[solved] Weird error when launching .jar vs .class

[Jean-Yves Tinevez]

Hi all.

I am still trying to access a directory out of a jar.
I found a way around, this to use :

   
        URL urlToExecutable = [B]getClass().getResource("");[/B]
        File executableDir = new File(urlToExecutable.getPath());
        String pathToParameters = 
                executableDir.getParentFile().getParent()
                + File.separatorChar 
                + "Parameters" 
                + File.separatorChar;
        parametersDir = new File(pathToParameters);
        System.out.println(parametersDir.toString()); 

What's funny and depressing at the same time, is that it does not behave the same at all when I launch the app through the IDE (which launches the .class) and the jar.

The last line of the code i have given should print the path to the executable.
- When i launch it with the IDE (.class), i get this:

  /Users/tinevez/Documents/Development/Java/HBM/build/Parameters  

which is fine and working

- When i launch the .jar i have got something different:

 file:/Users/tinevez/Documents/Development/Java/HBM/dist/Parameters/ 

Appart from the change of directory (which is fine), there is an extra "file:" string that appeared out of nowhere and causes following code to crash.

Why does the .jar and .class behave differently for this issue? And how to find a workaround?

Thanks a lot
jy
[ August 25, 2007: Message edited by: Jean-Yves Tinevez ]

[Yuriy Zilbergleyt]

Not sure about the "why", but isn't the workaround as simple as checking if the path starts with "file:" and removing the unneeded 5 characters if necessary.

[marc weber]

I think this might be a bit advanced for the beginners forum, so I'm promoting this topic to the intermediate forum.

[Jean-Yves Tinevez]

Hi all.

I think i have found the why:

(WARNING: evcerything done on MacOSX10.4)

When you do this:

        URL urlToExecutable = getClass().getResource("/HBM");
        File executableDir = new File(urlToExecutable.getPath());

the executableDir will be differently formed if called from a .class or from a .jar. You can see it with the toString() method. Suppose you convert this to a string.

- When called from a .class, it will be formed like this:

 file:/User/etc/... 

which can be correctly accessed

- When called from a .jar, it is like that:

jar:file:/User/etc/...    

Now if you convert it back to a file, it won't be processed correctly: the 'jar:' prefix will be removed, but not the 'file:' one (apparently it can remove only one prefix).
Which explains the weird log posted up there.

The solution for me was simply to add a line of code manipulating the String to remove the 1st characters up to the 1st ':'

But that's still strange no? What do you think of it?