torque.java

另外一种持久性o/m软件

package org.apache.torque;

/*
 * 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 java.sql.Connection;

import org.apache.commons.configuration.Configuration;

import org.apache.torque.adapter.DB;
import org.apache.torque.manager.AbstractBaseManager;
import org.apache.torque.map.DatabaseMap;

/**
 * A static facade wrapper around the Torque implementation (which is in
 * {@link org.apache.torque.TorqueInstance}).
 * <br/>
 *
 * @author <a href="mailto:[e-mail]">Daniel Rall</a>
 * @author <a href="mailto:[e-mail]">Magn�s ��r Torfason</a>
 * @author <a href="mailto:[e-mail]">Jason van Zyl</a>
 * @author <a href="mailto:[e-mail]">Rafal Krzewski</a>
 * @author <a href="mailto:[e-mail]">Martin Poeschl</a>
 * @author <a href="mailto:[e-mail]">Henning P. Schmiedehausen</a>
 * @author <a href="mailto:[e-mail]">Kurt Schrader</a>
 * @version $Id: Torque.java,v 1.96 2005/07/08 17:53:34 tfischer Exp $
 */
public abstract class Torque
{
    /**
     * The prefix for all configuration keys used by Torque
     */
    public static final String TORQUE_KEY = "torque";

    /**
     * the prefix for configuring the database adapters and the default database
     */
    public static final String DATABASE_KEY = "database";

    /**
     * The key used to configure the name of the default database
     */
    public static final String DEFAULT_KEY = "default";

    /**
     * Name of property that specifies the default map builder and map.
     * @deprecated is not used any more. Use DATABASE_KEY and 
     *             DEFAULT_KEY instead
     */
    public static final String DATABASE_DEFAULT 
            = DATABASE_KEY + "." + DEFAULT_KEY;

    /**
     * A prefix for <code>Manager</code> properties in the configuration.
     */
    public static final String MANAGER_PREFIX = "managed_class.";

    /**
     * A <code>Service</code> property determining its implementing
     * class name .
     */
    public static final String MANAGER_SUFFIX = ".manager";

    /**
     * property to determine whether caching is used.
     */
    public static final String CACHE_KEY = "manager.useCache";

    /**
     * The single instance of {@link TorqueInstance} used by the
     * static API presented by this class.
     */
    private static TorqueInstance torqueSingleton = null;

    /**
     * C'tor for usage with the Stratum Lifecycle.
     *
     * @todo Should be made private or protected once Stratum is removed.
     */
    public Torque()
    {
    }

    /**
     * Retrieves the single {@link org.apache.torque.TorqueInstance}
     * used by this class.
     *
     * @return Our singleton.
     */
    public static TorqueInstance getInstance()
    {
        if (torqueSingleton == null)
        {
            torqueSingleton = new TorqueInstance();
        }
        return torqueSingleton;
    }

    /**
     * Initialization of Torque with a properties file.
     *
     * @param configFile The absolute path to the configuration file.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static void init(String configFile)
        throws TorqueException
    {
        getInstance().init(configFile);
    }

    /**
     * Initialization of Torque with a properties file.
     *
     * @param conf The Torque configuration.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static void init(Configuration conf)
        throws TorqueException
    {
        getInstance().init(conf);
    }

    /**
     * Determine whether Torque has already been initialized.
     *
     * @return true if Torque is already initialized
     */
    public static boolean isInit()
    {
        return getInstance().isInit();
    }

    /**
     * Sets the configuration for Torque and all dependencies.
     *
     * @param conf the Configuration
     */
    public static void setConfiguration(Configuration conf)
    {
        getInstance().setConfiguration(conf);
    }

    /**
     * Get the configuration for this component.
     *
     * @return the Configuration
     */
    public static Configuration getConfiguration()
    {
        return getInstance().getConfiguration();
    }

    /**
     * This method returns a Manager for the given name.
     *
     * @param name name of the manager
     * @return a Manager
     */
    public static AbstractBaseManager getManager(String name)
    {
        return getInstance().getManager(name);
    }

    /**
     * This methods returns either the Manager from the configuration file,
     * or the default one provided by the generated code.
     *
     * @param name name of the manager
     * @param defaultClassName the class to use if name has not been configured
     * @return a Manager
     */
    public static AbstractBaseManager getManager(String name,
            String defaultClassName)
    {
        return getInstance().getManager(name, defaultClassName);
    }

    /**
     * Shuts down the service.
     *
     * This method halts the IDBroker's daemon thread in all of
     * the DatabaseMap's. It also closes all SharedPoolDataSourceFactories
     * and PerUserPoolDataSourceFactories initialized by Torque.
     * @exception TorqueException if a DataSourceFactory could not be closed 
     *            cleanly. Only the first exception is rethrown, any following 
     *            exceptions are logged but ignored.
     */
    public static void shutdown()
        throws TorqueException
    {
        getInstance().shutdown();
    }

    /**
     * Returns the default database map information.
     *
     * @return A DatabaseMap.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static DatabaseMap getDatabaseMap()
        throws TorqueException
    {
        return getInstance().getDatabaseMap();
    }

    /**
     * Returns the database map information. Name relates to the name
     * of the connection pool to associate with the map.
     *
     * @param name The name of the database corresponding to the
     *        <code>DatabaseMap</code> to retrieve.
     * @return The named <code>DatabaseMap</code>.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static DatabaseMap getDatabaseMap(String name)
        throws TorqueException
    {
        return getInstance().getDatabaseMap(name);
    }

    /**
     * Register a MapBuilder
     *
     * @param className the MapBuilder
     */
    public static void registerMapBuilder(String className)
    {
        getInstance().registerMapBuilder(className);
    }

    /**
     * This method returns a Connection from the default pool.
     *
     * @return The requested connection.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static Connection getConnection()
        throws TorqueException
    {
        return getInstance().getConnection();
    }

    /**
     * This method returns a Connecton using the given database name.
     *
     * @param name The database name.
     * @return a database connection
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static Connection getConnection(String name)
        throws TorqueException
    {
        return getInstance().getConnection(name);
    }

    /**
     * This method returns a Connecton using the given parameters.
     * You should only use this method if you need user based access to the
     * database!
     *
     * @param name The database name.
     * @param username The name of the database user.
     * @param password The password of the database user.
     * @return A Connection.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static Connection getConnection(String name, String username,
            String password)
            throws TorqueException
    {
        return getInstance().getConnection(name, username, password);
    }
    /**
     * Returns database adapter for a specific connection pool.
     *
     * @param name A pool name.
     * @return The corresponding database adapter.
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static DB getDB(String name) throws TorqueException
    {
        return getInstance().getDB(name);
    }

    /**
     * Returns the name of the default database.
     *
     * @return name of the default DB, or null if Torque is not initialized yet
     */
    public static String getDefaultDB()
    {
        return getInstance().getDefaultDB();
    }

    /**
     * Closes a connection.
     *
     * @param con A Connection to close.
     */
    public static void closeConnection(Connection con)
    {
        getInstance().closeConnection(con);
    }

    /**
     * Sets the current schema for a database connection
     *
     * @param name The database name.
     * @param schema The current schema name
     * @throws TorqueException Any exceptions caught during processing will be
     *         rethrown wrapped into a TorqueException.
     */
    public static void setSchema(String name, String schema)
            throws TorqueException
    {
        getInstance().setSchema(name, schema);
    }

    /**
     * This method returns the current schema for a database connection
     *
     * @param name The database name.
     * @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.
     */
    public static String getSchema(String name)
        throws TorqueException
    {
        return getInstance().getSchema(name);
    }
}