contrib/TurbineYaafiComponentService.java

package org.apache.turbine.services.yafficomponent;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.io.File;
import java.io.IOException;

import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.logger.Log4JLogger;
import org.apache.commons.configuration2.Configuration;
import org.apache.fulcrum.yaafi.framework.container.ServiceContainer;
import org.apache.fulcrum.yaafi.framework.factory.ServiceContainerConfiguration;
import org.apache.fulcrum.yaafi.framework.factory.ServiceContainerFactory;
import org.apache.log4j.Logger;
import org.apache.turbine.Turbine;
import org.apache.turbine.services.InitializationException;
import org.apache.turbine.services.TurbineBaseService;
import org.apache.turbine.services.servlet.TurbineServlet;

/**
 * An implementation of Turbine service initializing the YAAFI container
 *
 * @author <a href="mailto:siegfried.goescfl@it20one.at">Siegfried Goeschl</a>
 */
public class TurbineYaafiComponentService
        extends TurbineBaseService
        implements YaafiComponentService, Initializable, Disposable
{
	/** property to lookup the container configuration file */
	public final String CONTAINER_CONFIGURATION_KEY = "containerConfiguration";

	/** the default value for the container configuration file */
	public final String CONTAINER_CONFIGURATION_VALUE = "/WEB-INF/conf/containerConfiguration.xml";

    /** property to lookup the properties file */
	public final String COMPONENT_PARAMETERS_KEY = "parameters";

	/** the default value for the parameter file */
	public final String COMPONENT_PARAMETERS_VALUE = "/WEB-INF/conf/parameters.properties";

    /** YAFFI container */
    private ServiceContainer container;

    /** our Log4J logger */
    private Logger logger;

    // -------------------------------------------------------------
    // Service initialization
    // -------------------------------------------------------------

    public TurbineYaafiComponentService()
    {
        this.logger = Logger.getLogger(TurbineYaafiComponentService.class);
    }

    /**
     * Load all configured components and initialize them. This is a zero parameter variant which
     * queries the Turbine Servlet for its config.
     *
     * @throws InitializationException Something went wrong in the init stage
     */
    public void init( Object data )
        throws InitializationException
    {
        try
        {
            this.logger.info( "Initializing TurbineYaafiComponentService ..." );
            initialize();
            setInit(true);
        }
        catch (Exception e)
        {
            this.logger.error("Exception caught initialising service: ", e);
            throw new InitializationException("Initializing TurbineYaafiComponentService failed", e);
        }
    }

    /**
     * Shuts the Component Service down, calls dispose on the components that implement this
     * interface
     *
     */
    public void shutdown()
    {
        this.logger.info( "Disposing TurbineYaafiComponentService ..." );
        dispose();
        setInit(false);
    }

    // -------------------------------------------------------------
    // Avalon lifecycle interfaces
    // -------------------------------------------------------------

    /**
     * Initializes the container
     *
     * @throws Exception generic exception
     */
    public void initialize() throws Exception
    {
        // get the configuration from the baseclass

        Configuration conf = this.getConfiguration();

        // if we are not running witin a servlet we get a null string here !!!

        String homePath = TurbineServlet.getRealPath ("/");

        if( homePath == null )
        {
            homePath = Turbine.getApplicationRoot();
        }

        // determine the home directory

        File home = new File(homePath);

        this.logger.info( "Using the following home : " + home.getAbsolutePath() );

        // create the configuration for YAAFI

        ServiceContainerConfiguration config = this.createServiceContainerConfiguration(conf);

        config.setLogger( this.createAvalonLogger( "yaafi" ) );
        config.setApplicationRootDir( home );

        try
        {
            this.container = ServiceContainerFactory.create(
                config
                );
        }
        catch (Throwable t)
        {
            String msg = "Initializing YAAFI failed";
            this.logger.error(msg,t);
        }
    }

    /**
     * Disposes of the container and releases resources
     */
    public void dispose()
    {
        if (this.container != null)
        {
            this.container.dispose();
            this.container = null;
        }
    }

    /**
     * Returns an instance of the named component
     *
     * @param roleName Name of the role the component fills.
     * @return an instance of the named component
     * @throws Exception generic exception
     */
    public Object lookup(String path) throws Exception
    {
        return this.container.lookup(path);
    }

    /**
     * Releases the component
     *
     * @param source. The path to the handler for this component For example, if the object is a
     *            java.sql.Connection object sourced from the "/turbine-merlin/datasource"
     *            component, the call would be :- release("/turbine-merlin/datasource", conn);
     * @param component the component to release
     */
    public void release(Object component)
    {
        this.container.release( component );
    }

    /**
     * Create a ServiceContainerConfiguration based on the Turbine configuration
     *
     * @param conf the Turbine configuration
     * @return the YAAFI configuration
     * @throws IOException creating the YAAFI configuration failed
     */
    protected ServiceContainerConfiguration createServiceContainerConfiguration( Configuration conf )
    	throws IOException
    {
        ServiceContainerConfiguration result = new ServiceContainerConfiguration();

        // are we using a "containerConfiguration.xml" ?!

        if( conf.containsKey(CONTAINER_CONFIGURATION_KEY) )
        {
	        // determine the container configuration file

	        String containerConfiguration = conf.getString(
	            CONTAINER_CONFIGURATION_KEY
	            );

	        result.loadContainerConfiguration(containerConfiguration);
        }
	    else if( conf.containsKey(COMPONENT_ROLE_KEY) )
	    {
	        // determine the location of the role configuraton file

	        String roleConfigurationFileName = conf.getString(
	            COMPONENT_ROLE_KEY,
	            COMPONENT_ROLE_VALUE
	            );

	        // determine the location of component configuration file

	        String componentConfigurationFileName = conf.getString(
	            COMPONENT_CONFIG_KEY,
	            COMPONENT_CONFIG_VALUE
	            );

	        // determine the location of parameters file

	        String parametersFileName = conf.getString(
	            COMPONENT_PARAMETERS_KEY,
	            COMPONENT_PARAMETERS_VALUE
	            );

	        result.setComponentRolesLocation( roleConfigurationFileName );
	        result.setComponentConfigurationLocation( componentConfigurationFileName );
	        result.setParametersLocation( parametersFileName );
	    }
	    else
        {
	        // determine the container configuration file

	        String containerConfiguration = conf.getString(
	            CONTAINER_CONFIGURATION_KEY,
	            CONTAINER_CONFIGURATION_VALUE
	            );

	        result.loadContainerConfiguration(containerConfiguration);
        }

        return result;
    }

    /**
     * Create the Avalon logger to be passed to YAAFI
     * @param name the name of the logger
     * @return an Avalon Logger
     */
    protected org.apache.avalon.framework.logger.Logger createAvalonLogger( String name )
    {
        return new Log4JLogger( Logger.getLogger( name ) );
    }
}