static void removeSoIfExit(String libName,int version){
  String file=_targetSoFile(libName,version);
  File a=new File(file);
  if (a.exists()) {
    a.delete();
  }
}

static void removeSoIfExit ( String libName , int version ) { String file = _targetSoFile ( libName , version ) ; File a = new File ( file ) ; if ( a . exists ( ) ) { a . delete ( ) ; } }
remove the so library if it had been extracted .
