forceDelete

      /**
* try to delete given file , try 10 times
* @param f
* @return true if file deleted success, nor false;
*/ 
public static boolean forceDelete(File f) 
{ 
    boolean result = false; 
     int tryCount = 0; 
     while(!result && tryCount++ <10){ 
    System.gc(); 
    result = f.delete(); 
} 
return result; 
}