utils

package entregable.util;

import java.util.Scanner;
import java.io.*;

public class Util {

    private static final String abc = "abcdefghijklmnopqrstuvwxyz";

    public static String cfr(String inp, int n) {
        char cif, sinCif;
        int posiAbc, posiCif;
        String out = "", aux;
        boolean may;

        for (int i = 0; i < inp.length(); i++) {
            may = false;
            sinCif = inp.charAt(i);
            if (Character.isUpperCase(sinCif)) {
                sinCif = Character.toLowerCase(sinCif);
                may = true;
            }
            posiAbc = abc.indexOf(sinCif);
            if (posiAbc == -1) {
                cif = sinCif;
            } else {
                posiCif = posiAbc + n;
                if (posiCif > 25) {
                    posiCif = posiCif % 26;
                } else if (posiCif < 0) {
                    posiCif = posiCif + 26;
                }
                cif = abc.charAt(posiCif);
            }
            if (may == true) {
                aux = String.valueOf(cif).toUpperCase();
            } else {
                aux = String.valueOf(cif);
            }
            out = out + aux;
        }

        return out;
    }

    public static int sacarDesplazamiento(String nom) {
        File fi;
        Scanner scFile;
        int n, max = -1, posi = 0;
        int[] ia = new int[26];
        String linea;
        char l;

        fi = new File(nom);
        try {
            scFile = new Scanner(fi);
            while (scFile.hasNextLine()) {
                linea = scFile.nextLine().toLowerCase();
                for (int i = 0; i < linea.length(); i++) {
                    l = linea.charAt(i);
                    n = abc.indexOf(l);
                    if (n != -1) {
                        ia[n]++;
                    }

                }

            }

            for (int i = 0; i < ia.length; i++) {
                if (ia[i] > max) {
                    max = ia[i];
                    posi = i;
                }
            }

        } catch (FileNotFoundException ex) {
            System.out.println("No existe el fichero.");
        }

        return 4 - posi;
    }

    public static void common(String nom, int desp, File fo) throws Exception {
        if (desp > 25 || desp < -25) {
            throw new Exception();
        }
        File fi;
        FileWriter fw = null;
        Scanner scFile = null;
        String linea;

        fi = new File(nom);
        if (!fi.exists()) {
            System.out.println("El fichero no existe.");
        } else {

            try {
                scFile = new Scanner(fi, "UTF-8");
                fw = new FileWriter(fo);

                while (scFile.hasNextLine()) {
                    linea = scFile.nextLine();
                    linea = cfr(linea, desp);
                    fw.write(linea + "\n");
                }

            } catch (FileNotFoundException ex) {
                System.out.println("Archivo no encontrado.");
            } catch (IOException ex) {
                System.out.println("Error en el fichero de escritura.");
            } finally {
                if (scFile != null) {
                    scFile.close();
                }
                if (fw != null) {
                    try {
                        fw.close();
                    } catch (IOException e) {
                        System.out.println("Error al cerrar el fichero de escritura.");
                    }
                }
            }

        }

    }

}