Egzamin PP&JP: ????, Zad.? ?

package javaapplication16;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;
import java.io.RandomAccessFile;

public class JavaApplication16
{

    public static void main(String[] args)
    {


    }

    void Nadwaga(String nazwa)
    {
        String linia = "";
        String imie;
        double waga;
        double wzrost;
        double BMI;
        try(BufferedReader br = new BufferedReader( new FileReader(nazwa) );
                RandomAccessFile raf1 = new RandomAccessFile("nadwaga.bin", "rw");
                RandomAccessFile raf2 = new RandomAccessFile("niedowaga.bin", "rw");
                )
        {
            do
            {
              linia = br.readLine();
              imie = linia.split("-")[0];
              waga = Double.parseDouble(linia.split("-")[2]);
              wzrost = Double.parseDouble(linia.split("-")[3]);
              BMI = (waga/(wzrost*wzrost));

              if(BMI < 18.5)
              {
                  raf2.writeUTF(imie);
                  raf2.writeDouble(BMI);
              }
              else if (BMI >= 25.0)
              {
                  raf1.writeUTF(imie);
                  raf1.writeDouble(BMI);
              }


            } while(linia != null);
        }

        catch(IOException e)
        {
            System.out.println(e.getMessage());
        }
    }
}