source: gs3-extensions/iiif-servlet/trunk/src/gsdl-src/java/org/greenstone/gsdl3/core/IIIFReceptionist.java@ 32842

Last change on this file since 32842 was 32842, checked in by davidb, 5 years ago

Shift from OAI as a template, to separate IIIF based classes
File size: 16.2 KB
Line 
1/*
2 * IIIFReceptionist.java
3 * Copyright (C) 2018 New Zealand Digital Library, http://www.nzdl.org
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19
20package org.greenstone.gsdl3.core;
21
22import org.greenstone.gsdl3.util.*;
23import org.greenstone.gsdl3.action.*;
24// XML classes
25import org.w3c.dom.Node;
26import org.w3c.dom.NodeList;
27import org.w3c.dom.Document;
28import org.w3c.dom.Element;
29
30// other java classes
31import java.io.File;
32import java.util.*;
33
34import org.apache.log4j.*;
35
36/** a Receptionist, used for IIIF image server support.
37 * This receptionist talks to the message router directly,
38 * instead of via any action, hence no action map is needed.
39 * @see the basic Receptionist
40 */
41public class IIIFReceptionist implements ModuleInterface {
42
43 static Logger logger = Logger.getLogger(org.greenstone.gsdl3.core.IIIFReceptionist.class.getName());
44
45 /** Instead of a config_params object, only a site_name is needed by iiif receptionist. */
46 protected String site_name = null;
47 /** The unique repository identifier */
48 /*
49 protected String repository_id = null;
50 */
51
52 /** the configure file of this receptionist passed from the iiif restlet. */
53 protected Element iiif_config = null;
54
55 /** the message router that the Receptionist and Actions will talk to */
56 protected ModuleInterface mr = null;
57
58 // Some of the data/responses will not change while the servlet is running, so
59 // we can cache them
60
61 /** A list of all the collections available to this IIIF image server */
62 protected Element collection_list = null;
63 /** a vector of the names, for convenience */
64 protected Vector<String> collection_name_list = null;
65 /** If this is true, then there are no OAI enabled collections, so can always return
66 noRecordsMatch (after validating the request params) */
67 protected boolean noRecordsMatch = false;
68
69 /** A set of all known 'sets' */
70 protected HashSet<String> set_set = null;
71
72 protected boolean has_super_colls = false;
73 /** a hash of super set-> collection list */
74 protected HashMap<String, Vector<String>> super_coll_map = null;
75 /** store the super coll elements for convenience */
76 HashMap<String, Element> super_coll_data = null;
77 /** store the metadata formats ??????*/
78 /** The identify response */
79 protected Element identify_response = null;
80 /** The list set response */
81 protected Element listsets_response = null;
82 /** the list metadata formats response */
83 protected Element listmetadataformats_response = null;
84
85 public IIIFReceptionist() {
86
87 }
88
89 public void cleanUp() {
90 if (this.mr != null) {
91
92 this.mr.cleanUp();
93 }
94 }
95
96 public void setSiteName(String site_name) {
97 this.site_name = site_name;
98 }
99 /** sets the message router - it should already be created and
100 * configured in the init() of a servlet/restlet (IIIFServerBridge, for example) before being passed to the receptionist*/
101 public void setMessageRouter(ModuleInterface mr) {
102 this.mr = mr;
103 }
104
105 /** configures the receptionist */
106 public boolean configure(Element config) {
107
108 if (this.mr==null) {
109 logger.error(" message routers must be set before calling IIIF configure");
110 return false;
111 }
112 if (config == null) {
113 logger.error(" IIIF configure file is null");
114 return false;
115 }
116 iiif_config = config;
117
118 /*
119 repository_id = getRepositoryIdentifier();
120 */
121
122 /*
123 if (!configureSetInfo()) {
124 // there are no sets
125 logger.error("No sets (collections) available for IIIF");
126 return false;
127 }
128 */
129
130 return true;
131 }
132
133 /*
134 private boolean configureSetInfo() {
135 this.set_set = new HashSet<String>();
136
137 // First, we get a list of all the OAI enabled collections
138 // We get this by sending a listSets request to the MR
139 Document doc = XMLConverter.newDOM();
140 Element message = doc.createElement(GSXML.MESSAGE_ELEM);
141
142 Element request = GSXML.createBasicRequest(doc, OAIXML.OAI_SET_LIST, "", null);
143 message.appendChild(request);
144 Node msg_node = mr.process(message);
145
146 if (msg_node == null) {
147 logger.error("returned msg_node from mr is null");
148 return false;
149 }
150 Element resp = (Element)GSXML.getChildByTagName(msg_node, GSXML.RESPONSE_ELEM);
151 Element coll_list = (Element)GSXML.getChildByTagName(resp, GSXML.COLLECTION_ELEM + GSXML.LIST_MODIFIER);
152 if (coll_list == null) {
153 logger.error("coll_list is null");
154 return false;
155 }
156
157 this.collection_list = (Element)doc.importNode(coll_list, true);
158
159 // go through and store a list of collection names for convenience
160 // also create a 'to' attribute for the next request to the MR, which
161 // is a ListSets request to each collection
162 Node child = this.collection_list.getFirstChild();
163 if (child == null) {
164 logger.error("collection list has no children");
165 noRecordsMatch = true;
166 return false;
167 }
168
169 this.collection_name_list = new Vector<String>();
170 StringBuffer to = new StringBuffer();
171 boolean first = true;
172 while (child != null) {
173 if (child.getNodeName().equals(GSXML.COLLECTION_ELEM)) {
174 String coll_id =((Element) child).getAttribute(GSXML.NAME_ATT);
175 this.collection_name_list.add(coll_id);
176 if (!first) {
177 to.append(',');
178 }
179 first = false;
180 to.append(coll_id+"/"+OAIXML.LIST_SETS);
181 }
182 child = child.getNextSibling();
183 }
184 if (first) {
185 // we haven't found any collections
186 logger.error("found no collection elements in collectionList");
187 noRecordsMatch = true;
188 return false;
189 }
190 Document listsets_doc = XMLConverter.newDOM();
191 Element listsets_element = listsets_doc.createElement(OAIXML.LIST_SETS);
192 this.listsets_response = getMessage(listsets_doc, listsets_element);
193
194 // Now, for each collection, get a list of all its sets
195 // might include subsets (classifiers) or super colls
196 // We'll reuse the first message, changing its type and to atts
197 request.setAttribute(GSXML.TYPE_ATT, "");
198 request.setAttribute(GSXML.TO_ATT, to.toString());
199 // send to MR
200 msg_node = mr.process(message);
201 //logger.info("*** " + XMLConverter.getPrettyString(msg_node));
202 NodeList response_list = ((Element)msg_node).getElementsByTagName(GSXML.RESPONSE_ELEM);
203 for (int c=0; c<response_list.getLength(); c++) {
204 // for each collection's response
205 Element response = (Element)response_list.item(c);
206 String coll_name = GSPath.getFirstLink(response.getAttribute(GSXML.FROM_ATT));
207 logger.info("*** coll from response "+coll_name);
208 NodeList set_list = response.getElementsByTagName(OAIXML.SET);
209 for (int j=0; j<set_list.getLength(); j++) {
210 // now check if it a super collection
211 Element set = (Element)set_list.item(j);
212 String set_spec = GSXML.getNodeText((Element)GSXML.getChildByTagName(set, OAIXML.SET_SPEC));
213 logger.info("*** set spec = "+set_spec);
214 // this may change if we add site name back in
215 // setSpecs will be collname or collname:subset or supercollname
216 if (set_spec.indexOf(":")==-1 && ! set_spec.equals(coll_name)) {
217 // it must be a super coll spec
218 logger.info("*** found super coll, "+set_spec);
219 // check that it is a valid one from config
220 if (this.has_super_colls == true && this.super_coll_data.containsKey(set_spec)) {
221 Vector <String> subcolls = this.super_coll_map.get(set_spec);
222 if (subcolls == null) {
223 logger.info("*** its new!!");
224 // not in there yet
225 subcolls = new Vector<String>();
226 this.set_set.add(set_spec);
227 this.super_coll_map.put(set_spec, subcolls);
228 // the first time a supercoll is mentioned, add into the set list
229 logger.info("*** finding the set info "+XMLConverter.getPrettyString(this.super_coll_data.get(set_spec)));
230 listsets_element.appendChild(GSXML.duplicateWithNewName(listsets_doc, this.super_coll_data.get(set_spec), OAIXML.SET, true));
231 }
232 // add this collection to the list for the super coll
233 subcolls.add(coll_name);
234 }
235 } else { // its either the coll itself or a subcoll
236 // add in the set
237 listsets_element.appendChild(listsets_doc.importNode(set, true));
238 this.set_set.add(set_spec);
239 }
240 } // for each set in the collection
241 } // for each OAI enabled collection
242 return true;
243 }
244 */
245
246 protected void resetMessageRouter() {
247 // we just need to send a configure request to MR
248 Document doc = XMLConverter.newDOM();
249 Element mr_request_message = doc.createElement(GSXML.MESSAGE_ELEM);
250 Element mr_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_SYSTEM, "", null);
251 mr_request_message.appendChild(mr_request);
252
253 Element system = doc.createElement(GSXML.SYSTEM_ELEM);
254 mr_request.appendChild(system);
255 system.setAttribute(GSXML.TYPE_ATT, GSXML.SYSTEM_TYPE_CONFIGURE);
256
257 Element response = (Element) this.mr.process(mr_request_message);
258 logger.info("*** configure response = "+XMLConverter.getPrettyString(response));
259 }
260
261 /** process using strings - just calls process using Elements */
262 public String process(String xml_in) {
263
264 Node message_node = XMLConverter.getDOM(xml_in);
265 Node page = process(message_node);
266 return XMLConverter.getString(page);
267 }
268
269 //Compose a message/response element used to send back to the IIIFServerBridge servlet.
270 //This method is only used within IIIFReceptionist
271 private Element getMessage(Document doc, Element e) {
272 Element msg = doc.createElement(GSXML.MESSAGE_ELEM);
273 Element response = doc.createElement(GSXML.RESPONSE_ELEM);
274 msg.appendChild(response);
275 response.appendChild(e);
276 return msg;
277 }
278
279 /** process - produce xml data in response to a request
280 * if something goes wrong, it returns null -
281 */
282 public Node process(Node message_node) {
283 logger.info("*** IIIFReceptionist received request");
284
285 Element message = GSXML.nodeToElement(message_node);
286 logger.info("*** " + XMLConverter.getString(message));
287
288 // check that its a correct message tag
289 if (!message.getTagName().equals(GSXML.MESSAGE_ELEM)) {
290 logger.error(" Invalid message. GSDL message should start with <"+GSXML.MESSAGE_ELEM+">, instead it starts with:"+message.getTagName()+".");
291 return IIIFXML.createErrorMessage(OAIXML.BAD_ARGUMENT, "Internal messaging error");
292 }
293
294 // get the request out of the message - assume that there is only one
295 Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
296 if (request == null) {
297 logger.error(" message had no request!");
298 return IIIFXML.createErrorMessage(OAIXML.BAD_ARGUMENT, "Internal messaging error");
299 }
300
301 // special case, reset=true for reloading the MR and recept data
302 String reset = request.getAttribute("reset");
303 if (!reset.equals("")) {
304 resetMessageRouter();
305 // configureSetInfo(); // ****
306 return IIIFXML.createResetResponse(true);
307 }
308
309
310 //At this stage, the value of 'to' attribute of the request must be the 'verb'
311 //The only thing that the oai receptionist can be sure is that these verbs are valid, nothing else.
312 String verb = request.getAttribute(GSXML.TO_ATT);
313 /*
314 if (verb.equals(OAIXML.IDENTIFY)) {
315 return doIdentify();
316 }*/
317
318 if (verb.equals(OAIXML.GET_RECORD)) {
319 return doGetRecord(request);
320 }
321
322 // should never get here as verbs were checked in IIIFServerBridge
323 return IIIFXML.createErrorMessage(OAIXML.BAD_VERB, "Unexpected things happened");
324
325 }
326
327 /*
328 private String getRepositoryIdentifier() {
329 Element ri = (Element)GSXML.getChildByTagName(iiif_config, OAIXML.REPOSITORY_IDENTIFIER);
330 if (ri != null) {
331 return GSXML.getNodeText(ri);
332 }
333 return "";
334 }
335 */
336
337 private void copyNamedElementfromConfig(Element to_elem, String element_name) {
338 Element original_element = (Element)GSXML.getChildByTagName(iiif_config, element_name);
339 if(original_element != null) {
340 GSXML.copyNode(to_elem, original_element);
341 }
342 }
343
344 /*
345 private Element doIdentify() {
346 //The validation for this verb has been done in OAIServer.validate(). So no bother here.
347 logger.info("");
348 if (this.identify_response != null) {
349 // we have already created it
350 return getMessage(this.identify_response.getOwnerDocument(), this.identify_response);
351 }
352 Document doc = XMLConverter.newDOM();
353 Element identify = doc.createElement(OAIXML.IDENTIFY);
354 //do the repository name
355 copyNamedElementfromConfig(identify, OAIXML.REPOSITORY_NAME);
356 //do the baseurl
357 copyNamedElementfromConfig(identify, OAIXML.BASE_URL);
358 //do the protocol version
359 copyNamedElementfromConfig(identify, OAIXML.PROTOCOL_VERSION);
360
361 //There can be more than one admin email according to the OAI specification
362 NodeList admin_emails = GSXML.getChildrenByTagName(iiif_config, OAIXML.ADMIN_EMAIL);
363 int num_admin = 0;
364 Element from_admin_email = null;
365 if (admin_emails != null) {
366 num_admin = admin_emails.getLength();
367 }
368 for (int i=0; i<num_admin; i++) {
369 GSXML.copyNode(identify, admin_emails.item(i));
370 }
371
372 // IIIF does not have the equivalent of oai earliestDatestamp
373
374 // output the oai identifier
375 Element description = doc.createElement(OAIXML.DESCRIPTION);
376 identify.appendChild(description);
377 // TODO, make this a valid id
378 Element oaiIdentifier = OAIXML.createOAIIdentifierXML(doc, repository_id, "lucene-jdbm-demo", "ec159e");
379 description.appendChild(oaiIdentifier);
380
381 // if there are any oaiInfo metadata, add them in too.
382 Element info = (Element)GSXML.getChildByTagName(iiif_config, OAIXML.OAI_INFO);
383 if (info != null) {
384 NodeList meta = GSXML.getChildrenByTagName(info, OAIXML.METADATA);
385 if (meta != null && meta.getLength() > 0) {
386 Element gsdl = OAIXML.createGSDLElement(doc);
387 description.appendChild(gsdl);
388 for (int m = 0; m<meta.getLength(); m++) {
389 GSXML.copyNode(gsdl, meta.item(m));
390 }
391
392 }
393 }
394 this.identify_response = identify;
395 return getMessage(doc, identify);
396 }
397 */
398
399 private Element doGetRecord(Element req){
400 logger.info("");
401 /** arguments:
402 identifier: required
403 metadataPrefix: required
404 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
405 */
406 Document doc = XMLConverter.newDOM();
407 Element get_record = doc.createElement(IIIFXML.GET_RECORD);
408
409 HashSet<String> valid_strs = new HashSet<String>();
410 valid_strs.add(OAIXML.IDENTIFIER);
411 valid_strs.add(OAIXML.METADATA_PREFIX);
412
413 NodeList params = GSXML.getChildrenByTagName(req, GSXML.PARAM_ELEM);
414 HashMap<String, String> param_map = GSXML.getParamMap(params);
415
416 // Any need to check all params are valid, like OAI??
417
418 String identifier = param_map.get(OAIXML.IDENTIFIER);
419
420 // get the names
421 String[] strs = identifier.split(":", 2);
422 if(strs == null || strs.length < 2) {
423 logger.error("identifier is not in the form coll:id" + identifier);
424 return OAIXML.createErrorMessage(OAIXML.ID_DOES_NOT_EXIST, "");
425 }
426 //String name_of_site = strs[0];
427 String coll_name = strs[0];
428 String oid = strs[1];
429
430 //re-organize the request element
431 // reset the 'to' attribute
432 String verb = req.getAttribute(GSXML.TO_ATT);
433 req.setAttribute(GSXML.TO_ATT, coll_name + "/" + verb);
434 // reset the identifier element
435 Element param = GSXML.getNamedElement(req, GSXML.PARAM_ELEM, GSXML.NAME_ATT, OAIXML.IDENTIFIER);
436 if (param != null) {
437 param.setAttribute(GSXML.NAME_ATT, OAIXML.OID);
438 param.setAttribute(GSXML.VALUE_ATT, oid);
439 }
440
441 //Now send the request to the message router to process
442 Element msg = doc.createElement(GSXML.MESSAGE_ELEM);
443 msg.appendChild(doc.importNode(req, true));
444 Node result_node = mr.process(msg);
445 return GSXML.nodeToElement(result_node);
446 }
447
448
449}
450
451
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