# QuestionReplyInstancePreDestruction.java

    /*
     * Copyright (C) 2000 - 2024 Silverpeas
     * <p>
     * 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.
     * <p>
     * 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:
     * "http://www.silverpeas.org/docs/core/legal/floss_exception.html"
     * <p>
     * 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.
     * <p>
     * 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.questionreply;

    import org.silverpeas.core.admin.component.ComponentInstancePreDestruction;
    import org.silverpeas.core.persistence.jdbc.DBUtil;

    import javax.inject.Named;
    import javax.transaction.Transactional;
    import java.sql.Connection;
    import java.sql.PreparedStatement;
    import java.sql.SQLException;

    /**
     * Deletes all the questions and their answers that are managed by the QuestionReply instance that
     * is being deleted.
     * @author mmoquillon
     */
    @Named
    public class QuestionReplyInstancePreDestruction implements ComponentInstancePreDestruction {

      private static final String RECIPIENT_DELETION =
          "DELETE FROM SC_QuestionReply_Recipient WHERE questionId in (SELECT id FROM " +
              "SC_QuestionReply_Question WHERE instanceId = ?)";
      private static final String ANSWER_DELETION =
          "DELETE FROM SC_QuestionReply_Reply WHERE questionId in (SELECT id FROM " +
              "SC_QuestionReply_Question WHERE instanceId = ?)";
      private static final String QUESTION_DELETION =
          "DELETE FROM SC_QuestionReply_Question WHERE instanceId = ?";

      /**
       * Performs pre destruction tasks in the behalf of the specified component instance.
       * @param componentInstanceId the unique identifier of the component instance.
       */
      @Transactional
      @Override
      public void preDestroy(final String componentInstanceId) {
        try (Connection connection = DBUtil.openConnection()) {
          for (String sql : new String[]{RECIPIENT_DELETION, ANSWER_DELETION, QUESTION_DELETION}) {
            try (PreparedStatement deletion = connection.prepareStatement(sql)) {
              deletion.setString(1, componentInstanceId);
              deletion.execute();
            }
          }
        } catch(SQLException e) {
          throw new RuntimeException(e.getMessage(), e);
        }
      }
    }