    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}