Re: get path of a Jar file

Philipp Kraus <>
Sun, 30 Oct 2011 18:49:56 +0100
On 2011-10-24 22:07:18 +0200, Steven Simpson said:

On 22/10/11 10:54, Philipp Kraus wrote:

String l_jarfile =
l_jarfile = l_jarfile.substring(9,
l_jarfile.lastIndexOf(".jar!")) + ".jar";

This does not work on MS Windows systems (unix and OSX work correct
with this code).
If the Jar files is stored under a path like "C:\Users\myuser\Java
Files\myjar.jar" (with a space)
the JarFile-Object can't locate the file, because the space within the
directory is changed to %20

Leaving aside the good questions of why, and whether these magic
constants are a good thing, I will address the decoding of % sequences:
Create a from the string, then create a from
the URI.


public class GetPath {
     public static void main(String[] args) throws Exception {
         Class<?> clazz = Class.forName(args[0]);
         URL clazzRes = clazz.getResource("");
         String loc = clazzRes.toString();
         System.out.println("Resource: " + loc);
         URI stripped =
             URI.create(loc.substring(4, loc.lastIndexOf(".jar!") + 4));
         System.out.println("Stripped: " + stripped);
         File result = new File(stripped);
         System.out.println("Result: " + result);

Lots of result checking omitted.

Thanks, the URI option is imho the best solution


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