# ResourceUtil.java

    /*
     * Copyright (C) 2000 - 2024 Silverpeas
     *
     * This program is free software: you can redistribute it and/or modify
     * it under the terms of the GNU Affero General Public License as
     * published by the Free Software Foundation, either version 3 of the
     * License, or (at your option) any later version.
     *
     * As a special exception to the terms and conditions of version 3.0 of
     * the GPL, you may redistribute this Program in connection with Free/Libre
     * Open Source Software ("FLOSS") applications as described in Silverpeas's
     * FLOSS exception. You should have received a copy of the text describing
     * the FLOSS exception, and it is also available here:
     * "https://www.silverpeas.org/legal/floss_exception.html"
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     * GNU Affero General Public License for more details.
     *
     * You should have received a copy of the GNU Affero General Public License
     * along with this program. If not, see <https://www.gnu.org/licenses/>.
     */
    package org.silverpeas.components.resourcesmanager.util;

    import org.silverpeas.components.resourcesmanager.model.Resource;
    import org.silverpeas.kernel.util.StringUtil;

    import java.util.ArrayList;
    import java.util.List;
    import java.util.StringTokenizer;

    /**
     * User: Yohann Chastagnier
     * Date: 04/04/13
     */
    public class ResourceUtil {

      private ResourceUtil() {
      }

      /**
       * Get a list of resource identifiers from a list of resource.
       * @param resources a list of resources.
       * @return a list of the resources' identifiers.
       */
      public static List<Long> toIdList(List<Resource> resources) {
        List<Long> result = new ArrayList<>();
        if (resources != null && !resources.isEmpty()) {
          for (Resource resource : resources) {
            result.add(resource.getIdAsLong());
          }
        }
        return result;
      }

      /**
       * Get a list of resource identifiers from a string containing resource identifiers separated by
       * comma.
       * @param stringOfIds a string encoding a comma-separator list of resources' identifiers.
       * @return the list of the resources' identifiers.
       */
      public static List<Long> toIdList(String stringOfIds) {
        List<Long> result = new ArrayList<>();
        if (StringUtil.isDefined(stringOfIds)) {
          StringTokenizer tokenizer = new StringTokenizer(stringOfIds, ",");
          while (tokenizer.hasMoreTokens()) {
            result.add(Long.parseLong(tokenizer.nextToken()));
          }
        }
        return result;
      }
    }