* Native extraction will place natives in working directory unless its non-writable, in that case it will place them in <home dir>/.jme3/natives_<apphash>

* Hopefully fixed NPE in computing extraction hash

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@8486 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/desktop/com/jme3/system/Natives.java

@@ -63,11 +63,17 @@ public class Natives {
             return extractionDirOverride;
         }
         if (extractionDir == null) {
+            File workingFolder = new File("").getAbsoluteFile();
+            if (!workingFolder.canWrite()) {
+                logger.log(Level.WARNING, "Working directory is not writable. Using home directory instead.");
                 extractionDir = new File(JmeSystem.getStorageFolder(),
                         "natives_" + Integer.toHexString(computeNativesHash()));
                 if (!extractionDir.exists()) {
                     extractionDir.mkdir();
                 }
+            } else {
+                extractionDir = workingFolder;
+            }
         }
         return extractionDir;
     }
@@ -75,8 +81,8 @@ public class Natives {
     private static int computeNativesHash(){
         try {
             String classpath = System.getProperty("java.class.path");
-            URL url = Natives.class.getResource("");
+            URL url = Thread.currentThread().getContextClassLoader().getResource("com/jme3/system/Natives.class");
-            if (url != null) {
+            
             StringBuilder sb = new StringBuilder(url.toString());
             if (sb.indexOf("jar:") == 0) {
                 sb.delete(0, 4);
@@ -88,7 +94,7 @@ public class Natives {
             } catch (MalformedURLException ex) {
                 throw new UnsupportedOperationException(ex);
             }
-            }
+            
             URLConnection conn = url.openConnection();
             int hash = classpath.hashCode() ^ (int)conn.getLastModified();
             return hash;