Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You 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.wicket.request.handler.resource; import org.apache.wicket.core.request.handler.logger.ResourceStreamLogData; import org.apache.wicket.request.ILoggableRequestHandler; import org.apache.wicket.request.IRequestCycle; import org.apache.wicket.request.IRequestHandler; import org.apache.wicket.request.resource.ContentDisposition; import org.apache.wicket.request.resource.IResource.Attributes; import org.apache.wicket.request.resource.ResourceStreamResource; import org.apache.wicket.util.lang.Args; import org.apache.wicket.util.resource.IResourceStream; import org.apache.wicket.util.string.Strings; import org.apache.wicket.util.time.Duration; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Request target that responds by sending its resource stream. * * @author Eelco Hillenius */ public class ResourceStreamRequestHandler implements IRequestHandler, ILoggableRequestHandler { /** Logger */ private static final Logger log = LoggerFactory.getLogger(ResourceStreamRequestHandler.class); /** * Optional filename, used to set the content disposition header. Only meaningful when using * with web requests. */ private String fileName; private ContentDisposition contentDisposition; /** * The duration fow which the resource will be cached by the browser. * <p> * By default is {@code null} and * {@link org.apache.wicket.settings.ResourceSettings#getDefaultCacheDuration()} is used. * </p> */ private Duration cacheDuration; /** the resource stream for the response. */ private final IResourceStream resourceStream; private ResourceStreamLogData logData; /** * Construct. * * @param resourceStream * the resource stream for the response */ public ResourceStreamRequestHandler(IResourceStream resourceStream) { this(resourceStream, null); } /** * Construct. * * @param resourceStream * the resource stream for the response * @param fileName */ public ResourceStreamRequestHandler(IResourceStream resourceStream, String fileName) { Args.notNull(resourceStream, "resourceStream"); this.resourceStream = resourceStream; this.fileName = fileName; } @Override public void detach(IRequestCycle requestCycle) { if (logData == null) logData = getResourceStream() == null ? new ResourceStreamLogData(this) : new ResourceStreamLogData(this, getResourceStream()); } /** {@inheritDoc} */ @Override public ResourceStreamLogData getLogData() { return logData; } /** * @return Optional filename, used to set the content disposition header. Only meaningful when * using with web requests. */ public final String getFileName() { return fileName; } /** * Gets the resource stream for the response. * * @return the resource stream for the response */ public final IResourceStream getResourceStream() { return resourceStream; } /** * Responds by sending the contents of the resource stream. * * @see org.apache.wicket.request.IRequestHandler#respond(org.apache.wicket.request.IRequestCycle) */ @Override public void respond(IRequestCycle requestCycle) { Attributes attributes = new Attributes(requestCycle.getRequest(), requestCycle.getResponse()); ResourceStreamResource resource = new ResourceStreamResource(resourceStream); configure(resource); resource.respond(attributes); } /** * Configures the ResourceStreamResource used by this request handler * * @param resource * the resource to configure */ protected void configure(ResourceStreamResource resource) { resource.setFileName(fileName); if (contentDisposition != null) { resource.setContentDisposition(contentDisposition); } else { resource.setContentDisposition( Strings.isEmpty(fileName) ? ContentDisposition.INLINE : ContentDisposition.ATTACHMENT); } final Duration cacheDuration = getCacheDuration(); if (cacheDuration != null) { resource.setCacheDuration(cacheDuration); } } @Override public int hashCode() { final int prime = 31; int result = 1; result = prime * result + ((contentDisposition == null) ? 0 : contentDisposition.hashCode()); result = prime * result + ((fileName == null) ? 0 : fileName.hashCode()); result = prime * result + resourceStream.hashCode(); return result; } @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (getClass() != obj.getClass()) return false; ResourceStreamRequestHandler other = (ResourceStreamRequestHandler) obj; if (contentDisposition != other.contentDisposition) return false; if (fileName == null) { if (other.fileName != null) return false; } else if (!fileName.equals(other.fileName)) return false; if (!resourceStream.equals(other.resourceStream)) return false; return true; } /** * @param fileName * Optional filename, used to set the content disposition header. Only meaningful * when using with web requests. * * @return The this. */ public final ResourceStreamRequestHandler setFileName(String fileName) { this.fileName = fileName; return this; } /** * @see java.lang.Object#toString() */ @Override public String toString() { return "[ResourceStreamRequestTarget[resourceStream=" + resourceStream + ",fileName=" + fileName + ", contentDisposition=" + contentDisposition + "]"; } /** * @return ContentDisposition */ public final ContentDisposition getContentDisposition() { return contentDisposition; } /** * @param contentDisposition * @return this */ public final ResourceStreamRequestHandler setContentDisposition(ContentDisposition contentDisposition) { this.contentDisposition = contentDisposition; return this; } /** * @return the duration for which the resource will be cached by the browser */ public Duration getCacheDuration() { return cacheDuration; } /** * @param cacheDuration * the duration for which the resource will be cached by the browser * @return this component */ public ResourceStreamRequestHandler setCacheDuration(Duration cacheDuration) { this.cacheDuration = cacheDuration; return this; } }