https://github.com/spring-projects/spring-framework: Spring JDBC (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2018 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.SQLException;
import java.sql.Statement;

import org.springframework.dao.DataAccessException;
import org.springframework.lang.Nullable;


Generic callback interface for code that operates on a JDBC Statement. Allows to execute any number of operations on a single Statement, for example a single executeUpdate call or repeated executeUpdate calls with varying SQL. 
Used internally by JdbcTemplate, but also useful for application code.

Author:Juergen Hoeller
Type parameters:
  • <T> – the result type
See Also:
Since:16.03.2004
/**
 * Generic callback interface for code that operates on a JDBC Statement.
 * Allows to execute any number of operations on a single Statement,
 * for example a single {@code executeUpdate} call or repeated
 * {@code executeUpdate} calls with varying SQL.
 *
 * <p>Used internally by JdbcTemplate, but also useful for application code.
 *
 * @author Juergen Hoeller
 * @since 16.03.2004
 * @param <T> the result type
 * @see JdbcTemplate#execute(StatementCallback)
 */
@FunctionalInterface
public interface StatementCallback<T> {

	
Gets called by JdbcTemplate.execute with an active JDBC Statement. Does not need to care about closing the Statement or the Connection, or about handling transactions: this will all be handled by Spring's JdbcTemplate. 
NOTE: Any ResultSets opened should be closed in finally blocks within the callback implementation. Spring will close the Statement object after the callback returned, but this does not necessarily imply that the ResultSet resources will be closed: the Statement objects might get pooled by the connection pool, with close calls only returning the object to the pool but not physically closing the resources. 
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.

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 JdbcTemplate.queryForObject etc.
A thrown RuntimeException is treated as application exception, it gets
propagated to the caller of the template.

Params:
  • stmt – active JDBC Statement
Throws:
  • SQLException – if thrown by a JDBC method, to be auto-converted
to a DataAccessException by a SQLExceptionTranslator
  • DataAccessException – in case of custom exceptions
See Also:
Returns:a result object, or null if none
/**
	 * Gets called by {@code JdbcTemplate.execute} with an active JDBC
	 * Statement. Does not need to care about closing the Statement or the
	 * Connection, or about handling transactions: this will all be handled
	 * by Spring's JdbcTemplate.
	 * <p><b>NOTE:</b> Any ResultSets opened should be closed in finally blocks
	 * within the callback implementation. Spring will close the Statement
	 * object after the callback returned, but this does not necessarily imply
	 * that the ResultSet resources will be closed: the Statement objects might
	 * get pooled by the connection pool, with {@code close} calls only
	 * returning the object to the pool but not physically closing the resources.
	 * <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 JdbcTemplate.queryForObject etc.
	 * A thrown RuntimeException is treated as application exception, it gets
	 * propagated to the caller of the template.
	 * @param stmt active JDBC Statement
	 * @return a result object, or {@code null} 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)
	 */
	@Nullable
	T doInStatement(Statement stmt) throws SQLException, DataAccessException;

}