Java tutorial
/* * 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 * * 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.CallableStatement; import java.sql.SQLException; import org.springframework.dao.DataAccessException; import org.springframework.lang.Nullable; /** * Generic callback interface for code that operates on a CallableStatement. * Allows to execute any number of operations on a single CallableStatement, * for example a single execute call or repeated execute calls with varying * parameters. * * <p>Used internally by JdbcTemplate, but also useful for application code. * Note that the passed-in CallableStatement can have been created by the * framework or by a custom CallableStatementCreator. However, the latter is * hardly ever necessary, as most custom callback actions will perform updates * in which case a standard CallableStatement is fine. Custom actions will * always set parameter values themselves, so that CallableStatementCreator * capability is not needed either. * * @author Juergen Hoeller * @since 16.03.2004 * @param <T> the result type * @see JdbcTemplate#execute(String, CallableStatementCallback) * @see JdbcTemplate#execute(CallableStatementCreator, CallableStatementCallback) */ @FunctionalInterface public interface CallableStatementCallback<T> { /** * Gets called by {@code JdbcTemplate.execute} with an active JDBC * CallableStatement. 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. A thrown RuntimeException * is treated as application exception: it gets propagated to the caller of * the template. * * @param cs active JDBC CallableStatement * @return a result object, or {@code null} if none * @throws SQLException if thrown by a JDBC method, to be auto-converted * into a DataAccessException by a SQLExceptionTranslator * @throws DataAccessException in case of custom exceptions */ @Nullable T doInCallableStatement(CallableStatement cs) throws SQLException, DataAccessException; }