GameService.java

package com.albertfx.games.service;

import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;

import com.albertfx.games.domain.Game;

public interface GameService {
	
	/**
	 * Save a game.
	 *
	 * @param game
	 * the entity to save
	 * @return the persisted entity
	 */
	Game save(Game game);

	/**
	 * Get all the games.
	 *
	 * @param pageable
	 * the pagination information
	 * @return the list of entities
	 */
	Page<Game> findAll(Pageable pageable);

	/**
	 * Get the "id" game.
	 *
	 * @param id 
	 * the id of the entity
	 * @return the entity
	 */
	Game findOne(String id);

	/**
	 * Delete the "id" game.
	 *
	 * @param id 
	 * the id of the entity
	 */
	void delete(String id);
	
}

GameServiceImpl.java

package com.albertfx.games.service.impl;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

import com.albertfx.games.domain.Game;
import com.albertfx.games.repository.GameRepository;
import com.albertfx.games.service.GameService;

@Service
public class GameServiceImpl implements GameService{
	// This is our log tools to register the track of our app
		private final Logger log = LoggerFactory.getLogger(GameService.class);

		private final GameRepository gameRepository;
		
		public GameServiceImpl(GameRepository gameRepository) {
			this.gameRepository = gameRepository;
		}
		
		public Game save(Game game) {
	        log.debug("Request to save Acme : {}", game);
	        // We return our game object with the ID generated
	        return gameRepository.save(game);
		}
		
		/*
		 * Pageable
		 * ----------
		 * Pageable its a type which allow us to access to our data with a pagination.
		 * It takes a track of the page number, the page's size, sorting parameters, etc.
		 * https://docs.spring.io/spring-data/data-commons/docs/current/api/org/springframework/data/domain/Pageable.html
		 * 
		 * Page
		 * ---------
		 * Its a sublist of a list of objects. One of its superinterface are Iterable<T>, so we can access to its data.
		 * It has a track of the total elements or the total pages.
		 * https://docs.spring.io/spring-data/commons/docs/current/api/org/springframework/data/domain/Page.html
		 */
		public Page<Game> findAll(Pageable pageable){
	        log.debug("Request to get all games");
	        return gameRepository.findAll(pageable);
			
		}
		
		 public Game findOne(String id) {
		        log.debug("Request to get game : {}", id);
		        return gameRepository.findOne(id);
		    }
		 
		 
		 public void delete(String id) {
		        log.debug("Request to delete game : {}", id);
		        gameRepository.delete(id);
		    }
}