libraries/uowfile/src/main/java/org/apache/zest/library/uowfile/plural/HasUoWFilesLifecycle.java

/*
 * Copyright 2011 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.apache.zest.library.uowfile.plural;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import org.apache.zest.api.entity.Lifecycle;
import org.apache.zest.api.entity.LifecycleException;
import org.apache.zest.api.injection.scope.This;
import org.apache.zest.api.mixin.Mixins;

@Mixins( HasUoWFilesLifecycle.Mixin.class )
public interface HasUoWFilesLifecycle<T extends Enum<T>>
    extends HasUoWFiles<T>, Lifecycle
{
    public class Mixin
        implements Lifecycle
    {
        @This
        private HasUoWFiles<?> hasUoWFiles;

        @Override
        public void create()
            throws LifecycleException
        {
            // NOOP
        }

        @Override
        public void remove()
            throws LifecycleException
        {
            // We use the managed files so that if the UoW gets discarded the files will be restored
            List<File> errors = new ArrayList<>();
            for( File eachFile : hasUoWFiles.managedFiles() )
            {
                if( eachFile.exists() )
                {
                    if( !eachFile.delete() )
                    {
                        errors.add( eachFile );
                    }
                }
            }
            if( !errors.isEmpty() )
            {
                throw new LifecycleException( "Unable to delete existing files: " + errors );
            }
        }
    }

}