abstractdatasourcefactory.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 java.util.Iterator;

import javax.sql.ConnectionPoolDataSource;
import javax.sql.DataSource;

import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.MappedPropertyDescriptor;
import org.apache.commons.beanutils.PropertyUtils;

import org.apache.commons.configuration.Configuration;
import org.apache.commons.dbcp.cpdsadapter.DriverAdapterCPDS;

import org.apache.commons.lang.StringUtils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.apache.torque.Torque;
import org.apache.torque.TorqueException;

/**
 * A class that contains common functionality of the factories in this
 * package.
 *
 * @author <a href="mailto:[e-mail]">John McNally</a>
 * @author <a href="mailto:[e-mail]">Henning P. Schmiedehausen</a>
 * @version $Id: AbstractDataSourceFactory.java,v 1.15 2005/07/08 17:53:34 tfischer Exp $
 */
public abstract class AbstractDataSourceFactory
        implements DataSourceFactory
{
    /** "pool" Key for the configuration */
    public static final String POOL_KEY = "pool";

    /** "connection" Key for the configuration */
    public static final String CONNECTION_KEY = "connection";

    /** "schema" Key for the configuration */
    public static final String SCHEMA_KEY = "schema";

    /** "defaults" Key for the configuration */
    public static final String DEFAULTS_KEY = "defaults";

    /** "defaults.pool" Key for the configuration */
    public static final String DEFAULT_POOL_KEY 
            = DEFAULTS_KEY + "." + POOL_KEY;

    /** "defaults.connection" Key for the configuration */
    public static final String DEFAULT_CONNECTION_KEY 
            = DEFAULTS_KEY + "." + CONNECTION_KEY;

    /** default schema name for the configuration */
    public static final String DEFAULT_SCHEMA_KEY 
            = DEFAULTS_KEY + "." + SCHEMA_KEY;


    /** The log */
    private static Log log = LogFactory.getLog(AbstractDataSourceFactory.class);

    /** Internal Marker for the Schema name of this database connection */
    private String schema = null;

    /**
     * Encapsulates setting configuration properties on
     * <code>DataSource</code> objects.
     *
     * @param property the property to read from the configuration
     * @param c the configuration to read the property from
     * @param ds the <code>DataSource</code> instance to write the property to
     * @throws Exception if anything goes wrong
     */
    protected void setProperty(String property, Configuration c, Object ds)
        throws Exception
    {
        if (c == null || c.isEmpty())
        {
            return;
        }

        String key = property;
        Class dsClass = ds.getClass();
        int dot = property.indexOf('.');
        try
        {
            if (dot > 0)
            {
                property = property.substring(0, dot);

                MappedPropertyDescriptor mappedPD =
                    new MappedPropertyDescriptor(property, dsClass);
                Class propertyType = mappedPD.getMappedPropertyType();
                Configuration subProps = c.subset(property);
                // use reflection to set properties
                Iterator j = subProps.getKeys();
                while (j.hasNext())
                {
                    String subProp = (String) j.next();
                    String propVal = subProps.getString(subProp);
                    Object value = ConvertUtils.convert(propVal, propertyType);
                    PropertyUtils
                        .setMappedProperty(ds, property, subProp, value);

                    if (log.isDebugEnabled())
                    {
                        log.debug("setMappedProperty("
                                       + ds + ", "
                                       + property + ", "
                                       + subProp + ", "
                                       + value
                                       + ")");
                    }
                }
            }
            else
            {
                if ("password".equals(key)) 
                {
                    // do not log value of password
                    // for this, ConvertUtils.convert cannot be used
                    // as it also logs the value of the converted property
                    // so it is assumed here that the password is a String
                    String value = c.getString(property);
                    PropertyUtils.setSimpleProperty(ds, property, value);
                    if (log.isDebugEnabled())
                    {
                        log.debug("setSimpleProperty("
                                       + ds + ", "
                                       + property + ", "
                                       + " (value not logged)"
                                       + ")");
                    }
                }
                else
                {
                    Class propertyType =
                        PropertyUtils.getPropertyType(ds, property);
                    Object value =
                        ConvertUtils.convert(c.getString(property), propertyType);
                    PropertyUtils.setSimpleProperty(ds, property, value);
    
                    if (log.isDebugEnabled())
                    {
                        log.debug("setSimpleProperty("
                                       + ds + ", "
                                       + property + ", "
                                       + value
                                       + ")");
                    }
                }
            }
        }
        catch (Exception e)
        {
            log.error(
                "Property: "
                + property
                + " value: "
                + c.getString(key)
                + " is not supported by DataSource: "
                + ds.getClass().getName());
        }
    }

    /**
     * Iterate over a Configuration subset and apply all
     * properties to a passed object which must contain Bean
     * setter and getter
     *
     * @param c The configuration subset
     * @param o The object to apply the properties to
     * @throws TorqueException if a property set fails
     */
    protected void applyConfiguration(Configuration c, Object o)
        throws TorqueException
    {
        log.debug("applyConfiguration(" + c + ", " + o + ")");

        if (c != null)
        {
            try
            {
                for (Iterator i = c.getKeys(); i.hasNext();)
                {
                    String key = (String) i.next();
                    setProperty(key, c, o);
                }
            }
            catch (Exception e)
            {
                log.error(e);
                throw new TorqueException(e);
            }
        }
    }
    
    /**
     * Initializes the ConnectionPoolDataSource.
     *
     * @param configuration where to read the settings from
     * @throws TorqueException if a property set fails
     * @return a configured <code>ConnectionPoolDataSource</code>
     */
    protected ConnectionPoolDataSource initCPDS(Configuration configuration)
        throws TorqueException
    {
        log.debug("Starting initCPDS");
        ConnectionPoolDataSource cpds = new DriverAdapterCPDS();
        Configuration c = Torque.getConfiguration();

        if (c == null || c.isEmpty())
        {
            log.warn("Global Configuration not set,"
                    + " no Default connection pool data source configured!");
        }
        else
        {
            Configuration conf = c.subset(DEFAULT_CONNECTION_KEY);
            applyConfiguration(conf, cpds);
        }
            
        Configuration conf = configuration.subset(CONNECTION_KEY);
        applyConfiguration(conf, cpds);
        
        return cpds;
    }

    /**
     * Sets the current schema for the database connection
     *
     * @param schema The current schema name
     */
    public void setSchema(String schema)
    {
        this.schema = 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.
     */
    public String getSchema()
    {
        return schema;
    }

    /**
     * @return the <code>DataSource</code> configured by the factory.
     * @throws TorqueException if the source can't be returned
     */
    public abstract 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.
     */
    public void initialize(Configuration configuration) 
        throws TorqueException
    {
        if (configuration == null)
        {
            throw new TorqueException(
                "Torque cannot be initialized without "
                    + "a valid configuration. Please check the log files "
                    + "for further details.");
        }

        schema = configuration.getString(SCHEMA_KEY, null);

        if (StringUtils.isEmpty(schema))
        {
            Configuration conf = Torque.getConfiguration();
            schema = conf.getString(DEFAULT_SCHEMA_KEY, null);
        }
    }
}