- change natives extraction to check for space *and* writability

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@8515 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

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

@@ -58,13 +58,13 @@ public class Natives {
         extractionDirOverride = new File(name).getAbsoluteFile();
     }
 
-    public static File getExtractionDir(){
+    public static File getExtractionDir() {
         if (extractionDirOverride != null) {
             return extractionDirOverride;
         }
         if (extractionDir == null) {
             File workingFolder = new File("").getAbsoluteFile();
-            if (workingFolder.getUsableSpace()>0) {
+            if (workingFolder.getUsableSpace() == 0 || !workingFolder.canWrite()) {
                 logger.log(Level.WARNING, "Working directory is not writable. Using home directory instead.");
                 extractionDir = new File(JmeSystem.getStorageFolder(),
                         "natives_" + Integer.toHexString(computeNativesHash()));
@@ -78,7 +78,7 @@ public class Natives {
         return extractionDir;
     }
 
-    private static int computeNativesHash(){
+    private static int computeNativesHash() {
         try {
             String classpath = System.getProperty("java.class.path");
             URL url = Thread.currentThread().getContextClassLoader().getResource("com/jme3/system/Natives.class");
@@ -96,7 +96,7 @@ public class Natives {
             }
 
             URLConnection conn = url.openConnection();
-            int hash = classpath.hashCode() ^ (int)conn.getLastModified();
+            int hash = classpath.hashCode() ^ (int) conn.getLastModified();
             return hash;
         } catch (IOException ex) {
             throw new UnsupportedOperationException(ex);
@@ -130,14 +130,14 @@ public class Natives {
         File targetFile = new File(getExtractionDir(), fullname);
 
         try {
-            if (targetFile.exists()){
+            if (targetFile.exists()) {
                 // OK, compare last modified date of this file to 
                 // file in jar
                 long targetLastModified = targetFile.lastModified();
                 long sourceLastModified = conn.getLastModified();
 
                 // Allow ~1 second range for OSes that only support low precision
-                if (targetLastModified + 1000 > sourceLastModified){
+                if (targetLastModified + 1000 > sourceLastModified) {
                     logger.log(Level.FINE, "Not copying library {0}. Latest already extracted.", fullname);
                     return;
                 }
@@ -169,7 +169,7 @@ public class Natives {
         logger.log(Level.FINE, "Copied {0} to {1}", new Object[]{fullname, targetFile});
     }
 
-    protected static boolean isUsingNativeBullet(){
+    protected static boolean isUsingNativeBullet() {
         try {
             Class clazz = Class.forName("com.jme3.bullet.util.NativeMeshUtil");
             return clazz != null;