How do I read an integer variable from a text document in Java?

Question

I am trying to make a scoring system for a game I'm writing, but I need to be able to read an integer variable from a text document. I can easily get a String variable, but it won't come in as an integer. How would I go about doing that? Here is the code I have for reading and writing the score, but the input won't come in as an integer, as you can see when the println outputs the value of score2 integer. Thanks! I'm using an eclipse IDE for Java by the way.

import java.io.*;

public class ClassName {

    public static void main(String[] args) {

    FileOutputStream output;
    FileInputStream input;
    in score = 10;
    int integer = 4;
        try {
            output = new FileOutputStream("score.txt");
            new PrintStream(output).println(score);
            output.close();
        } catch (IOException e) {}

        try {
            input = new FileInputStream ("score.txt");
            int score2 = (new DataInputStream(score).readLine());
            input.close();
            System.out.println(score2);
        } catch (IOException e) {}
        }

    }
}

Definite duplicate of How to read integer values from text file — Max
– Max, Commented Aug 28, 2014 at 21:02
I did search it, but I didn't see that question. I must not have gone through enough search results or just missed it. Sorry about that. — public static void
– public static void, Commented Aug 28, 2014 at 21:06
@meanIOstack, you're flagging as a dup of a dup. Why not mark the actual dup? — ChiefTwoPencils
– ChiefTwoPencils, Commented Aug 28, 2014 at 21:17

Elliott Frisch · Accepted Answer · 2014-08-28 20:53:25Z

0

I would use a Scanner and try-with-resources,

try (Scanner sc = new Scanner(new File("score.txt"))) {
  int score2 = sc.nextInt();
  System.out.println(score2);
} catch (IOException e) {
  e.printStackTrace();
}

answered Aug 28, 2014 at 20:53

Elliott Frisch

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2 Comments

Max Over a year ago

You are spoon feeding the child. Give a man a fish and he'll eat for a day.

public static void Over a year ago

@MeanlOstack I searched the web as well as the stack overflow questions and didn't find what I was looking for. Elliott's advice was very helpful. I am a beginner programmer and need a lot of code to get what the answer is most of the time.

talex · Accepted Answer · 2014-08-28 20:52:40Z

0

To convert string to int you can use Integer.parse method

answered Aug 28, 2014 at 20:52

talex

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Cyril Duchon-Doris · Accepted Answer · 2014-08-28 20:55:30Z

0

What you want to do is called parsing.

You want to use the parseInt() method of the Integer java class (link to doc)

try{
    Integer.parseInt(new DataInputStream(score).readLine())
} catch (NumberFormatException e) {

}

answered Aug 28, 2014 at 20:55

Cyril Duchon-Doris

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