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
015package org.apache.tapestry5.upload.internal.services;
016
017import org.apache.commons.fileupload.FileUploadException;
018import org.apache.tapestry5.annotations.Events;
019import org.apache.tapestry5.internal.services.ComponentResultProcessorWrapper;
020import org.apache.tapestry5.ioc.annotations.Primary;
021import org.apache.tapestry5.runtime.Component;
022import org.apache.tapestry5.services.*;
023import org.apache.tapestry5.upload.services.MultipartDecoder;
024import org.apache.tapestry5.upload.services.UploadEvents;
025
026import 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")
033public 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    @Override
051    public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
052            throws IOException
053    {
054        FileUploadException uploadException = decoder.getUploadException();
055
056        if (uploadException != null)
057        {
058            Component page = componentSource.getPage(parameters.getActivePageName());
059
060            ComponentResultProcessorWrapper callback = new ComponentResultProcessorWrapper(resultProcessor);
061
062            page.getComponentResources().triggerEvent(UploadEvents.UPLOAD_EXCEPTION, new Object[] { uploadException },
063                                                      callback);
064
065            // If an event handler exists and returns a value, then the callback will be aborted and a response
066            // (typically a redirect) will already have been sent to the client.
067
068            if (callback.isAborted()) return;
069
070            // If the page does not properly handle the exception, then we throw it now.
071
072            throw new RuntimeException(UploadMessages.unableToDecode(), uploadException);
073        }
074
075
076        handler.handle(parameters);
077    }
078}