001/* 002 * Licensed to DuraSpace under one or more contributor license agreements. 003 * See the NOTICE file distributed with this work for additional information 004 * regarding copyright ownership. 005 * 006 * DuraSpace licenses this file to you under the Apache License, 007 * Version 2.0 (the "License"); you may not use this file except in 008 * compliance with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.fcrepo.http.api.responses; 019 020import static java.util.stream.Stream.of; 021import static javax.ws.rs.core.MediaType.APPLICATION_XHTML_XML; 022import static javax.ws.rs.core.MediaType.APPLICATION_XHTML_XML_TYPE; 023import static javax.ws.rs.core.MediaType.TEXT_HTML; 024import static javax.ws.rs.core.MediaType.TEXT_HTML_TYPE; 025import static com.google.common.collect.ImmutableMap.builder; 026import static org.apache.jena.graph.Node.ANY; 027import static org.apache.jena.sparql.util.graph.GraphUtils.multiValueURI; 028import static org.apache.jena.vocabulary.RDF.type; 029import static org.fcrepo.kernel.api.RdfLexicon.LDP_NAMESPACE; 030import static org.fcrepo.kernel.api.RdfLexicon.REPOSITORY_NAMESPACE; 031import static org.fcrepo.kernel.api.RdfCollectors.toModel; 032import static org.slf4j.LoggerFactory.getLogger; 033 034import java.io.IOException; 035import java.io.InputStream; 036import java.io.OutputStream; 037import java.io.OutputStreamWriter; 038import java.io.Writer; 039import java.lang.annotation.Annotation; 040import java.lang.reflect.Type; 041import java.net.URL; 042import java.util.Arrays; 043import java.util.List; 044import java.util.Map; 045import java.util.Properties; 046 047import javax.annotation.PostConstruct; 048import javax.ws.rs.Produces; 049import javax.ws.rs.core.MediaType; 050import javax.ws.rs.core.MultivaluedMap; 051import javax.ws.rs.core.UriInfo; 052import javax.ws.rs.ext.MessageBodyWriter; 053import javax.ws.rs.ext.Provider; 054 055import com.google.common.collect.ImmutableMap; 056import org.apache.jena.graph.Node; 057import org.apache.jena.rdf.model.Model; 058import org.apache.velocity.Template; 059import org.apache.velocity.VelocityContext; 060import org.apache.velocity.app.VelocityEngine; 061import org.apache.velocity.context.Context; 062import org.apache.velocity.tools.generic.EscapeTool; 063import org.apache.velocity.tools.generic.FieldTool; 064import org.fcrepo.http.commons.responses.HtmlTemplate; 065import org.fcrepo.http.commons.responses.RdfNamespacedStream; 066import org.fcrepo.http.commons.responses.ViewHelpers; 067import org.fcrepo.kernel.api.RdfLexicon; 068import org.slf4j.Logger; 069 070/** 071 * Simple HTML provider for RdfNamespacedStreams 072 * 073 * @author ajs6f 074 * @since Nov 19, 2013 075 */ 076@Provider 077@Produces({TEXT_HTML, APPLICATION_XHTML_XML}) 078public class StreamingBaseHtmlProvider implements MessageBodyWriter<RdfNamespacedStream> { 079 080 081 @javax.ws.rs.core.Context 082 UriInfo uriInfo; 083 084 private static EscapeTool escapeTool = new EscapeTool(); 085 086 protected VelocityEngine velocity = new VelocityEngine(); 087 088 /** 089 * Location in the classpath where Velocity templates are to be found. 090 */ 091 public static final String templatesLocation = "/views"; 092 093 /** 094 * Location in the classpath where the common css file is to be found. 095 */ 096 public static final String commonCssLocation = "/views/common.css"; 097 098 /** 099 * Location in the classpath where the common javascript file is to be found. 100 */ 101 public static final String commonJsLocation = "/views/common.js"; 102 103 /** 104 * A map from String names for primary node types to the Velocity templates 105 * that should be used for those node types. 106 */ 107 protected Map<String, Template> templatesMap; 108 109 public static final String templateFilenameExtension = ".vsl"; 110 111 public static final String velocityPropertiesLocation = 112 "/velocity.properties"; 113 114 private static final ViewHelpers VIEW_HELPERS = ViewHelpers.getInstance(); 115 116 private static final Logger LOGGER = 117 getLogger(StreamingBaseHtmlProvider.class); 118 119 @PostConstruct 120 void init() throws IOException { 121 122 LOGGER.trace("Velocity engine initializing..."); 123 final Properties properties = new Properties(); 124 final URL propertiesUrl = 125 getClass().getResource(velocityPropertiesLocation); 126 LOGGER.debug("Using Velocity configuration from {}", propertiesUrl); 127 try (final InputStream propertiesStream = propertiesUrl.openStream()) { 128 properties.load(propertiesStream); 129 } 130 velocity.init(properties); 131 LOGGER.trace("Velocity engine initialized."); 132 133 LOGGER.trace("Assembling a map of node primary types -> templates..."); 134 final ImmutableMap.Builder<String, Template> templatesMapBuilder = builder(); 135 136 of("fcr:versions", "fcr:fixity", "default") 137 .forEach(key -> templatesMapBuilder.put(key, velocity.getTemplate(getTemplateLocation(key)))); 138 139 templatesMap = templatesMapBuilder 140 .put(REPOSITORY_NAMESPACE + "RepositoryRoot", velocity.getTemplate(getTemplateLocation("root"))) 141 .put(REPOSITORY_NAMESPACE + "Binary", velocity.getTemplate(getTemplateLocation("binary"))) 142 .put(REPOSITORY_NAMESPACE + "Version", velocity.getTemplate(getTemplateLocation("resource"))) 143 .put(REPOSITORY_NAMESPACE + "Pairtree", velocity.getTemplate(getTemplateLocation("resource"))) 144 .put(REPOSITORY_NAMESPACE + "Container", velocity.getTemplate(getTemplateLocation("resource"))) 145 .put(LDP_NAMESPACE + "NonRdfSource", velocity.getTemplate(getTemplateLocation("binary"))) 146 .put(LDP_NAMESPACE + "RdfSource", velocity.getTemplate(getTemplateLocation("resource"))).build(); 147 148 LOGGER.trace("Assembled template map."); 149 LOGGER.trace("HtmlProvider initialization complete."); 150 } 151 152 @Override 153 public void writeTo(final RdfNamespacedStream nsStream, final Class<?> type, 154 final Type genericType, final Annotation[] annotations, 155 final MediaType mediaType, 156 final MultivaluedMap<String, Object> httpHeaders, 157 final OutputStream entityStream) throws IOException { 158 159 final Node subject = ViewHelpers.getContentNode(nsStream.stream.topic()); 160 161 final Model model = nsStream.stream.collect(toModel()); 162 model.setNsPrefixes(nsStream.namespaces); 163 164 final Template nodeTypeTemplate = getTemplate(model, subject, Arrays.asList(annotations)); 165 166 final Context context = getContext(model, subject); 167 168 // the contract of MessageBodyWriter<T> is _not_ to close the stream 169 // after writing to it 170 final Writer outWriter = new OutputStreamWriter(entityStream); 171 nodeTypeTemplate.merge(context, outWriter); 172 outWriter.flush(); 173 } 174 175 protected Context getContext(final Model model, final Node subject) { 176 final FieldTool fieldTool = new FieldTool(); 177 178 final Context context = new VelocityContext(); 179 context.put("rdfLexicon", fieldTool.in(RdfLexicon.class)); 180 context.put("helpers", VIEW_HELPERS); 181 context.put("esc", escapeTool); 182 context.put("rdf", model.getGraph()); 183 184 context.put("model", model); 185 context.put("subjects", model.listSubjects()); 186 context.put("nodeany", ANY); 187 context.put("topic", subject); 188 context.put("uriInfo", uriInfo); 189 return context; 190 } 191 192 private Template getTemplate(final Model rdf, final Node subject, 193 final List<Annotation> annotations) { 194 195 final String tplName = annotations.stream().filter(x -> x instanceof HtmlTemplate) 196 .map(x -> ((HtmlTemplate) x).value()).filter(templatesMap::containsKey).findFirst() 197 .orElseGet(() -> { 198 final List<String> types = multiValueURI(rdf.getResource(subject.getURI()), type); 199 if (types.contains(REPOSITORY_NAMESPACE + "RepositoryRoot")) { 200 return REPOSITORY_NAMESPACE + "RepositoryRoot"; 201 } 202 return types.stream().filter(templatesMap::containsKey).findFirst().orElse("default"); 203 }); 204 LOGGER.debug("Using template: {}", tplName); 205 return templatesMap.get(tplName); 206 } 207 208 @Override 209 public boolean isWriteable(final Class<?> type, final Type genericType, 210 final Annotation[] annotations, final MediaType mediaType) { 211 LOGGER.debug( 212 "Checking to see if type: {} is serializable to mimeType: {}", 213 type.getName(), mediaType); 214 return (mediaType.equals(TEXT_HTML_TYPE) || mediaType 215 .equals(APPLICATION_XHTML_XML_TYPE)) 216 && RdfNamespacedStream.class.isAssignableFrom(type); 217 } 218 219 @Override 220 public long getSize(final RdfNamespacedStream t, final Class<?> type, 221 final Type genericType, final Annotation[] annotations, 222 final MediaType mediaType) { 223 // we don't know in advance how large the result might be 224 return -1; 225 } 226 227 private static String getTemplateLocation(final String nodeTypeName) { 228 return templatesLocation + "/" + 229 nodeTypeName.replace(':', '-') + templateFilenameExtension; 230 } 231}