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?
public ProcessBuilder(String... command) Constructs a process builder with the specified operating system program and arguments. This is a convenience constructor that sets the process builder's command to a string list containing the same strings as the command array, in the same order.
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
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.
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