# FileConfigurationDataWiper.java

    /*
     * Copyright 2013, Paul Merlin.
     *
     * 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.
     */
    package org.qi4j.library.fileconfig;

    import java.io.File;
    import java.util.ArrayList;
    import java.util.List;
    import org.qi4j.api.activation.ActivationEvent;
    import org.qi4j.api.activation.ActivationEventListener;
    import org.qi4j.api.structure.Application;

    public final class FileConfigurationDataWiper
    {

        public static void registerApplicationPassivationDataWiper( FileConfiguration fileConfig, Application application )
        {
            final List<File> dataDirectories = new ArrayList<File>();
            dataDirectories.add( fileConfig.configurationDirectory() );
            dataDirectories.add( fileConfig.cacheDirectory() );
            dataDirectories.add( fileConfig.dataDirectory() );
            dataDirectories.add( fileConfig.logDirectory() );
            dataDirectories.add( fileConfig.temporaryDirectory() );
            application.registerActivationEventListener( new ActivationEventListener()
            {
                @Override
                public void onEvent( ActivationEvent event )
                {
                    if( event.type() == ActivationEvent.EventType.PASSIVATED && Application.class.isAssignableFrom( event.source().getClass() ) )
                    {
                        for( File dataDir : dataDirectories )
                        {
                            if( !delete( dataDir ) )
                            {
                                System.err.println( "Unable to delete " + dataDir );
                            }
                        }
                    }
                }
            } );
        }

        private static boolean delete( File file )
        {
            if( !file.exists() )
            {
                return true;
            }
            if( file.isFile() )
            {
                return file.delete();
            }
            else
            {
                for( File childFile : file.listFiles() )
                {
                    if( !delete( childFile ) )
                    {
                        return false;
                    }
                }
                return file.delete();
            }
        }

        private FileConfigurationDataWiper()
        {
        }

    }