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* 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
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*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
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package org.apache.cayenne;
import java.util.List;
/**
* Defines API of an iterator over the records returned as a result of
* Select queries execution. Usually a ResultIterator is supported by an open
* java.sql.ResultSet, therefore ResultIterators must be explicitly closed when
* the user is done working with them. An alternative to that is
* {@link ObjectContext#iterate(org.apache.cayenne.query.Select, ResultIteratorCallback)}
* method that handles resource management.
*
* @since 3.0
*/
public interface ResultIterator<T> extends Iterable<T>, AutoCloseable {
/**
* Returns all yet unread rows from ResultSet without closing it.
*
* @since 3.0
*/
List<T> allRows();
/**
* Returns true if there is at least one more record that can be read from
* the iterator.
*/
boolean hasNextRow();
/**
* Returns the next result row that is, depending on the query, may be a
* scalar value, a DataRow, or an Object[] array containing a mix of scalars
* and DataRows.
*
* @since 3.0
*/
T nextRow();
/**
* Goes past current row. If the row is not needed, this may save some time
* on data conversion.
*
* @since 3.0
*/
void skipRow();
/**
* Closes ResultIterator and associated ResultSet. This method must be
* called explicitly when the user is finished processing the records.
* Otherwise unused database resources will not be released properly.
*/
void close();
}