/*
 * Copyright 2002-2017 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.datasource;

import java.sql.Connection;

/**
 * Subinterface of {@link java.sql.Connection} to be implemented by
 * Connection proxies. Allows access to the underlying target Connection.
 *
 * <p>This interface can be checked when there is a need to cast to a
 * native JDBC Connection such as Oracle's OracleConnection. Spring's
 * {@link org.springframework.jdbc.support.nativejdbc.NativeJdbcExtractorAdapter}
 * automatically detects such proxies before delegating to the actual
 * unwrapping for a specific connection pool. Alternatively, all such
 * connections also support JDBC 4.0's {@link Connection#unwrap}.
 *
 * @author Juergen Hoeller
 * @since 1.1
 * @see TransactionAwareDataSourceProxy
 * @see LazyConnectionDataSourceProxy
 * @see DataSourceUtils#getTargetConnection(java.sql.Connection)
 */
public interface ConnectionProxy extends Connection {

	/**
	 * Return the target Connection of this proxy.
	 * <p>This will typically be the native driver Connection
	 * or a wrapper from a connection pool.
	 * @return the underlying Connection (never {@code null})
	 */
	Connection getTargetConnection();

}
