public VolatileContentImpl(String contentType, byte[] bytes) {
   super();
   this.id = ID.generateLong();
   this.contentType = contentType;
   this.bytes = bytes;
   synchronized (volatileMap) {
     volatileMap.put(new Long(this.id), this);
   }
 }
 public static VolatileContentImpl getVolatileContent(long id) {
   synchronized (volatileMap) {
     return (VolatileContentImpl) volatileMap.get(new Long(id));
   }
 }