kaminariによるページネーション

Question

現在、rubyを用いた本棚アプリの書籍画面にrukaminariを用いてページネーションを実装しようとしているのですが、以下のようなエラーコードが吐き出され、成功しません。

なお、
app/controllers/book_controller.rbのようになっております。

class BooksController < ApplicationController
before_action :set_book, only: [:show, :edit, :update, :destroy]

def index
@books = Book.page(params[:page]).per(10)
end

GET /books

GET /books.json

def index
@books = Book.all
end

GET /books/1

GET /books/1.json

def show
end

GET /books/new

def new
@book = Book.new
end

GET /books/1/edit

def edit
end

POST /books

POST /books.json

def create
@book = Book.new(book_params)

respond_to do |format|
  if @book.save
    format.html { redirect_to @book, notice: 'Book was successfully created.' }
    format.json { render :show, status: :created, location: @book }
  else
    format.html { render :new }
    format.json { render json: @book.errors, status: :unprocessable_entity }
  end
end

end

PATCH/PUT /books/1

PATCH/PUT /books/1.json

def update
respond_to do |format|
if @book.update(book_params)
format.html { redirect_to @book, notice: 'Book was successfully updated.' }
format.json { render :show, status: :ok, location: @book }
else
format.html { render :edit }
format.json { render json: @book.errors, status: :unprocessable_entity }
end
end
end

DELETE /books/1

DELETE /books/1.json

def destroy
@book.destroy
respond_to do |format|
format.html { redirect_to books_url, notice: 'Book was successfully destroyed.' }
format.json { head :no_content }
end
end

private
# Use callbacks to share common setup or constraints between actions.
def set_book
@book = Book.find(params[:id])
end

# Never trust parameters from the scary internet, only allow the white list through.
def book_params
  params.require(:book).permit(:title, :author)
end

end

---

また、app/views/books/index.html.erbは下記のようになっております。

class BooksController < ApplicationController
before_action :set_book, only: [:show, :edit, :update, :destroy]

def index
@books = Book.page(params[:page]).per(10)
end

GET /books

GET /books.json

def index
@books = Book.all
end

GET /books/1

GET /books/1.json

def show
end

GET /books/new

def new
@book = Book.new
end

GET /books/1/edit

def edit
end

POST /books

POST /books.json

def create
@book = Book.new(book_params)

respond_to do |format|
  if @book.save
    format.html { redirect_to @book, notice: 'Book was successfully created.' }
    format.json { render :show, status: :created, location: @book }
  else
    format.html { render :new }
    format.json { render json: @book.errors, status: :unprocessable_entity }
  end
end

end

PATCH/PUT /books/1

PATCH/PUT /books/1.json

def update
respond_to do |format|
if @book.update(book_params)
format.html { redirect_to @book, notice: 'Book was successfully updated.' }
format.json { render :show, status: :ok, location: @book }
else
format.html { render :edit }
format.json { render json: @book.errors, status: :unprocessable_entity }
end
end
end

DELETE /books/1

DELETE /books/1.json

def destroy
@book.destroy
respond_to do |format|
format.html { redirect_to books_url, notice: 'Book was successfully destroyed.' }
format.json { head :no_content }
end
end

private
# Use callbacks to share common setup or constraints between actions.
def set_book
@book = Book.find(params[:id])
end

# Never trust parameters from the scary internet, only allow the white list through.
def book_params
  params.require(:book).permit(:title, :author)
end

end

自身でも調べては見たものの、エラーを解決することはできず、多くの場合、別のエラーに変わるだけでした。
そのため、皆様にどこが問題のかを指摘していただく、質問いたしました。
何か情報に不足があれば、お伝え下さい。よろしくお願いいたします。

Answer 1

index アクションが 2 重に定義されています。

def index
  @books = Book.all
end

のほう（つまり，page を使っていないほう）を削除すればいいと思います。