/*
* Copyright 2002-2008 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.Connection;
import java.sql.SQLException;
import org.springframework.dao.DataAccessException;
/**
* Generic callback interface for code that operates on a JDBC Connection.
* Allows to execute any number of operations on a single Connection,
* using any type and number of Statements.
*
* <p>This is particularly useful for delegating to existing data access code
* that expects a Connection to work on and throws SQLException. For newly
* written code, it is strongly recommended to use JdbcTemplate's more specific
* operations, for example a <code>query</code> or <code>update</code> variant.
*
* @author Juergen Hoeller
* @since 1.1.3
* @see JdbcTemplate#execute(ConnectionCallback)
* @see JdbcTemplate#query
* @see JdbcTemplate#update
*/
public interface ConnectionCallback<T> {
/**
* Gets called by <code>JdbcTemplate.execute</code> with an active JDBC
* Connection. Does not need to care about activating or closing the
* Connection, or handling transactions.
*
* <p>If called without a thread-bound JDBC transaction (initiated by
* DataSourceTransactionManager), the code will simply get executed on the
* JDBC connection with its transactional semantics. If JdbcTemplate is
* configured to use a JTA-aware DataSource, the JDBC Connection and thus
* the callback code will be transactional if a JTA transaction is active.
*
* <p>Allows for returning a result object created within the callback, i.e.
* a domain object or a collection of domain objects. Note that there's special
* support for single step actions: see <code>JdbcTemplate.queryForObject</code>
* etc. A thrown RuntimeException is treated as application exception:
* it gets propagated to the caller of the template.
*
* @param con active JDBC Connection
* @return a result object, or <code>null</code> if none
* @throws SQLException if thrown by a JDBC method, to be auto-converted
* to a DataAccessException by a SQLExceptionTranslator
* @throws DataAccessException in case of custom exceptions
* @see JdbcTemplate#queryForObject(String, Class)
* @see JdbcTemplate#queryForRowSet(String)
*/
T doInConnection(Connection con) throws SQLException, DataAccessException;
}
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