Modify java.library.path programmatically

[ra4king]

According to this (closed) bug report, java.library.path is meant to be a read-only property. However this workaround solves that problem:

1   2   3   4   5   6   7   8   9   10   11   12   13   14   15   16   17   18   19   20   21   22   23   24

public static void addDir(String s) throws IOException {     try {         // This enables the java.library.path to be modified at runtime        // From a Sun engineer at http://forums.sun.com/thread.jspa?threadID=707176        //        Field field = ClassLoader.class.getDeclaredField("usr_paths");         field.setAccessible(true);         String[] paths = (String[])field.get(null);         for (int i = 0; i < paths.length; i++) {             if (s.equals(paths[i])) {                 return;             }         }         String[] tmp = new String[paths.length+1];         System.arraycopy(paths,0,tmp,0,paths.length);         tmp[paths.length] = s;         field.set(null,tmp);         System.setProperty("java.library.path", System.getProperty("java.library.path") + File.pathSeparator + s);     } catch (IllegalAccessException e) {         throw new IOException("Failed to get permissions to set library path");     } catch (NoSuchFieldException e) {         throw new IOException("Failed to get field handle to set library path");     } }

For those of you who really need to run a LWJGL application by double clicking the jar yet you want the natives in their own subfolder, this is for you

Obviously this might not be portable across JVMs.

Source: http://nicklothian.com/blog/2008/11/19/modify-javalibrarypath-at-runtime/

[Nate]

You can also write a classloader to find the natives and load your app using the classloader.