JAVA - reading from text file, recognizing new lines

Question

I have a task to read a text file with several lines, after that I need to count every character's UNICODE value, so the sum of "hello" is 532 and for "how are you" is 1059 and so on, every string begins on new line in the .txt document and so far so good. But for every line I need to print only its own value, and the way my code works, it adds every line's value and I cant get my head around a way to stop it when the end of the lxtine comes so it looks something like: *read line *count char values *add up *print them *start over for the next line, and so

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.lang.String;
import java.util.Arrays;

public class SumLines {

    public static void main(String[] args) {

        String filePath = "/home/lines.txt"; 
        String readLine;
        int sum = 0;

        try (BufferedReader bufferedReader = new BufferedReader(new    FileReader(filePath))) {
            while ((readLine = bufferedReader.readLine()) != null) {
                char[] array = new char[readLine.length()];
                System.out.println(readLine);

                for (int i = 0; i < readLine.length(); i++) {

                    Arrays.fill(array, readLine.trim().charAt(i));
                    sum += (int) array[i];

                    System.out.print(sum + " ");
                }
            }
        } catch (IOException e) {
            System.out.println("Error.\n Invalid or missing file.");
            e.printStackTrace();
        }
       System.out.println("\n*** final " + sum);
    }
}

OP here, in short: How can I tell when the new line begins (if that can help my case) — Ivan Uch
– Ivan Uch, Commented Mar 26, 2016 at 12:34

janos · Accepted Answer · 2016-03-26 12:53:06Z

If I understood correctly, for the input:

hello
how are you

You would like to get something like this as output:

hello 532
how are you 1059

*** final 1591

For this, you need to make some modifications to your code:

In addition to calculating the sum of characters values per line, keep another sum of the total of all lines
For each input line, print the line followed by the sum of character values
You don't need an array at all
It's better to trim the input line once, instead of for every character

Like this:

    int total = 0;

    try (BufferedReader bufferedReader = new BufferedReader(new    FileReader(filePath))) {
        String readLine;
        while ((readLine = bufferedReader.readLine()) != null) {
            String trimmed = readLine.trim();
            int sum = 0;
            for (int i = 0; i < trimmed.length(); i++) {
                sum += (int) trimmed.charAt(i);
            }
            System.out.println(readLine + " " + sum);
            total += sum;
        }
    } catch (IOException e) {
        System.out.println("Error.\n Invalid or missing file.");
        e.printStackTrace();
    }
    System.out.println("\n*** final " + total);

dryairship · Accepted Answer · 2016-03-26 12:34:00Z

0

After your for loop, set sum to 0. If you want to print the total sum, then you need another variable, say t.

Like this:

for (int i = 0; i < readLine.length(); i++) {
    Arrays.fill(array, readLine.trim().charAt(i));
    sum += (int) array[i];
    System.out.print(sum + " ");
}
t=t+sum;
sum=0;

Then print t at the end.

edited Mar 26, 2016 at 12:34

answered Mar 26, 2016 at 12:30

dryairship

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3 Comments

RubioRic Over a year ago

More actions are to be done because total sum is displayed at the end.

dryairship Over a year ago

@RubioRic That was not mentioned in the question, But, if it is necessary, then another varibale can be added. Wait, I am editing it.

RubioRic Over a year ago

It's not explicitly in the question but your original solution would generate another problem for the OP.

randers · Accepted Answer · 2016-03-26 12:34:05Z

A simple solution would be to limit the scope of the sum variable. That way, values will not persist between runs:

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.Reader;
import java.lang.String;
import java.util.Arrays;

public class SumLines {

    public static void main(String[] args) {

        String filePath = "/home/lines.txt"; 
        String readLine;
        int totalSum = 0;

        try (BufferedReader bufferedReader = new BufferedReader(new    FileReader(filePath))) {
            String readLine;
            while ((readLine = bufferedReader.readLine()) != null) {
                int sum = 0;

                for (int i = 0; i < readLine.length(); i++) {
                    sum += (int) readLine.charAt(i);
                }

                System.out.println(readLine + ": " + sum);
                totalSum += sum;
            }
        } catch (IOException e) {
            System.out.println("Error.\n Invalid or missing file.");
            e.printStackTrace();
        }
       System.out.println("\n*** final " + totalSum);
    }
}

Also, you don't have to use such complicated stuff just to get the Unicode value of a char. I made some improvements.

Student · Accepted Answer · 2016-03-26 12:34:38Z

Have two variables, one for final sum and one for line sum.

  public class SumLines {

public static void main(String[] args) {

    String filePath = "/home/lines.txt"; 
    String readLine;
    int totalSum = 0;
    int lineSum = 0

    try (BufferedReader bufferedReader = new BufferedReader(new    FileReader(filePath))) {
        while ((readLine = bufferedReader.readLine()) != null) {
            char[] array = new char[readLine.length()];
            System.out.println(readLine);

            for (int i = 0; i < readLine.length(); i++) {

                Arrays.fill(array, readLine.trim().charAt(i));
                lineSum += (int) array[i];

                System.out.print(lineSum + " ");
            }
            totalSum += lineSum + totalSum;
            lineSum = 0;
        }
    } catch (IOException e) {
        System.out.println("Error.\n Invalid or missing file.");
        e.printStackTrace();
    }
   System.out.println("\n*** final " + totalSum);
}

}

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