Random Generator : Random « Development « Android

1. Android
2. Development
3. Random

Random Generator

    
//package br.com.tecnove.random.android.util;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Random;

public class RandomGenerator {

  private static final Random r = new Random();

  /**
   * Random a value from a specified range
   * 
   * @param min
   *            minimun range (inclusive)
   * @param max
   *            maximun range (inclusive)
   * @return randomed int value
   */
  public static int generateFromRange(int min, int max) {
    // swap values if they come in the wrong order
    if (min > max) {
      int aux = min;
      min = max;
      max = aux;
    }
    int i = max - min;
    int x = r.nextInt(i + 1);
    return x + min;
  }

  /**
   * Random a value from a string vector
   * 
   * @param input
   *            String[] containing all the possible values
   * @return randomed String value
   */
  public static String generateFromStringArray(String[] input) {
    int i = generateFromRange(0, input.length - 1);
    return input[i];
  }

  /**
   * Random a value from a string collection. Just a facilitator for the generateFromStringArray
   * 
   * @param input
   *            Collection of String that contains the possible values
   * @return randomed String value
   */
  public static String generateFromStringCollection(Collection<String> input) {
    return generateFromStringArray((String[]) input.toArray());
  }

  /**
   * Generate a random upercase char
   * 
   * @return randomed char
   */
  public static char generateLetter() {
    return (char) generateFromRange((int) 'A', (int) 'Z');
  }
  
  /**
   * Generate random numbers for a lottery
   * @param maxRange limit the range from 1 to this number (included) 
   * @param numbersToGenerate how many numbers will be generated 
   * @return List of Integers with the non repeating values 
   */
  public static List<Integer> generateLottery(Integer maxRange, Integer numbersToGenerate) {
    List<Integer> numbersGenerated = new ArrayList<Integer>();
    for (int c = 0; c < numbersToGenerate; c++) {
      int nGenerated = 0;
      do {
        nGenerated = r.nextInt(maxRange);
        // adding +1 to make the int start at 1 and the maxRange be included in the sorted values
        nGenerated++;
        // if the number is allready on the list, sort a new number
      } while (numbersGenerated.contains(nGenerated));
      numbersGenerated.add(nGenerated);
    }
    return numbersGenerated;
  }
  
  /**
   * Random a value from a string with values separated by '/'
   * @param valor
   * @return
   */
  public static String generateFromString(String valor) {
    // the input must be like: curitiba/fortaleza/google/facebook/android/motorola
    String[] vetor = valor.split("/");
    String outValue = "";
    if (vetor.length>0){
      outValue = vetor[r.nextInt(vetor.length)];
    }
    return outValue;
  }
}

   
    
    
    
  

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