| /* |
| * 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.stanbol.enhancer.ldpath.function; |
| |
| import static org.apache.stanbol.enhancer.servicesapi.helper.ContentItemHelper.parseMimeType; |
| |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Map.Entry; |
| import java.util.Set; |
| |
| import org.apache.clerezza.rdf.core.LiteralFactory; |
| import org.apache.clerezza.commons.rdf.RDFTerm; |
| import org.apache.clerezza.commons.rdf.IRI; |
| import org.apache.commons.io.IOUtils; |
| import org.apache.marmotta.ldpath.api.backend.RDFBackend; |
| import org.apache.marmotta.ldpath.util.Collections; |
| import org.apache.stanbol.enhancer.ldpath.backend.ContentItemBackend; |
| import org.apache.stanbol.enhancer.servicesapi.Blob; |
| import org.apache.stanbol.enhancer.servicesapi.ContentItem; |
| import org.apache.stanbol.enhancer.servicesapi.helper.ContentItemHelper; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Provides access to the contents stored in {@link Blob}s added as content parts |
| * to a contentItem.<p> |
| * |
| * @author Rupert Westenthaler |
| * |
| */ |
| public class ContentFunction extends ContentItemFunction { |
| |
| Logger log = LoggerFactory.getLogger(ContentFunction.class); |
| LiteralFactory lf = LiteralFactory.getInstance(); |
| |
| public ContentFunction(){ |
| super("content"); |
| } |
| |
| @Override |
| public Collection<RDFTerm> apply(ContentItemBackend backend, RDFTerm context, Collection<RDFTerm>... args) throws IllegalArgumentException { |
| ContentItem ci = backend.getContentItem(); |
| Set<String> mimeTypes; |
| if(args == null || args.length < 1){ |
| mimeTypes = null; |
| } else { |
| mimeTypes = new HashSet<String>(); |
| for(Iterator<RDFTerm> params = Collections.concat(args).iterator();params.hasNext();){ |
| RDFTerm param = params.next(); |
| String mediaTypeString = backend.stringValue(param); |
| try { |
| mimeTypes.add(parseMimeType(mediaTypeString).get(null)); |
| } catch (IllegalArgumentException e) { |
| log.warn(String.format("Invalid mediaType '%s' (based on RFC 2046) parsed!", |
| mediaTypeString),e); |
| } |
| } |
| } |
| Collection<RDFTerm> result; |
| Blob blob; |
| if(mimeTypes == null || mimeTypes.isEmpty()){ |
| blob = ci.getBlob(); |
| } else { |
| Entry<IRI,Blob> entry = ContentItemHelper.getBlob(ci, mimeTypes); |
| blob = entry != null ? entry.getValue() : null; |
| } |
| if(blob == null){ |
| result = java.util.Collections.emptySet(); |
| } else { |
| String charset = blob.getParameter().get("charset"); |
| try { |
| if(charset != null){ |
| result = java.util.Collections.singleton( |
| backend.createLiteral(IOUtils.toString(blob.getStream(), charset))); |
| } else { //binary content |
| byte[] data = IOUtils.toByteArray(blob.getStream()); |
| result = java.util.Collections.singleton( |
| (RDFTerm)lf.createTypedLiteral(data)); |
| } |
| } catch (IOException e) { |
| throw new IllegalStateException("Unable to read contents from Blob '" |
| + blob.getMimeType()+"' of ContentItem "+ci.getUri(),e); |
| } |
| } |
| return result; |
| } |
| |
| @Override |
| public String getSignature() { |
| return "content = fn:content({content-resource},{media-type},{media-type2},.., {media-typeN})"; |
| } |
| |
| @Override |
| public String getDescription() { |
| return "Provides access to the Content stored in Blobs of the ContentItem"; |
| } |
| |
| } |