Java tutorial
/* * 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 * * https://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 {@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 {@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; }