chunkreader can be openend with empty root folder - asp3engine not!

Author: thsc

src/net/sharksystem/asp3/ASP3EngineFS.java

@@ -24,20 +24,32 @@ private ASP3EngineFS(String rootDirectory,
     public static ASP3ChunkStorage getASP3ChunkStorage(String owner, String rootDirectory) 
             throws IOException, ASP3Exception {
 
+        // check if root directory already exists. If not srt it up
+        File root = new File(rootDirectory);
+        if(!root.exists()) {
+            root.mkdirs();
+        }
+        
         return ASP3EngineFS.getASP3Engine(owner, rootDirectory, null);
 
     }
 
     public static ASP3ChunkStorage getASP3ChunkStorage(String rootDirectory) 
             throws IOException, ASP3Exception {
 
-        return ASP3EngineFS.getASP3Engine(ASP3EngineFS.DEFAULT_OWNER, rootDirectory, null);
+        return ASP3EngineFS.getASP3ChunkStorage(ASP3EngineFS.DEFAULT_OWNER, rootDirectory);
 
     }
 
     public static ASP3Engine getASP3Engine(String owner, String rootDirectory, 
             ASP3Reader reader) throws IOException, ASP3Exception {
 
+        // root directory must exist when setting up an engine
+        File root = new File(rootDirectory);
+        if(!root.exists() || !root.isDirectory()) {
+            throw new ASP3Exception("chunk root directory must exist when creating an ASP3Engine");
+        }
+        
         ASP3EngineFS engine = new ASP3EngineFS(
                 rootDirectory, 
                 new ASP3StorageFS(rootDirectory),