com.mysql.cj.xdevapi.FetchResult Maven / Gradle / Ivy
/*
* Copyright (c) 2015, 2020, Oracle and/or its affiliates.
*
* This program is free software; you can redistribute it and/or modify it under
* the terms of the GNU General Public License, version 2.0, as published by the
* Free Software Foundation.
*
* This program is also distributed with certain software (including but not
* limited to OpenSSL) that is licensed under separate terms, as designated in a
* particular file or component or in included license documentation. The
* authors of MySQL hereby grant you an additional permission to link the
* program and your derivative works with the separately licensed software that
* they have included with MySQL.
*
* Without limiting anything contained in the foregoing, this file, which is
* part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
* version 1.0, a copy of which can be found at
* http://oss.oracle.com/licenses/universal-foss-exception.
*
* 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 General Public License, version 2.0,
* for more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package com.mysql.cj.xdevapi;
import java.util.Iterator;
import java.util.List;
/**
* A set of elements from a query command.
*
* @param
* the type of element returned from the query (doc or row)
*/
public interface FetchResult extends Iterator, Iterable {
/**
* Does this result have data? This indicates that the result was produced from a data-returning query. It does not indicate whether there are more than 0
* rows in the result.
*
* @return true if has data
*/
default boolean hasData() {
return true;
}
/**
* Fetch the next element.
*
* @return element of type T
*/
default T fetchOne() {
if (hasNext()) {
return next();
}
return null;
}
/**
* Create an iterator over all elements of the result.
*
* @return iterator over result items
*/
default Iterator iterator() {
return fetchAll().iterator();
}
/**
* How many items are in this result? This method forces internal buffering of the entire result.
*
* @return number of elements in result
*/
long count();
/**
* Create a list of all elements in the result forcing internal buffering.
*
* @return list of result elements
*/
List fetchAll();
}