问在Ruby中冻结随机数

EN

class StaticPagesController < ApplicationController
respond_to :html, :js
before_filter :pickanimals

def pickanimals
    @allAnimals = Animal.all
    @random_no = rand(@allAnimals.length)
    @animal = @allAnimals[@random_no]
    @allAnimals.delete_at(@random_no)
    @newRandom = rand(@allAnimals.length)
    @animal2 = @allAnimals[@newRandom]
end

  def index
    respond_to do |format|
        format.html
        format.js
    end
end

  def help
  end

  def about
  end

  def contact
  end

def league
end

def voting
    @votedAnimal = Animal.find(params[:id])
    if @votedAnimal == @animal
        @animal.rating += 1
        @animal2.rating -= 1
    else
        @animal.rating -= 1
        @animal2.rating += 1    
    end
    Animal.transaction do
        @animal.save!
        @animal2.save!
    end
    respond_to do |format|
        format.html { redirect_to root_path }
        format.js  
    end
end
end

<div class="center hero-unit">
<h1>Animal Attack</h1>
<p> Who will win when nature collides? </p>
<div class="animalcontainerright">
<h2> <%= @animal.name %> </h2> 
<%= link_to image_tag(@animal.attachment.url(:large)), voting_path(@animal.id), :remote => true, :confirm => "Rating:  "+@animal.rating.to_s  %>
</div>
<div class="animalcontainerleft">
<h2> <%= @animal2.name %> </h2>
<%= link_to image_tag(@animal2.attachment.url(:large)), voting_path(@animal2.id), :remote => true, :confirm => "Rating:  "+@animal2.rating.to_s  %>
</div>
<div id="animalfacts"></div>

AnimalAttack::Application.routes.draw do

resources :animals

root to: 'static_pages#index'
match '/help' => 'static_pages#help'
match '/about' => 'static_pages#about'
match '/contact' => 'static_pages#contact'
match '/league' => 'static_pages#league'
match '/voting/:id' => 'static_pages#voting'

end

    animals GET    /animals(.:format)          animals#index
        POST   /animals(.:format)          animals#create
 new_animal GET    /animals/new(.:format)      animals#new
edit_animal GET    /animals/:id/edit(.:format) animals#edit
 animal GET    /animals/:id(.:format)      animals#show
        PUT    /animals/:id(.:format)      animals#update
        DELETE /animals/:id(.:format)      animals#destroy
   root        /                           static_pages#index
   help        /help(.:format)             static_pages#help
  about        /about(.:format)            static_pages#about
contact        /contact(.:format)          static_pages#contact
 league        /league(.:format)           static_pages#league
               /animals(.:format)          animals#new
               /voting/:id(.:format)       static_pages#voting