content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.ambari.view.migration;
  
  /**
   * Interface for data migration logic class.
   */
  public interface ViewDataMigrator {
    /**
     * Called by the view framework before migration process. View can cancel migration by returning false.
     *
     * @return  true if view can do the migration, false otherwise.
     * @throws  ViewDataMigrationException   migration exception occurred.
     */
    boolean beforeMigration() throws ViewDataMigrationException;
  
    /**
     * Called by the view framework after migration finished.
     * View can do cleanup and additional migration procedures.
     *
     * @throws ViewDataMigrationException    migration exception occurred.
     */
    void afterMigration() throws ViewDataMigrationException;
  
    /**
     * Called by the view framework during migration process for every persistence entity
     * of the origin (source) instance.
     * View can migrate a single persistence entity in the implementation of this method.
     *
     * @param originEntityClass    class object of origin (migration source) instance
     * @param currentEntityClass   class object of current (migration target) instance
     *
     * @throws ViewDataMigrationException    migration exception occurred.
     */
    void migrateEntity(Class originEntityClass, Class currentEntityClass) throws ViewDataMigrationException;
  
    /**
     * Called by the view framework during migration process.
     * View can migrate the instance data in the implementation of this method.
     *
     * @throws ViewDataMigrationException    migration exception occurred.
     */
    void migrateInstanceData() throws ViewDataMigrationException;
  }
  