I am writing a program in java which would execute winrar and unzip a jar file for me placed in h:\myjar.jar into the folder h:\new. My java code goes something like this
import java.io.File;
import java.io.IOException;
public class MainClass {
public static void main(String[] args) {
Runtime r = Runtime.getRuntime();
Process p = null;
try {
File dir = new File("C:/Program Files/WinRAR");
p = r.exec("winrar x h:\\myjar.jar *.* h:\\new", null, dir);
} catch (IOException e) {
e.printStackTrace();
}
}
}
When I execute this, I am getting this error
java.io.IOException: Cannot run program "winrar" (in directory "C:\Program Files\WinRAR"): CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessBuilder.start(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at java.lang.Runtime.exec(Unknown Source)
at MainClass.main(MainClass.java:16)
Caused by: java.io.IOException: CreateProcess error=2, The system cannot find the file specified
at java.lang.ProcessImpl.create(Native Method)
at java.lang.ProcessImpl.<init>(Unknown Source)
at java.lang.ProcessImpl.start(Unknown Source)
... 4 more
Can anyone tell me why am I encountering such a problem. What is the change I need to incorporate in code so that it works?
Assuming that winrar.exe is in the PATH, then Runtime.exec is capable of finding it, if it is not, you will need to supply the fully qualified path to it, for example, assuming winrar.exe is installed in C:/Program Files/WinRAR you would need to use something like...
p=r.exec("C:/Program Files/WinRAR/winrar x h:\\myjar.jar *.* h:\\new");
Personally, I would recommend that you use ProcessBuilder as it has some additional configuration abilities amongst other things. Where possible, you should also separate your command and parameters into separate String elements, it deals with things like spaces much better then a single String variable, for example...
ProcessBuilder pb = new ProcessBuilder(
"C:/Program Files/WinRAR/winrar",
"x",
"myjar.jar",
"*.*",
"new");
pb.directory(new File("H:/"));
pb. redirectErrorStream(true);
Process p = pb.start();
Don't forget to read the contents of the InputStream from the process, as failing to do so may stall the process
The complete first argument of exec is being interpreted as the executable. Use
p = rt.exec(new String[] {"winrar.exe", "x", "h:\\myjar.jar", "*.*", "h:\\new" }
null,
dir);
The dir you specified is a working directory of running process - it doesn't help to find executable. Use cmd /c winrar ... to run process looking for executable in PATH or try to use absolute path to winrar.
My recomendation is to keep the getRuntime().exec because exec uses the ProcessBuilder.
Try
p=r.exec(new String[] {"winrar", "x", "h:\\myjar.jar", "*.*", "h:\\new"}, null, dir);
I used ProcessBuilder but had the same issue. The issue was with using command as one String line (like I would type it in cmd) instead of String array. In example from above. If I ran
ProcessBuilder pb = new ProcessBuilder("C:/Program Files/WinRAR/winrar x myjar.jar *.* new");
pb.directory(new File("H:/"));
pb. redirectErrorStream(true);
Process p = pb.start();
I got an error. But if I ran
ProcessBuilder pb = new ProcessBuilder("C:/Program Files/WinRAR/winrar", "x", "myjar.jar", "*.*", "new");
pb.directory(new File("H:/"));
pb. redirectErrorStream(true);
Process p = pb.start();
everything was OK.
Source: Stackoverflow.com