Java BufferedReader read one line

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

public class Main {
  public static void main(String[] args) throws IOException {

    BufferedReader reader = new BufferedReader(new FileReader(new File("files/lines.txt")));
    String lines = reader.readLine();
    while (lines != null) {
      int currentSum = 0;
      for (int i = 0; i < lines.length(); i++) {
        currentSum += lines.charAt(i);//from   w  w  w  . j a  v a  2 s .  com
      }
      lines = reader.readLine();
      System.out.println(currentSum);
    }
    reader.close();
  }
}