/*
 * Copyright 2002-2016 the original author or authors.
 *
 * 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.springframework.jdbc.core;

import java.sql.ResultSet;
import java.sql.SQLException;

An interface used by JdbcTemplate for processing rows of a ResultSet on a per-row basis. Implementations of this interface perform the actual work of processing each row but don't need to worry about exception handling. SQLExceptions will be caught and handled by the calling JdbcTemplate. 
In contrast to a ResultSetExtractor, a RowCallbackHandler object is typically stateful: It keeps the result state within the object, to be available for later inspection. See RowCountCallbackHandler for a usage example. 
Consider using a RowMapper instead if you need to map exactly one result object per row, assembling them into a List. 
Author:
Rod Johnson, Juergen Hoeller
See Also:
JdbcTemplate
RowMapper
ResultSetExtractor
RowCountCallbackHandler/**
 * An interface used by {@link JdbcTemplate} for processing rows of a
 * {@link java.sql.ResultSet} on a per-row basis. Implementations of
 * this interface perform the actual work of processing each row
 * but don't need to worry about exception handling.
 * {@link java.sql.SQLException SQLExceptions} will be caught and handled
 * by the calling JdbcTemplate.
 *
 * <p>In contrast to a {@link ResultSetExtractor}, a RowCallbackHandler
 * object is typically stateful: It keeps the result state within the
 * object, to be available for later inspection. See
 * {@link RowCountCallbackHandler} for a usage example.
 *
 * <p>Consider using a {@link RowMapper} instead if you need to map
 * exactly one result object per row, assembling them into a List.
 *
 * @author Rod Johnson
 * @author Juergen Hoeller
 * @see JdbcTemplate
 * @see RowMapper
 * @see ResultSetExtractor
 * @see RowCountCallbackHandler
 */
@FunctionalInterface
public interface RowCallbackHandler {

	
Implementations must implement this method to process each row of data in the ResultSet. This method should not call next() on the ResultSet; it is only supposed to extract values of the current row. 
Exactly what the implementation chooses to do is up to it:
A trivial implementation might simply count rows, while another
implementation might build an XML document.
Params:
rs – the ResultSet to process (pre-initialized for the current row)
Throws:
SQLException – if a SQLException is encountered getting
column values (that is, there's no need to catch SQLException)/**
	 * Implementations must implement this method to process each row of data
	 * in the ResultSet. This method should not call {@code next()} on
	 * the ResultSet; it is only supposed to extract values of the current row.
	 * <p>Exactly what the implementation chooses to do is up to it:
	 * A trivial implementation might simply count rows, while another
	 * implementation might build an XML document.
	 * @param rs the ResultSet to process (pre-initialized for the current row)
	 * @throws SQLException if a SQLException is encountered getting
	 * column values (that is, there's no need to catch SQLException)
	 */
	void processRow(ResultSet rs) throws SQLException;

}