Entering data from a Java text document, can it be simplified somehow?

Question

Java

Beginner Java programmer. Faced a situation when it is necessary to take the data from a text file. In this case, the file contains an integer 10. When I tried to read from the file, I got 48 and 47. Why this happens, I still have not figured out. I noticed that if these numbers are converted to char, then it displays what I need. As a result, to get the integer 10 that was in the file, I had to convert the value several times:

import java.io.*;

public class Test {

  public static void main(String[] args) throws IOException{
    FileInputStream reader = new FileInputStream("D:\\Eclipse\\workspace\\MyExperimentalProject\\files\\input.txt");
    int a = 0;
    String result = "";
    
    while (true) {
      a = reader.read();
      if (a == -1) {
        break;
      }
      result = result + (char)a;
    }
    System.out.println(result); //для сравнения результата
    Integer intresult = new Integer(result);
    intresult++;//убеждаюсь в том, что это всё-таки число
    System.out.println(intresult);
}
}

I achieved what I wanted, but it seems to me that I chose the most difficult of all paths. Experienced programmers, please tell me if it is possible to make this process simpler, and if so, how?

Answer 1

You have in the file not the number 10, but the string "10". Here is a conversion example: https://stackoverflow.com/questions/5585779/how-to...
How to parse a string into tokens is a separate task. You can manually, you can use regular expressions.
Look at the table of ASCII codes, find the codes for the characters 1 and 0 there and it will become clear.

Answer 2

I'll give you a little hint:
1) Be sure to be sure which encoding is in the file and which one you are reading.
2) The string is easy to split, for example, so to start with String[] arr = "unknown string with the number 100 and 72".split(" ");
3) Then you can go on the forehead, but this is not entirely good, like this Integer.parseInt( String str ), other primitive types have the same methods.