java-design-patterns/partial-response/src/main/java/com/iluwatar/partialresponse/VideoResource.java

/*
 * The MIT License
 * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package com.iluwatar.partialresponse;

import java.util.Map;

/**
 * The resource class which serves video information. This class act as server in the demo. Which
 * has all video details.
 */
public class VideoResource {
  private final FieldJsonMapper fieldJsonMapper;
  private final Map<Integer, Video> videos;

  /**
   * Constructor.
   *
   * @param fieldJsonMapper map object to json.
   * @param videos          initialize resource with existing videos. Act as database.
   */
  public VideoResource(FieldJsonMapper fieldJsonMapper, Map<Integer, Video> videos) {
    this.fieldJsonMapper = fieldJsonMapper;
    this.videos = videos;
  }

  /**
   * Get Details.
   *
   * @param id     video id
   * @param fields fields to get information about
   * @return full response if no fields specified else partial response for given field.
   */
  public String getDetails(Integer id, String... fields) throws Exception {
    if (fields.length == 0) {
      return videos.get(id).toString();
    }
    return fieldJsonMapper.toJson(videos.get(id), fields);
  }
}