    001    //  Copyright 2008, 2009 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.upload.internal.services;
    016
    017    import org.apache.commons.fileupload.FileUploadException;
    018    import org.apache.tapestry5.annotations.Events;
    019    import org.apache.tapestry5.internal.services.ComponentResultProcessorWrapper;
    020    import org.apache.tapestry5.ioc.annotations.Primary;
    021    import org.apache.tapestry5.runtime.Component;
    022    import org.apache.tapestry5.services.*;
    023    import org.apache.tapestry5.upload.services.MultipartDecoder;
    024    import org.apache.tapestry5.upload.services.UploadEvents;
    025
    026    import java.io.IOException;
    027
    028    /**
    029     * Determines if there was an {@link org.apache.commons.fileupload.FileUploadException} processing the request and, if
    030     * so, triggers an exception event on the page. If the page fails to respond to the event, then
    031     */
    032    @Events(UploadEvents.UPLOAD_EXCEPTION + " when a exception occur processing the upload")
    033    public class UploadExceptionFilter implements ComponentEventRequestFilter
    034    {
    035        private final MultipartDecoder decoder;
    036
    037        private final ComponentEventResultProcessor resultProcessor;
    038
    039        private ComponentSource componentSource;
    040
    041        public UploadExceptionFilter(MultipartDecoder decoder,
    042                                     @Traditional @Primary ComponentEventResultProcessor resultProcessor,
    043                                     ComponentSource componentSource)
    044        {
    045            this.decoder = decoder;
    046            this.resultProcessor = resultProcessor;
    047            this.componentSource = componentSource;
    048        }
    049
    050        public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
    051                throws IOException
    052        {
    053            FileUploadException uploadException = decoder.getUploadException();
    054
    055            if (uploadException != null)
    056            {
    057                Component page = componentSource.getPage(parameters.getActivePageName());
    058
    059                ComponentResultProcessorWrapper callback = new ComponentResultProcessorWrapper(resultProcessor);
    060
    061                page.getComponentResources().triggerEvent(UploadEvents.UPLOAD_EXCEPTION, new Object[] { uploadException },
    062                                                          callback);
    063
    064                // If an event handler exists and returns a value, then the callback will be aborted and a response
    065                // (typically a redirect) will already have been sent to the client.
    066
    067                if (callback.isAborted()) return;
    068
    069                // If the page does not properly handle the exception, then we throw it now.
    070
    071                throw new RuntimeException(UploadMessages.unableToDecode(), uploadException);
    072            }
    073
    074
    075            handler.handle(parameters);
    076        }
    077    }