repositorymanager.java

java 开发的邮件服务器平台。支持以下协议。 协议可以修改为自己的专门标识

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 * Copyright (c) 2000-2004 The Apache Software Foundation.             *
 * All rights reserved.                                                *
 * ------------------------------------------------------------------- *
 * 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                      *
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 * 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.                      *
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package org.apache.james.mailrepository.filepair;

import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import org.apache.avalon.cornerstone.services.store.Repository;
import org.apache.avalon.cornerstone.services.store.Store;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.Component;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.context.Context;
import org.apache.avalon.framework.context.Contextualizable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.container.ContainerUtil;

/**
 * @phoenix:block
 * @phoenix:service name="org.apache.avalon.cornerstone.services.store.Store"
 *
 */
public class RepositoryManager
    extends AbstractLogEnabled
    implements Store, Contextualizable, Composable, Serviceable, Configurable
{
    private static final String REPOSITORY_NAME = "Repository";
    private static long id = 0;

    protected HashMap m_repositories = new HashMap();
    protected HashMap m_models = new HashMap();
    protected HashMap m_classes = new HashMap();
    protected ComponentManager m_componentManager;
    protected ServiceManager m_serviceManager;
    protected Context m_context;

    public void contextualize( final Context context )
    {
        m_context = context;
    }

    public void compose( final ComponentManager componentManager )
        throws ComponentException
    {
        m_componentManager = componentManager;
    }

    public void service( final ServiceManager serviceManager )
        throws ServiceException
    {
        m_serviceManager = serviceManager;
    }

    public void configure( final Configuration configuration )
        throws ConfigurationException
    {
        final Configuration[] registeredClasses =
            configuration.getChild( "repositories" ).getChildren( "repository" );

        for( int i = 0; i < registeredClasses.length; i++ )
        {
            registerRepository( registeredClasses[ i ] );
        }
    }

    public void registerRepository( final Configuration repConf )
        throws ConfigurationException
    {
        final String className = repConf.getAttribute( "class" );
        getLogger().info( "Registering Repository " + className );

        final Configuration[] protocols =
            repConf.getChild( "protocols" ).getChildren( "protocol" );
        final Configuration[] types = repConf.getChild( "types" ).getChildren( "type" );
        final Configuration[] modelIterator =
            repConf.getChild( "models" ).getChildren( "model" );

        for( int i = 0; i < protocols.length; i++ )
        {
            final String protocol = protocols[ i ].getValue();

            for( int j = 0; j < types.length; j++ )
            {
                final String type = types[ j ].getValue();

                for( int k = 0; k < modelIterator.length; k++ )
                {
                    final String model = modelIterator[ k ].getValue();
                    m_classes.put( protocol + type + model, className );
                    getLogger().info( "   for " + protocol + "," + type + "," + model );
                }
            }
        }
    }

    public void release( final Component component )
    {
    }

    public boolean hasComponent( final Object hint )
    {
        if( hint instanceof Configuration )
            return true;
        else
            return false;
    }

    public boolean isSelectable( final Object hint )
    {
        if( hint instanceof Configuration )
            return true;
        else
            return false;
    }

    public Component select( final Object hint )
        throws ComponentException
    {
        Configuration repConf = null;
        try
        {
            repConf = (Configuration)hint;
        }
        catch( final ClassCastException cce )
        {
            throw new ComponentException( "Hint is of the wrong type. " +
                                          "Must be a Configuration", cce );
        }

        URL destination = null;
        try
        {
            destination = new URL( repConf.getAttribute( "destinationURL" ) );
        }
        catch( final ConfigurationException ce )
        {
            throw new ComponentException( "Malformed configuration has no " +
                                          "destinationURL attribute", ce );
        }
        catch( final MalformedURLException mue )
        {
            throw new ComponentException( "destination is malformed. " +
                                          "Must be a valid URL", mue );
        }

        try
        {
            final String type = repConf.getAttribute( "type" );
            final String repID = destination + type;
            Repository reply = (Repository)m_repositories.get( repID );
            final String model = (String)repConf.getAttribute( "model" );

            if( null != reply )
            {
                if( m_models.get( repID ).equals( model ) )
                {
                    return reply;
                }
                else
                {
                    final String message = "There is already another repository with the " +
                        "same destination and type but with different model";
                    throw new ComponentException( message );
                }
            }
            else
            {
                final String protocol = destination.getProtocol();
                final String repClass = (String)m_classes.get( protocol + type + model );

                getLogger().debug( "Need instance of " + repClass + " to handle: " +
                                   protocol + type + model );

                try
                {
                    reply = (Repository)Class.forName( repClass ).newInstance();
                    setupLogger( reply, "repository" );

                    ContainerUtil.contextualize(reply, m_context);
                    ContainerUtil.compose(reply, m_componentManager);
                    ContainerUtil.service(reply, m_serviceManager);
                    ContainerUtil.configure(reply, repConf);
                    ContainerUtil.initialize(reply);

                    m_repositories.put( repID, reply );
                    m_models.put( repID, model );
                    getLogger().info( "New instance of " + repClass + " created for " +
                                      destination );
                    return reply;
                }
                catch( final Exception e )
                {
                    final String message = "Cannot find or init repository: " + e.getMessage();
                    getLogger().warn( message, e );

                    throw new ComponentException( message, e );
                }
            }
        }
        catch( final ConfigurationException ce )
        {
            throw new ComponentException( "Malformed configuration", ce );
        }
    }

    public static final String getName()
    {
        return REPOSITORY_NAME;
    }
}