cours-info/utils/Utils.java

package utils;

import java.util.Arrays;
import java.util.stream.Collectors;
import java.util.Scanner;
import java.util.function.BiFunction;

public class Utils {

  public static String[] CESAR_DATA_CLEAR = new String[] {
    "un beau texte"
  };

  public static int[] CESAR_DATA_KEYS = new int[] {
    7
  };

  public static String[] CESAR_DATA_CRYPT = new String[] {
    "crypt"
  };

  public static final void afficher(Object... args) {
    if (args == null) {
      System.out.println("null");
    } else {
      String str = Arrays.stream(args)
        .map(String::valueOf)
        .collect(Collectors.joining(" "));
      System.out.println(str);
    }
    System.out.print(' ');
  }
  public static final void afficherTabInt(int... args) {
    if (args == null) {
      System.out.println("null");
    } else {
      String str = Arrays.stream(args)
        .boxed()
        .map(i -> i+"")
        .collect(Collectors.joining(" "));
      System.out.println(str);
    }
    System.out.print(' ');
  }

  public static int lireEntier() {
    try (Scanner reader = new Scanner(System.in)) {
      System.out.println("Saisir un entier: ");
      return reader.nextInt();
    }
  }

  public static String lireChaine() {
    try (Scanner reader = new Scanner(System.in)) {
      System.out.println("Saisir une valeur et valider: ");
      return reader.nextLine();
    }
  }

  public static void testCesar(BiFunction<char[], Integer, char[]> func,
    boolean chiffre) {
    for (int i = 0; i<CESAR_DATA_KEYS.length; i++) {
      int cle = CESAR_DATA_KEYS[i];
      if (chiffre) {
        afficher("Clair:   " + CESAR_DATA_CLEAR[i]);
        afficher("Chiffré: " + String.valueOf(func.apply(CESAR_DATA_CLEAR[i]
          .toCharArray(), cle)));
        afficher("Attendu: " + String.valueOf(CESAR_DATA_CRYPT[i]));
      } else {
        afficher("Chiffré: " + CESAR_DATA_CRYPT[i]);
        afficher("Clair:   " + String.valueOf(func.apply(CESAR_DATA_CRYPT[i]
          .toCharArray(), cle)));
        afficher("Attendu: " + String.valueOf(CESAR_DATA_CLEAR[i]));
      }
    }
  }

}