Java: Copying an exe-file and launching afterwards fails

Question

Hi,

I want to copy an existing .exe-file from one directory to another and launch it afterwards with Java. Like this:

FileIO.copy( new File( sourceFile ), new File( targetFile ) );
System.out.println( "Existing: " + new File( targetFile ).exists() );
System.out.println( "Launching " + targetFile );
String cmd[] = { targetFile };
Process p = Runtime.getRuntime().exec( cmd );
p.waitFor();
System.out.println( "Result: " + p.exitValue() );

The output is like this:

Existing: true
Launching C:\test\Launcher.new.exe
Result: 2

So Java says that the file is valid and existing, but Windows just can't launch the process because it thinks the file is not there. The pathes are absolute and with backslashes. I also have all permissions on the files so I'm allowed to execute them. The Launcher.new.exe is generated by Launch4j, so it's more or less standalone. At least it doesn't depend on DLLs in the same folder. But strange: It works when I copy and launch the notepad.exe.

One more strange thing: If I don't copy the file by Java but by hand, the launching also fails with the same error.

OS is Vista with SP1.

Any clue?

Answer 1

Hmm... I wonder if this might be Vista's wonderful User Access Controls at play...

Are you working within Program Files? If so, move everything out into a seperate folder (c:\CopyTest) and try again - see if that helps...

Answer 2

If your path contains forward slashes, you might want to try changing them to backslashes before execing. Also, you should try to make the path absolute, including a drive letter and colon (e.g. C:\test\myprog.exe). Note that if you code the path in a Java String, you need to double up the backslashes...

Once you get that working, you can ease up on those constraints until you figure out what broke your attempt.

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EDIT 1: Some common pitfalls with exec() are mentioned in this article. I don't think any of these apply, but you may want to use the coding from the last example to run your .EXE within CMD.EXE to get decent path resolution, error handling and such.

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EDIT 2: Your executable file name needs to be interpreted as a long file name. I'm not positive the API can/will handle this. Please try giving the .EXE a short, simple name (just for testing) like NEWPROG.EXE (with no second dot in the name, either!) But first definitely give it a try with CMD.EXE first.

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EDIT 3: From reading comments to the other answer: Is it possible your program is indeed running, and itself returning a status of 2 because it is failing to find a file? Is there some way to verify operation of your program, perhaps by calling it from a .CMD batch script that you run from your Java program, and having it write output redirected to a file?

Answer 3

Without more details, it's hard to give specific answer. Check your permissions on the c:\test directory and the permissions on target file you are trying to execute.