Can't launch .exe from Java

Question

I am trying to launch a .exe file through a Java program. I used the following code:

System.out.println("Opening " + path);
Process exec;
exec = Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL " + path);//path is the path of the exe file which is passed as an argument from another java class

the output is as follows:

Opening C:\Program Files (x86)\C-Free 5\CppIDE.exe

But it is not opening.

Instead when I try

String pat="C:\\Program Files (x86)\\C-Free 5\\CppIDE.exe";
Process exec;
exec = Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL " + pat);

the program is opened.

I don't know what the problem is.

You may need to wrap the "pat" in quotes "\"c:/Program Files/...\"" — MadProgrammer, Nov 16 '12 at 08:26
Sidenote: why do you use `rundll32` at all? The command you are calling is an `.exe` file, that you should be able to execute directly. — Joachim Sauer, Nov 16 '12 at 08:43
Also visit the JavaWorld article linked from the [exec tag Wiki](http://stackoverflow.com/tags/runtime.exec/info) & implement all the recommendations. I would be more surprised if that code worked, than if it failed. — Andrew Thompson, Nov 16 '12 at 08:43

Joachim Sauer · Answer 1 · 2012-11-16T08:57:24.603

3

It's very likely that the space in your path is the problem.

I suggest you pass the arguments as an array instead of passing a single string containing the whole command (alternatively you could quote the spaces correctly, but that's not quite as easy).

Either

use the String[] version of Runtime.exec() or
switch to using ProcessBuilder which has an altogether simpler and more intuitive API.

With ProcessBuilder this could look like this:

ProcessBuilder pb = new ProcessBuilder("rundll32", "SHELL32.DLL,ShellExec_RunDLL", path);
Process p = pb.start();

Also, I see no reason to invoke rundll32 at all in this scenario. This should work just as well:

ProcessBuilder pb = new ProcessBuilder(path);
Process p = pb.start();

edited Nov 16 '12 at 08:57

answered Nov 16 '12 at 08:31

Joachim Sauer

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The program uses Sockets. The file path in a MySQL database at the Server side. It is read and send to the client via a ServerSocket. I tried printing both 'path'(file path received from Server) and 'pat'(file path given in the program) and both are same. However when i use `Process exec;` `exec = Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL " + path);` The program (CppIDE) is not opening. – salabh Nov 17 '12 at 02:53

score 0 · Answer 2 · answered Nov 16 '12 at 08:31

0

You need to construct the path using File.separator. The path separator you are using will, in this case, will be system dependant.

answered Nov 16 '12 at 08:31

NiranjanBhat

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Doesn't really matter, since `rundll32` is already *pretty* system dependent and every system that has that executable will use \ as the file separator. – Joachim Sauer Nov 16 '12 at 08:33

Can't launch .exe from Java

2 Answers2