org.springframework.jdbc.core.RowMapper Maven / Gradle / Ivy
/*
* Copyright 2002-2023 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;
import org.springframework.lang.Nullable;
/**
* An interface used by {@link JdbcTemplate} for mapping rows of a
* {@link java.sql.ResultSet} on a per-row basis. Implementations of this
* interface perform the actual work of mapping each row to a result object
* but don't need to worry about exception handling.
* {@link java.sql.SQLException SQLExceptions} will be caught and handled
* by the calling {@code JdbcTemplate}.
*
* Typically used either for {@code JdbcTemplate}'s query methods or for
* {@code out} parameters of stored procedures. {@code RowMapper} objects are
* typically stateless and thus reusable; they are an ideal choice for
* implementing row-mapping logic in a single place.
*
*
Alternatively, consider subclassing
* {@link org.springframework.jdbc.object.MappingSqlQuery} from the
* {@code jdbc.object} package: instead of working with separate
* {@code JdbcTemplate} and {@code RowMapper} objects, you can build executable
* query objects (containing row-mapping logic) in that style.
*
* @author Thomas Risberg
* @author Juergen Hoeller
* @param the result type
* @see JdbcTemplate
* @see RowCallbackHandler
* @see ResultSetExtractor
* @see org.springframework.jdbc.object.MappingSqlQuery
*/
@FunctionalInterface
public interface RowMapper {
/**
* Implementations must implement this method to map each row of data in the
* {@code ResultSet}. This method should not call {@code next()} on the
* {@code ResultSet}; it is only supposed to map values of the current row.
* @param rs the {@code ResultSet} to map (pre-initialized for the current row)
* @param rowNum the number of the current row
* @return the result object for the current row (may be {@code null})
* @throws SQLException if an SQLException is encountered while getting
* column values (that is, there's no need to catch SQLException)
*/
@Nullable
T mapRow(ResultSet rs, int rowNum) throws SQLException;
}