When reading a file in java, the program compiles, but there is no result, what should I do?

Question

Java

When reading a file in java, the program compiles, but there is no result, what should I do?

class files{
    public static void main(String args[]){
        try{ 
            BufferedReader kf = new BufferedReader(new FileReader("C:/Users/Shhhn/IdeaProjects/untitled/src/koeff.txt"));

            String line = kf.readLine();

            //коэфициенты квадратного уравнения
            int a1 = 0;
            int b1 = 0;
            int c1 = 0;

            while (line != null){
                for (int i = 0; i != line.length(); ++i){ 
                    char kof0 = line.charAt(i); 
                    String kof1 = String.valueOf(kof0);
                    //начало главного while
                    while(kof1!=" "){
                        String a = kof1;
                        a1 = Integer.parseInt(a);
                        int index_len_a = a.length()+1;
                        if(i==index_len_a){
                            while(kof1!=" "){
                                String b = kof1;
                                b1 = Integer.parseInt(b);
                                int index_len_b = b.length()+1;
                                if(i==index_len_b){
                                    while(kof1!=" "){
                                        String c = kof1;
                                        c1 = Integer.parseInt(c);
                                    }
                                }
                            }
                        }
                    }
                    //конец главного while

                    double discrim = Math.sqrt(b1*b1-4*a1*c1);

                    if(discrim<0){
                        System.out.println("solve not");
                    }
                    else{
                        double x1 = 0;
                        double x2 = 0;

                        x1 = (-1*b1+discrim)/(2*a1);
                        x2 = (-1*b1-discrim)/(2*a1);

                        System.out.println("x1 = "+x1+" x2 = "+x2);
                    }

                }
            }
            kf.close();
        }catch (IOException e){
            System.out.println("Файл не найден!");
        }
    }
}

Answer 1

That's why, why, in any programming courses, no matter Java or any other language, they don't teach how to use a debugger, or at least place prints in all places?!
Gentlemen and ladies, teachers, teachers, coaches, coaches - well, first of all, teach, using the example of Hell Programming World, how to debug your creations in all possible ways.
Java is a separate conversation, in it the debugger in each IDE sticks out like a mute reproach, and the button is nearby - just stick a breakpoint.

Answer 2

What to do? .. as the great Krupsky said, "study, study and study again"
For your code is not a solution to a quadratic equation, it is some kind of hellish Soton.
Everything is terrible in it - from the name of the class to five (FIVE, CARL !!!) nested loops.

• make a function that parses a string and returns parameters
  
• make a function that solves a quadratic equation with the given parameters
  
• make one loop that reads the file line by line, calls a function that parses the line and returns the parameters, and then calls the function that solves the quadratic equation with the given parameters
  

and don't forget the debugger