org.springframework.jdbc.datasource.ConnectionHolder Maven / Gradle / Ivy
/*
* Copyright 2002-2005 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.datasource;
import java.sql.Connection;
import org.springframework.transaction.support.ResourceHolderSupport;
/**
* Connection holder, wrapping a JDBC Connection.
* DataSourceTransactionManager binds instances of this class
* to the thread, for a given DataSource.
*
* Inherits rollback-only support for nested JDBC transactions
* and reference count functionality from the base class.
*
*
Note: This is an SPI class, not intended to be used by applications.
*
* @author Juergen Hoeller
* @since 06.05.2003
* @see DataSourceTransactionManager
* @see DataSourceUtils
*/
public class ConnectionHolder extends ResourceHolderSupport {
private final ConnectionHandle connectionHandle;
private Connection currentConnection;
/**
* Create a new ConnectionHolder for the given ConnectionHandle.
* @param connectionHandle the ConnectionHandle to hold
*/
public ConnectionHolder(ConnectionHandle connectionHandle) {
this.connectionHandle = connectionHandle;
}
/**
* Create a new ConnectionHolder for the given JDBC Connection,
* wrapping it with a SimpleConnectionHandle.
* @param connection the JDBC Connection to hold
* @see SimpleConnectionHandle
*/
public ConnectionHolder(Connection connection) {
this.connectionHandle = new SimpleConnectionHandle(connection);
}
/**
* Return the ConnectionHandle held by this ConnectionHolder.
*/
public ConnectionHandle getConnectionHandle() {
return connectionHandle;
}
/**
* Return the current Connection held by this ConnectionHolder.
*
This will be the same Connection until released
* gets called on the ConnectionHolder, which will reset the
* held Connection, fetching a new Connection on demand.
* @see ConnectionHandle#getConnection()
* @see #released()
*/
public Connection getConnection() {
if (this.currentConnection == null) {
this.currentConnection = this.connectionHandle.getConnection();
}
return this.currentConnection;
}
/**
* Releases the current Connection held by this ConnectionHolder.
*
This is necessary for ConnectionHandles that expect "Connection borrowing",
* where each returned Connection is only temporarily leased and needs to be
* returned once the data operation is done, to make the Connection available
* for other operations within the same transaction. This is the case with
* JDO 2.0 DataStoreConnections, for example.
* @see org.springframework.orm.jdo.DefaultJdoDialect#getJdbcConnection
*/
public void released() {
super.released();
if (this.currentConnection != null) {
this.connectionHandle.releaseConnection(this.currentConnection);
this.currentConnection = null;
}
}
}