content: /*
   * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
   *
   * Licensed 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.activiti.engine.query;
  
  import java.util.List;
  import org.activiti.engine.ActivitiException;
  import org.activiti.engine.api.internal.Internal;
  
  /**
   * Describes basic methods for querying.
   *
   */
  @Internal
  public interface Query<T extends Query<?, ?>, U> {
      /**
       * Order the results ascending on the given property as defined in this class (needs to come after a call to one of the orderByXxxx methods).
       */
      T asc();
  
      /**
       * Order the results descending on the given property as defined in this class (needs to come after a call to one of the orderByXxxx methods).
       */
      T desc();
  
      /**
       * Order the results by the given {@link QueryProperty} (needs to be followed by {@link #asc()} or {@link #desc()})
       * @param property the {@code QueryProperty} to be used to order the results
       * @return itself
       */
      T orderBy(QueryProperty property);
  
      /** Executes the query and returns the number of results */
      long count();
  
      /**
       * Executes the query and returns the resulting entity or null if no entity matches the query criteria.
       *
       * @throws ActivitiException
       *           when the query results in more than one entities.
       */
      U singleResult();
  
      /** Executes the query and get a list of entities as the result. */
      List<U> list();
  
      /** Executes the query and get a list of entities as the result. */
      List<U> listPage(int firstResult, int maxResults);
  }
  