dbfactory.java

另外一种持久性o/m软件

package org.apache.torque.adapter;

/*
 * 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.util.HashMap;
import java.util.Map;

/**
 * This class creates different {@link org.apache.torque.adapter.DB}
 * objects based on specified JDBC driver name.
 *
 * @author <a href="mailto:[e-mail]">Frank Y. Kim</a>
 * @author <a href="mailto:[e-mail]">Jon S. Stevens</a>
 * @author <a href="mailto:[e-mail]">Brett McLaughlin</a>
 * @author <a href="mailto:[e-mail]">Ralf Stranzenbach</a>
 * @author <a href="mailto:[e-mail]">Daniel Rall</a>
 * @author <a href="mailto:[e-mail]">Henning P. Schmiedehausen</a>
 * @version $Id: DBFactory.java,v 1.37 2005/01/31 19:43:55 tfischer Exp $
 */
public class DBFactory
{
    /**
     * JDBC driver to Torque Adapter map.
     */
    private static Map adapters = new HashMap(40);

    /**
     * Initialize the JDBC driver to Torque Adapter map.
     */
    static
    {
        adapters.put("com.ibm.as400.access.AS400JDBCDriver", DBDB2400.class);
        adapters.put("COM.ibm.db2.jdbc.app.DB2Driver", DBDB2App.class);
        adapters.put("COM.ibm.db2.jdbc.net.DB2Driver", DBDB2Net.class);
        adapters.put("COM.cloudscape.core.JDBCDriver", DBCloudscape.class);
        adapters.put("org.hsql.jdbcDriver", DBHypersonicSQL.class);
        adapters.put("org.hsqldb.jdbcDriver", DBHypersonicSQL.class);
        adapters.put("interbase.interclient.Driver", DBInterbase.class);
        adapters.put("org.enhydra.instantdb.jdbc.idbDriver", DBInstantDB.class);
        adapters.put("com.microsoft.jdbc.sqlserver.SQLServerDriver",
            DBMSSQL.class);
        adapters.put("com.jnetdirect.jsql.JSQLDriver", DBMSSQL.class);
        adapters.put("org.gjt.mm.mysql.Driver", DBMM.class);
        adapters.put("oracle.jdbc.driver.OracleDriver", DBOracle.class);
        adapters.put("org.postgresql.Driver", DBPostgres.class);
        adapters.put("com.sap.dbtech.jdbc.DriverSapDB", DBSapDB.class);
        adapters.put("com.sybase.jdbc.SybDriver", DBSybase.class);
        adapters.put("com.sybase.jdbc2.jdbc.SybDriver", DBSybase.class);
        adapters.put("weblogic.jdbc.pool.Driver", DBWeblogic.class);
        adapters.put("org.axiondb.jdbc.AxionDriver", DBAxion.class);
        adapters.put("com.informix.jdbc.IfxDriver", DBInformix.class);
        adapters.put("sun.jdbc.odbc.JdbcOdbcDriver", DBOdbc.class);

        adapters.put("com.ibm.db2.jcc.DB2Driver", DBDerby.class);
        adapters.put("org.apache.derby.jdbc.EmbeddedDriver", DBDerby.class);


        // add some short names to be used when drivers are not used
        adapters.put("as400", DBDB2400.class);
        adapters.put("db2app", DBDB2App.class);
        adapters.put("db2net", DBDB2Net.class);
        adapters.put("cloudscape", DBCloudscape.class);
        adapters.put("hypersonic", DBHypersonicSQL.class);
        adapters.put("interbase", DBInterbase.class);
        adapters.put("instantdb", DBInstantDB.class);
        adapters.put("mssql", DBMSSQL.class);
        adapters.put("mysql", DBMM.class);
        adapters.put("oracle", DBOracle.class);
        adapters.put("postgresql", DBPostgres.class);
        adapters.put("sapdb", DBSapDB.class);
        adapters.put("sybase", DBSybase.class);
        adapters.put("weblogic", DBWeblogic.class);
        adapters.put("axion", DBAxion.class);
        adapters.put("informix", DBInformix.class);
        adapters.put("odbc", DBOdbc.class);
        adapters.put("msaccess", DBOdbc.class);

        adapters.put("derby", DBDerby.class);

        adapters.put("", DBNone.class);
    }

    /**
     * Creates a new instance of the Torque database adapter associated
     * with the specified JDBC driver or adapter key.
     *
     * @param driver The fully-qualified name of the JDBC driver to
     * create a new adapter instance for or a shorter form adapter key.
     * @return An instance of a Torque database adapter.
     * @throws InstantiationException throws if the JDBC driver could not be
     *      instantiated
     */
    public static DB create(String driver)
        throws InstantiationException
    {
        Class adapterClass = (Class) adapters.get(driver);

        if (adapterClass != null)
        {
            try
            {
                DB adapter = (DB) adapterClass.newInstance();
                // adapter.setJDBCDriver(driver);
                return adapter;
            }
            catch (IllegalAccessException e)
            {
                throw new InstantiationException(
                    "Could not instantiate adapter for JDBC driver: "
                    + driver
                    + ": Assure that adapter bytecodes are in your classpath");
            }
        }
        else
        {
            throw new InstantiationException(
                "Unknown JDBC driver: "
                + driver
                + ": Check your configuration file");
        }
    }
}