Question

My app allows to upload csv file with some data.
I want to extract those data and upload them into datastore, but let’s assume for this question, that I just want to count lines in text file.
What is the best approach to make that task done. Could you give me some code sniplet?

public int countLines(BlobKey key){
  //mising code
}

Answer 1

The BlobstoreInputStream extends InputStream so you can do something like this —

public int countLines(BlobKey key) throws Exception {
          BlobstoreInputStream bsis = new BlobstoreInputStream(key);
          BufferedReader br = new BufferedReader(new InputStreamReader(bsis));

          int lineCount = 0;
          while ( br.readLine() != null ) 
                 lineCount++;

          return lineCount;
}