    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.beanmodel.services.*;
    020import org.apache.tapestry5.internal.services.ComponentResultProcessorWrapper;
    021import org.apache.tapestry5.ioc.annotations.Primary;
    022import org.apache.tapestry5.runtime.Component;
    023import org.apache.tapestry5.services.ComponentEventRequestFilter;
    024import org.apache.tapestry5.services.ComponentEventRequestHandler;
    025import org.apache.tapestry5.services.ComponentEventRequestParameters;
    026import org.apache.tapestry5.services.ComponentEventResultProcessor;
    027import org.apache.tapestry5.services.ComponentSource;
    028import org.apache.tapestry5.services.Traditional;
    029import org.apache.tapestry5.upload.services.MultipartDecoder;
    030import org.apache.tapestry5.upload.services.UploadEvents;
    031
    032import java.io.IOException;
    033
    034/**
    035 * Determines if there was an {@link org.apache.commons.fileupload.FileUploadException} processing the request and, if
    036 * so, triggers an exception event on the page. If the page fails to respond to the event, then
    037 */
    038@Events(UploadEvents.UPLOAD_EXCEPTION + " when a exception occur processing the upload")
    039public class UploadExceptionFilter implements ComponentEventRequestFilter
    040{
    041    private final MultipartDecoder decoder;
    042
    043    private final ComponentEventResultProcessor resultProcessor;
    044
    045    private ComponentSource componentSource;
    046
    047    public UploadExceptionFilter(MultipartDecoder decoder,
    048                                 @Traditional @Primary ComponentEventResultProcessor resultProcessor,
    049                                 ComponentSource componentSource)
    050    {
    051        this.decoder = decoder;
    052        this.resultProcessor = resultProcessor;
    053        this.componentSource = componentSource;
    054    }
    055
    056    @Override
    057    public void handle(ComponentEventRequestParameters parameters, ComponentEventRequestHandler handler)
    058            throws IOException
    059    {
    060        FileUploadException uploadException = decoder.getUploadException();
    061
    062        if (uploadException != null)
    063        {
    064            Component page = componentSource.getPage(parameters.getActivePageName());
    065
    066            ComponentResultProcessorWrapper callback = new ComponentResultProcessorWrapper(resultProcessor);
    067
    068            page.getComponentResources().triggerEvent(UploadEvents.UPLOAD_EXCEPTION, new Object[] { uploadException },
    069                                                      callback);
    070
    071            // If an event handler exists and returns a value, then the callback will be aborted and a response
    072            // (typically a redirect) will already have been sent to the client.
    073
    074            if (callback.isAborted()) return;
    075
    076            // If the page does not properly handle the exception, then we throw it now.
    077
    078            throw new RuntimeException(UploadMessages.unableToDecode(), uploadException);
    079        }
    080
    081
    082        handler.handle(parameters);
    083    }
    084}