it exits, the Java program is restarted (either by System.exit() or calling WrapperManager.restart()).
The cleanest and simplest way to do that would be to run the program from a DOS batch file (or CMD script, if you prefer). Build a loop into your DOS batch file. You put a :label near the beginning and a GOTO label below your Java process and off it goes. If need be, you can break out of the loop using Ctrl-C.
Create a separate executable that takes a process ID and a command as command line argument, waits for the specified process to close and then runs the specified command. Launch that program, then exit the current instance.
You can either embed that program in your primary program and copy it to a temporary directory to execute it, or include it side-by-side with your program.