org.camunda.bpm.engine.query.Query Maven / Gradle / Ivy
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* Copyright Camunda Services GmbH and/or licensed to Camunda Services GmbH
* under one or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information regarding copyright
* ownership. Camunda licenses this file to you under the Apache License,
* Version 2.0; 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.camunda.bpm.engine.query;
import java.util.List;
import org.camunda.bpm.engine.BadUserRequestException;
import org.camunda.bpm.engine.ProcessEngineException;
/**
* Describes basic methods for querying.
*
* @author Frederik Heremans
*/
public interface Query, U extends Object> {
/**
* 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();
/** 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 ProcessEngineException when the query results in more than one
* entities.
*/
U singleResult();
/**
* Executes the query and get a list of entities as the result.
*
* @return a list of results
* @throws BadUserRequestException
* When a maximum results limit is specified. A maximum results limit can be specified with
* the process engine configuration property queryMaxResultsLimit (default
* {@link Integer#MAX_VALUE}).
* Please use {@link #listPage(int, int)} instead.
*/
List list();
/**
* Executes the query. No limitation checks are performed (e. g. query limit).
*
* @return a list of results
*/
List unlimitedList();
/**
* Executes the query and get a list of entities as the result.
*
* @param firstResult the index of the first result
* @param maxResults the maximum number of results
* @return a list of results
* @throws BadUserRequestException
* When {@param maxResults} exceeds the maximum results limit. A maximum results limit can
* be specified with the process engine configuration property queryMaxResultsLimit
* (default {@link Integer#MAX_VALUE}).
*/
List listPage(int firstResult, int maxResults);
}