001/* 002 * Copyright 2002-2018 the original author or authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * https://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package org.springframework.jdbc.core; 018 019import java.sql.Connection; 020import java.sql.SQLException; 021 022import org.springframework.dao.DataAccessException; 023import org.springframework.lang.Nullable; 024 025/** 026 * Generic callback interface for code that operates on a JDBC Connection. 027 * Allows to execute any number of operations on a single Connection, 028 * using any type and number of Statements. 029 * 030 * <p>This is particularly useful for delegating to existing data access code 031 * that expects a Connection to work on and throws SQLException. For newly 032 * written code, it is strongly recommended to use JdbcTemplate's more specific 033 * operations, for example a {@code query} or {@code update} variant. 034 * 035 * @author Juergen Hoeller 036 * @since 1.1.3 037 * @param <T> the result type 038 * @see JdbcTemplate#execute(ConnectionCallback) 039 * @see JdbcTemplate#query 040 * @see JdbcTemplate#update 041 */ 042@FunctionalInterface 043public interface ConnectionCallback<T> { 044 045 /** 046 * Gets called by {@code JdbcTemplate.execute} with an active JDBC 047 * Connection. Does not need to care about activating or closing the 048 * Connection, or handling transactions. 049 * <p>If called without a thread-bound JDBC transaction (initiated by 050 * DataSourceTransactionManager), the code will simply get executed on the 051 * JDBC connection with its transactional semantics. If JdbcTemplate is 052 * configured to use a JTA-aware DataSource, the JDBC Connection and thus 053 * the callback code will be transactional if a JTA transaction is active. 054 * <p>Allows for returning a result object created within the callback, i.e. 055 * a domain object or a collection of domain objects. Note that there's special 056 * support for single step actions: see {@code JdbcTemplate.queryForObject} 057 * etc. A thrown RuntimeException is treated as application exception: 058 * it gets propagated to the caller of the template. 059 * @param con active JDBC Connection 060 * @return a result object, or {@code null} if none 061 * @throws SQLException if thrown by a JDBC method, to be auto-converted 062 * to a DataAccessException by an SQLExceptionTranslator 063 * @throws DataAccessException in case of custom exceptions 064 * @see JdbcTemplate#queryForObject(String, Class) 065 * @see JdbcTemplate#queryForRowSet(String) 066 */ 067 @Nullable 068 T doInConnection(Connection con) throws SQLException, DataAccessException; 069 070}