datasourcefactory.java

另外一种持久性o/m软件

package org.apache.torque.dsfactory;

/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * 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.
 */

import javax.sql.DataSource;
import org.apache.commons.configuration.Configuration;
import org.apache.torque.TorqueException;

/**
 * A factory that returns a DataSource.
 *
 * @author <a href="mailto:[e-mail]">John McNally</a>
 * @author <a href="mailto:[e-mail]">Thomas Fischer</a>
 * @version $Id: DataSourceFactory.java,v 1.6 2005/07/08 17:53:34 tfischer Exp $
 */
public interface DataSourceFactory
{
    /**
     * Key for the configuration which contains DataSourceFactories
     */
    public static final String DSFACTORY_KEY = "dsfactory";

    /**
     *  Key for the configuration which contains the fully qualified name
     *  of the factory implementation class 
     */
    public static final String FACTORY_KEY = "factory";
    
    /**
     * @return the <code>DataSource</code> configured by the factory.
     * @throws TorqueException if the source can't be returned
     */
    DataSource getDataSource() throws TorqueException;

    /**
     * Initialize the factory.
     *
     * @param configuration where to load the factory settings from
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    void initialize(Configuration configuration) 
        throws TorqueException;

    /**
     * Sets the current schema for the database connection
     *
     * @param schema The current schema name
     */
    void setSchema(String schema);

    /**
     * This method returns the current schema for the database connection
     *
     * @return The current schema name. Null means, no schema has been set.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    String getSchema();

    /**
     * A hook which is called when the resources of the associated DataSource 
     * can be released.
     * After close() is called, the other methods may not work any more 
     * (e.g. getDataSource() might return null).
     * It is not guaranteed that this method does anything. For example, 
     * we do not want to close connections retrieved via JNDI, so the
     * JndiDataSouurceFactory does not close these connections  
     * 
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    void close()
        throws TorqueException;
    
}