Java NumberFormatException Skip Line

Question

I'm writing a program that reads in a list of numbers. Such as:

45
63
74g
34.7
75

I simply want my program to skip lines that contain any letters in them. Any help would be greatly appreciated. Thanks!

If it makes a difference, here is my code:

import java.io.*;

public class ScoreReader {

    public static void main(String[] args) {
        BufferedReader reader = null;

        try {
            String currentLine;

            reader = new BufferedReader(new FileReader("QuizScores.txt"));
            while ((currentLine = reader.readLine()) != null) {

                int sum = 0;

                String[] nums = currentLine.split("\\s+");
                for (int i = 0; i < nums.length; i++) {
                    int num = Integer.parseInt(nums[i]);
                    if (num != -1) {
                        sum += num;
                    }
                }

                System.out.println(sum / nums.length);
            }
        } catch (IOException err) {
            err.printStackTrace();
        } 
        catch (NumberFormatException err) {

        }

        finally {
            try {
                if (reader != null)
                    reader.close();
            } catch (IOException err) {
                err.printStackTrace();
            }
        }

    }
}

Answer 1

When an exception is thrown, execution jumps to the catch block. In what you have, this is after the loop, so the loop doesn't continue, just add a try around parseInt.

try {
   String currentLine;

   reader = new BufferedReader(new FileReader("QuizScores.txt"));
   while ((currentLine = reader.readLine()) != null) {

       int sum = 0;
       String[] nums = currentLine.split("\\s+");
       for (int i = 0; i < nums.length; i++) {
           try{
               int num = Integer.parseInt(nums[i]);
               if (num != -1) {
                   sum += num;
               }
           } catch( NumberFormatException nfe )
           {
              // maybe log it?
           }
       }

       System.out.println(sum / nums.length);
   }
} catch (IOException err) {
    err.printStackTrace();
} 
// catch (NumberFormatException err) {}
finally {
    try {
       if (reader != null){
           reader.close();
    } catch (IOException err) {
        err.printStackTrace();
    }
}

Also note, you are using Integer.parseInt which will throw an exception with the input "34.7", so maybe you wish to use Double.parseDouble