void saveOffsetInExternalStore(String topic,int partition,long offset){
  try {
    FileWriter writer=new FileWriter(storageName(topic,partition),false);
    BufferedWriter bufferedWriter=new BufferedWriter(writer);
    bufferedWriter.write(offset + "");
    bufferedWriter.flush();
    bufferedWriter.close();
  }
 catch (  Exception e) {
    e.printStackTrace();
    throw new RuntimeException(e);
  }
}

void saveOffsetInExternalStore ( String topic , int partition , long offset ) { try { FileWriter writer = new FileWriter ( storageName ( topic , partition ) , false ) ; BufferedWriter bufferedWriter = new BufferedWriter ( writer ) ; bufferedWriter . write ( offset + "" ) ; bufferedWriter . flush ( ) ; bufferedWriter . close ( ) ; } catch ( Exception e ) { e . printStackTrace ( ) ; throw new RuntimeException ( e ) ; } }
overwrite the offset for the topic in an external storage .
