@Override
        public InputStream openStream() {
            try{
                return new FileInputStream(file);
            }catch (FileNotFoundException ex){
                // NOTE: Can still happen even if file.exists() is true, e.g.
                // permissions issue and similar
                throw new AssetLoadException("Failed to open file: " + file, ex);
            }
        }
<code>FileLocator</code> allows you to specify a folder where to
look for assets. 

@author Kirill Vainer
jme3-core/src/plugins/java/com/jme3/asset/plugins/FileLocator.java