source: greenstone3/trunk/src/java/org/greenstone/gsdl3/service/OAIPMH.java@ 16871

Last change on this file since 16871 was 16871, checked in by kjdon, 16 years ago

added type=oai to all oai service elements
File size: 28.7 KB
Line 
1/*
2 * OAIPMH.java
3 * Copyright (C) 2002 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 */
19package org.greenstone.gsdl3.service;
20
21// Greenstone classes
22import org.greenstone.gsdl3.core.GSException;
23import org.greenstone.gsdl3.util.GSXML;
24import org.greenstone.gsdl3.util.OAIXML;
25import org.greenstone.gsdl3.util.OID;
26import org.greenstone.gsdl3.util.GSFile;
27import org.greenstone.gsdl3.util.XMLConverter;
28
29import org.greenstone.gsdl3.util.SimpleCollectionDatabase;
30import org.greenstone.gsdl3.util.DBInfo;
31// XML classes
32import org.w3c.dom.Document;
33import org.w3c.dom.Element;
34import org.w3c.dom.NodeList;
35
36// General Java classes
37import java.io.File;
38import java.util.StringTokenizer;
39import java.util.Vector;
40import java.util.Set;
41import java.util.Iterator;
42import java.util.ArrayList;
43import java.util.Date;
44import java.util.HashMap;
45import java.util.Map.Entry;
46
47import org.apache.log4j.Logger;
48
49/** Implements the oai metadata retrieval service for GS3 collections.
50 * Dig into each collection's database and retrieve the metadata
51 *
52 * @author <a href="mailto:[email protected]">Xiao</a>
53 */
54
55public class OAIPMH extends ServiceRack {
56
57 static Logger logger = Logger.getLogger(org.greenstone.gsdl3.service.OAIPMH.class.getName());
58
59 protected SimpleCollectionDatabase coll_db = null;
60
61 protected String site_name = "";
62 protected String coll_name = "";
63 protected Element coll_config_xml = null;
64
65 /** constructor */
66 public OAIPMH() {
67
68 }
69
70 public void cleanUp() {
71 super.cleanUp();//??
72 this.coll_db.closeDatabase();
73 }
74 /** configure this service */
75 public boolean configure(Element info, Element extra_info) {
76 if (!super.configure(info, extra_info)){
77 logger.info("Configuring ServiceRack.java returns false.");
78 return false;
79 }
80
81 //get the names from ServiceRack.java
82 site_name = this.router.getSiteName();
83 coll_name = this.cluster_name;
84 //get the collection-specific configurations from collectionConfig.xml
85 coll_config_xml = OAIXML.getCollectionConfigXML(site_name, coll_name);
86
87 logger.info("Configuring OAIPMH...");
88 // this call passes the indexStem in of ServiceRack element in buildConfig.xml to the super class.
89 this.config_info = info;
90
91 // the index stem is either specified in the buildConfig.xml file or uses the collection name
92 Element index_stem_elem = (Element) GSXML.getChildByTagName(info, GSXML.INDEX_STEM_ELEM);
93 String index_stem = null;
94 if (index_stem_elem != null) {
95 index_stem = index_stem_elem.getAttribute(GSXML.NAME_ATT);
96 }
97 if (index_stem == null || index_stem.equals("")) {
98 index_stem = this.cluster_name;
99 }
100
101 // find out what kind of database we have
102 Element database_type_elem = (Element) GSXML.getChildByTagName(info, GSXML.DATABASE_TYPE_ELEM);
103 String database_type = null;
104 if (database_type_elem != null) {
105 database_type = database_type_elem.getAttribute(GSXML.NAME_ATT);
106 }
107 if (database_type == null || database_type.equals("")) {
108 database_type = "gdbm"; // the default
109 }
110 coll_db = new SimpleCollectionDatabase(database_type);
111 if (coll_db == null) {
112 logger.error("Couldn't create the collection database of type "+database_type);
113 return false;
114 }
115
116 // Open database for querying
117 String coll_db_file = GSFile.collectionDatabaseFile(this.site_home, this.cluster_name, index_stem, database_type);
118 if (!this.coll_db.openDatabase(coll_db_file, SimpleCollectionDatabase.READ)) {
119 logger.error("Could not open collection database!");
120 return false;
121 }
122
123 // the short_service_info is used by the message router to find the method names,
124 //so we just use the doc variable in class ServiceRack to create the xml; but
125 // in each method we will use OAIXML to create the response xml
126 // set up short_service_info_ - just the name
127
128 Element identify = this.doc.createElement(OAIXML.SERVICE);
129
130 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
131 identify.setAttribute(GSXML.TYPE_ATT, "oai");
132 this.short_service_info.appendChild(identify);
133
134 Element list_records = this.doc.createElement(OAIXML.SERVICE);
135 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
136 list_records.setAttribute(GSXML.TYPE_ATT, "oai");
137 this.short_service_info.appendChild(list_records);
138
139 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
140 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
141 list_identifiers.setAttribute(GSXML.TYPE_ATT, "oai");
142 this.short_service_info.appendChild(list_identifiers);
143
144 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
145 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
146 list_sets.setAttribute(GSXML.TYPE_ATT, "oai");
147 this.short_service_info.appendChild(list_sets);
148
149 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
150 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
151 list_metadata_formats.setAttribute(GSXML.TYPE_ATT, "oai");
152 this.short_service_info.appendChild(list_metadata_formats);
153
154 Element get_record = this.doc.createElement(OAIXML.SERVICE);
155 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
156 get_record.setAttribute(GSXML.TYPE_ATT, "oai");
157 this.short_service_info.appendChild(get_record);
158
159 return true;
160 }
161 /** returns a specific service description */
162 public Element getServiceDescription(String service_id, String lang, String subset) {
163
164 if (service_id.equals(OAIXML.IDENTIFY)) {
165 Element identify = this.doc.createElement(OAIXML.SERVICE);
166 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
167 identify.setAttribute(GSXML.TYPE_ATT, "oai");
168 return identify;
169 }
170 if (service_id.equals(OAIXML.LIST_RECORDS)) {
171 Element list_records = this.doc.createElement(OAIXML.SERVICE);
172 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
173 list_records.setAttribute(GSXML.TYPE_ATT, "oai");
174 return list_records;
175 }
176
177 if (service_id.equals(OAIXML.LIST_IDENTIFIERS)) {
178 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
179 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
180 list_identifiers.setAttribute(GSXML.TYPE_ATT, "oai");
181 return list_identifiers;
182 }
183 if (service_id.equals(OAIXML.LIST_SETS)) {
184 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
185 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
186 list_sets.setAttribute(GSXML.TYPE_ATT, "oai");
187 return list_sets;
188 }
189 if (service_id.equals(OAIXML.LIST_METADATA_FORMATS)) {
190 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
191 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
192 list_metadata_formats.setAttribute(GSXML.TYPE_ATT, "oai");
193 return list_metadata_formats;
194 }
195
196 if (service_id.equals(OAIXML.GET_RECORD)) {
197 Element get_record = this.doc.createElement(OAIXML.SERVICE);
198 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
199 get_record.setAttribute(GSXML.TYPE_ATT, "oai");
200 return get_record;
201 }
202
203 return null;
204 }
205 /** return the metadata information about this set of the repository */
206 protected Element processIdentify(Element req) {
207 return null;
208 }
209 /** return the metadata information */
210 protected Element processListSets(Element req) {
211 //This method is never called unless each set in the returned message contain a
212 //'description' element so that we need to ask each collection for their info
213 return null;
214 }
215 /** return the metadata information */
216 protected Element processGetRecord(Element req) {
217 /** arguments:
218 identifier: required
219 metadataPrefix: required
220 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
221 */
222 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
223 HashMap param_map = OAIXML.getParamMap(params);
224
225 String prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
226 if (prefix == null || prefix.equals("")) {
227 //Just a double-check
228 logger.error("the value of metadataPrefix att is not present in the request.");
229 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
230 }
231
232 Element metadata_format = getMetadataFormatElement(prefix);
233 if(metadata_format == null) {
234 logger.error("metadata prefix is not supported.");
235 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
236 }
237
238 String oid = (String)param_map.get(OAIXML.OID);
239
240 //get a DBInfo object of the identifier; if this identifier is not present in the database,
241 // null is returned.
242 DBInfo info = this.coll_db.getInfo(oid);
243 if (info == null) {
244 logger.error("OID: " + oid + " is not present in the database.");
245 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
246 }
247
248 ArrayList keys = new ArrayList(info.getKeys());
249 String lastmodified = "";
250 if(keys.contains(OAIXML.LASTMODIFIED)) {
251 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
252 }
253 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
254
255 Element get_record = OAIXML.createElement(OAIXML.GET_RECORD);
256 Element record = OAIXML.createElement(OAIXML.RECORD);
257 //compose the header element
258 record.appendChild(createHeaderElement(oid, lastmodified));
259 //compose the metadata element
260 record.appendChild(createMetadataElement(prefix, info, metadata_format));
261 get_record.appendChild(record);
262 return OAIXML.getResponse(get_record);
263 }
264 /** return a list of identifiers */
265 protected Element processListIdentifiers(Element req) {
266 /** arguments:
267 metadataPrefix: required
268 * from: optional
269 * until: optional
270 * set: optional
271 * resumptionToken: exclusive and optional (ignored as it has been handled by OAIReceptionist)
272 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
273 */
274 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
275
276 if(params.getLength() == 0) {
277 logger.error("must at least have the metadataPrefix parameter, can't be none");
278 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
279 }
280
281 HashMap param_map = OAIXML.getParamMap(params);
282
283 String prefix = "";
284 Date from_date = null;
285 Date until_date = null;
286
287 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
288 //Just a double-check
289 logger.error("A param element containing the metadataPrefix is not present.");
290 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
291 }
292 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
293 if (prefix == null || prefix.equals("")) {
294 //Just a double-check
295 logger.error("the value of metadataPrefix att is not present in the request.");
296 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
297 }
298
299 if(param_map.containsKey(OAIXML.FROM)) {
300 String from = (String)param_map.get(OAIXML.FROM);
301 from_date = OAIXML.getDate(from);
302 }
303 if(param_map.containsKey(OAIXML.UNTIL)) {
304 String until = (String)param_map.get(OAIXML.UNTIL);
305 until_date = OAIXML.getDate(until);
306 }
307
308 Element metadata_format = getMetadataFormatElement(prefix);
309 if(metadata_format == null) {
310 logger.error("metadata prefix is not supported.");
311 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
312 }
313 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
314 if (oid_list == null) {
315 logger.error("No matched records found in collection: browselist is empty");
316 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
317 }
318 // all validation is done
319 Element list_identifiers = OAIXML.createElement(OAIXML.LIST_IDENTIFIERS);
320 for(int i=0; i<oid_list.size(); i++) {
321 String oid = (String)oid_list.get(i);
322 DBInfo info = this.coll_db.getInfo(oid);
323 if (info == null) {
324 logger.error("Database does not contains information about oid: " +oid);
325 continue;
326 }
327 ArrayList keys = new ArrayList(info.getKeys());
328 String lastmodified = "";
329 if(keys.contains(OAIXML.LASTMODIFIED)) {
330 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
331 }
332 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
333
334 Date this_date = OAIXML.getDate(lastmodified);
335 if (from_date != null) {
336 if(this_date.before(from_date)) {
337 continue;
338 }
339 }
340 if (until_date != null) {
341 if (this_date.after(until_date)) {
342 continue;
343 }
344 }
345 //compose the header element and append it
346 list_identifiers.appendChild(createHeaderElement(oid, lastmodified));
347 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
348
349 return OAIXML.getResponse(list_identifiers);
350 }
351 /** return a list of records */
352 protected Element processListRecords(Element req) {
353 /** the request sent here may contain optional 'from', 'untill', 'metadataPrefix',
354 * and 'resumptionToken' params. see doListSets() in OAIReceptionist.
355 * if the request contains 'resumptionToken' then it should have been handled by the
356 * OAIReceptionist. Therefore, the request sent here must not contain 'resumptionToken'
357 * argument but a 'metadataPrefix' param. The OAIReceptionist makes sure of this.
358 */
359 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
360
361 if(params.getLength() == 0) {
362 logger.error("must at least have the metadataPrefix parameter, can't be none");
363 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
364 }
365
366 HashMap param_map = OAIXML.getParamMap(params);
367
368 String prefix = "";
369 Date from_date = null;
370 Date until_date = null;
371
372 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
373 //Just a double-check
374 logger.error("A param element containing the metadataPrefix is not present.");
375 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
376 }
377 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
378 if (prefix == null || prefix.equals("")) {
379 //Just a double-check
380 logger.error("the value of metadataPrefix att is not present in the request.");
381 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
382 }
383
384 if(param_map.containsKey(OAIXML.FROM)) {
385 String from = (String)param_map.get(OAIXML.FROM);
386 from_date = OAIXML.getDate(from);
387 }
388 if(param_map.containsKey(OAIXML.UNTIL)) {
389 String until = (String)param_map.get(OAIXML.UNTIL);
390 until_date = OAIXML.getDate(until);
391 }
392 Element metadata_format = getMetadataFormatElement(prefix);
393 if(metadata_format == null) {
394 logger.error("metadata prefix is not supported.");
395 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
396 }
397// Another way of doing the same job!
398// HashMap prefix_map = OAIXML.getChildrenMapByTagName(coll_config_xml, OAIXML.METADATA_PREFIX);
399// if(!prefix_map.contains(prefix)) {
400// logger.error("metadata prefix is not supported.");
401// return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
402// }
403
404 //get a list of identifiers (it contains a list of strings)
405 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
406 if (oid_list == null) {
407 logger.error("No matched records found in collection: browselist is empty");
408 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
409 }
410 // all validation is done
411 Element list_records = OAIXML.createElement(OAIXML.LIST_RECORDS);
412 for(int i=0; i<oid_list.size(); i++) {
413 String oid = (String)oid_list.get(i);
414 DBInfo info = this.coll_db.getInfo(oid);
415 if (info == null) {
416 logger.error("Database does not contains information about oid: " +oid);
417 continue;
418 }
419 ArrayList keys = new ArrayList(info.getKeys());
420 String lastmodified = "";
421 if(keys.contains(OAIXML.LASTMODIFIED)) {
422 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
423 }
424 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
425
426 Date this_date = OAIXML.getDate(lastmodified);
427 if (from_date != null) {
428 if(this_date.before(from_date)) {
429 continue;
430 }
431 }
432 if (until_date != null) {
433 if (this_date.after(until_date)) {
434 continue;
435 }
436 }
437
438 Element record = OAIXML.createElement(OAIXML.RECORD);
439 list_records.appendChild(record);
440 //compose the header element
441 record.appendChild(createHeaderElement(oid, lastmodified));
442 //compose the metadata element
443 record.appendChild(createMetadataElement(prefix, info, metadata_format));
444
445 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
446
447 return OAIXML.getResponse(list_records);
448 }
449
450 /** get the metadataFormat element from the collectionConfig.xml containing the specified metadata prefix.
451 * return null if not found.
452 */
453 private Element getMetadataFormatElement(String prefix) {
454 Element oai = (Element)GSXML.getChildByTagName(this.coll_config_xml, OAIXML.OAI);
455 Element list_meta_format = (Element)GSXML.getChildByTagName(oai, OAIXML.LIST_METADATA_FORMATS);
456 Element metadata_format = GSXML.getNamedElement(list_meta_format, OAIXML.METADATA_FORMAT, OAIXML.METADATA_PREFIX, prefix);
457 return metadata_format;
458 }
459 /** create the metadata element used when processing ListRecords/GetRecord requests
460 */
461 private Element createMetadataElement(String prefix, DBInfo info, Element metadata_format) {
462 //the prefix string is in the form: oai_dc, for example.
463 String prfx_str = "";
464 //the metadata namespace used to retrieve metadata in the repository
465 //For example, if the prefix is like 'oai_ex' then we used 'ex' to get the metadata
466 //Normally we would use 'dc' to find metadata.
467 String meta_ns = "";
468 if(prefix.equals(OAIXML.OAI_DC)) {
469 if(OAIXML.oai_version.equals(OAIXML.OAI_VERSION2)) {
470 prfx_str = prefix + ":" + OAIXML.DC;
471 } else {
472 prfx_str = OAIXML.DC;//oai version 1
473 }
474 meta_ns = OAIXML.DC;
475 } else {
476 prfx_str = prefix.substring(prefix.indexOf("_") + 1);
477 meta_ns = prfx_str;
478 }
479 //create the <metadata> element
480 //OAIXML.oai_version is read from OAIConfig.xml and its default value is "2.0"
481 Element prfx_str_elem = OAIXML.getMetadataPrefixElement(prfx_str, OAIXML.oai_version);
482 String[] metadata_names = getMetadataNames(metadata_format);
483 HashMap meta_map = getInfoByNames(info, metadata_names);
484 ArrayList meta_list = new ArrayList(meta_map.entrySet());
485 for (int j=0; j<meta_list.size(); j++) {
486 Entry men = (Entry)meta_list.get(j);
487 String meta_name = (String)men.getKey();
488 String meta_value = (String)men.getValue();
489 Element e = OAIXML.createElement(meta_name);
490 GSXML.setNodeText(e, meta_value);
491 prfx_str_elem.appendChild(e);
492 }
493 Element metadata = OAIXML.createElement(OAIXML.METADATA);
494 metadata.appendChild(prfx_str_elem);
495 return metadata;
496 }
497 /** create a header element used when processing requests like ListRecords/GetRecord/ListIdentifiers
498 */
499 private Element createHeaderElement(String oid, String lastmodified) {
500 Element header = OAIXML.createElement(OAIXML.HEADER);
501 Element identifier = OAIXML.createElement(OAIXML.IDENTIFIER);
502 GSXML.setNodeText(identifier, site_name + ":" + coll_name + ":" + oid);
503 header.appendChild(identifier);
504 Element set_spec = OAIXML.createElement(OAIXML.SET_SPEC);
505 GSXML.setNodeText(set_spec, site_name + ":" + coll_name);
506 header.appendChild(set_spec);
507 Element datestamp = OAIXML.createElement(OAIXML.DATESTAMP);
508 GSXML.setNodeText(datestamp, lastmodified);
509 header.appendChild(datestamp);
510 return header;
511 }
512 /** return the metadata information */
513 protected Element processListMetadataFormats(Element req) {
514 // the request sent here must contain an OID. see doListMetadataFormats() in OAIReceptionist
515 Element param = GSXML.getNamedElement(req, OAIXML.PARAM, OAIXML.NAME, OAIXML.OID);
516 if (param == null) {
517 logger.error("An element containing the OID attribute not is present.");
518 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
519 }
520 String oid = param.getAttribute(OAIXML.VALUE);
521 if (oid == null || oid.equals("")) {
522 logger.error("No OID is present in the request.");
523 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
524 }
525 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
526 if (oid_list == null || oid_list.contains(oid) == false) {
527 logger.error("OID: " + oid + " is not present in the database.");
528 Element e= OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
529// logger.error((new XMLConverter()).getPrettyString (e));
530 return e;
531 }
532
533 DBInfo info = null;
534 info = this.coll_db.getInfo(oid);
535 if (info == null) { //just double check
536 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.OAI_SERVICE_UNAVAILABLE, ""));
537 }
538
539 NodeList meta_list = getMetadataFormatList(this.coll_config_xml);
540 if (meta_list == null || meta_list.getLength() == 0) {
541 logger.error("No metadata format is present in collectionConfig.xml");
542 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
543 }
544
545 Element list_metadata_formats = OAIXML.createElement(OAIXML.LIST_METADATA_FORMATS);
546 boolean has_meta_format = false;
547
548 for (int i=0; i<meta_list.getLength(); i++) {
549 Element metadata_format = (Element)meta_list.item(i);
550 String[] metadata_names = getMetadataNames(metadata_format);
551 if (containsMetadata(info, metadata_names) == true) {
552 has_meta_format = true;
553 Element meta_fmt = OAIXML.createElement(OAIXML.METADATA_FORMAT);
554 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_PREFIX);
555 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_NAMESPACE);
556 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.SCHEMA);
557 list_metadata_formats.appendChild(meta_fmt);
558 }
559 }//end of for loop
560 if (has_meta_format == false) {
561 logger.error("Specified metadata names are not contained in the database.");
562 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
563 } else {
564 return OAIXML.getResponse(list_metadata_formats);
565 }
566 }
567
568 /** return the ListMetadataFormats element in collectionConfig.xml
569 * Currently, it will only contain one metadata format: oai_dc
570 */
571 protected NodeList getMetadataFormatList(Element coll_config_xml) {
572 Element oai_elem = (Element)GSXML.getChildByTagName(coll_config_xml, OAIXML.OAI);
573 Element list_meta_formats = (Element)GSXML.getChildByTagName(oai_elem, OAIXML.LIST_METADATA_FORMATS);
574 return GSXML.getChildrenByTagName(list_meta_formats, OAIXML.METADATA_FORMAT);
575 }
576 /** @param metadata_format - the metadataFormat element in collectionConfig.xml
577 */
578 protected String[] getMetadataNames(Element metadata_format) {
579 String[] names = null;
580
581 //read the mappingList element
582 Element mapping_list = (Element)GSXML.getChildByTagName(metadata_format, OAIXML.MAPPING_LIST);
583 if (mapping_list == null) {
584 logger.info("No metadata mappings are provided in collectionConfig.xml. Use the standard Dublin Core names.");
585 names = OAIXML.getGlobalMetadataMapping(metadata_format.getAttribute(OAIXML.METADATA_PREFIX));
586
587 return (names != null)? names : OAIXML.getDublinCoreNames();
588 }
589 NodeList mappings = GSXML.getChildrenByTagName(mapping_list, OAIXML.MAPPING);
590 int size = mappings.getLength();
591 if (size == 0) {
592 logger.info("No metadata mappings are provided in collectionConfig.xml. \n Return standard DC names.");
593 // read the standard Dublin Core metadata names
594 return OAIXML.getDublinCoreNames();
595 }
596 names = new String[size];
597 for (int i=0; i<size; i++) {
598 names[i] = GSXML.getNodeText((Element)mappings.item(i)).trim();
599 }
600 return names;
601 }
602
603 /** returns a list of the child ids in order, null if no children */
604 protected ArrayList getChildrenIds(String node_id) {
605 DBInfo info = this.coll_db.getInfo(node_id);
606 if (info == null) {
607 return null;
608 }
609
610 String contains = info.getInfo("contains");
611 if (contains.equals("")) {
612 return null;
613 }
614 ArrayList children = new ArrayList();
615 StringTokenizer st = new StringTokenizer(contains, ";");
616 while (st.hasMoreTokens()) {
617 String child_id = st.nextToken().replaceAll("\"", node_id);
618 children.add(child_id);
619 }
620 return children;
621 }
622 /**method to check whether any of the 'metadata_names' is contained in the 'info'.
623 * The name may be in the form: <name>,<mapped name>, in which the mapped name is
624 * optional. The mapped name is looked up in the DBInfo; if not present, use the first
625 * name which is mendatory.
626 */
627 protected boolean containsMetadata(DBInfo info, String[] metadata_names) {
628 if (metadata_names == null) return false;
629 logger.info("checking metadata names in db.");
630 for(int i=0; i<metadata_names.length; i++) {
631 int index = metadata_names[i].indexOf(",");
632 String meta_name = (index == -1) ? metadata_names[i] :
633 metadata_names[i].substring(index + 1);
634
635 if(info.getInfo(meta_name).equals("") == false) {
636 return true;
637 }
638 }
639 return false;
640 }
641 /** @param keys - contains a list of keys in string format.
642 * Here is a typical record in the collection database, 'keys' contains the values in <...>:
643 *----------------------------------------------------------------------
644[HASH01a84acb0f1aad2380493b3a]
645<doctype>doc
646<hastxt>1
647<Language>en
648<Encoding>windows_1252
649<Plugin>HTMLPlug
650<FileSize>205093
651<Source>wb34te.htm
652<hascover>1
653<dls.Organization>World Bank
654<dls.Title>Development in practice: Toward Gender Equality (wb34te)
655<dls.Language>English
656<dls.AZList>A-B-C-D-E-F-G-H-I-J-K-L-M-N-O-P-Q-R-S-T-U-V-W-X-Y-Z
657<dls.Subject>Women, gender and development, women's organizations
658<dls.Keyword>achieve gender equality
659<URL>http://wb34te/wb34te.htm
660<Title>Development in practice: Toward Gender Equality
661<lastmodified>1178245194
662<assocfilepath>HASH01a8.dir
663<memberof>CL3
664<archivedir>HASH01a8.dir
665<thistype>VList
666<childtype>VList
667<contains>".1;".2;".3;".4;".5;".6;".7;".8;".9
668<docnum>349
669----------------------------------------------------------------------
670 */
671 public String[] getMetadata(DBInfo info, String names) {
672 String[] name_value = new String[2];
673 ArrayList keys = new ArrayList(info.getKeys());
674 for (int i=0; i<keys.size(); i++) {
675 String key = (String)keys.get(i);
676 String first_name = "";
677 String second_name = "";
678 int index = names.indexOf(",");
679 if(index != -1) {
680 first_name = names.substring(0, index);
681 second_name = names.substring(index + 1);
682 } else {
683 first_name = second_name = names;
684 }
685 if(key.equals(second_name)) {
686 String meta_value = info.getInfo(key);
687 name_value[0] = first_name;
688 name_value[1] = meta_value;
689 return name_value;
690 }
691 }
692 return null;
693 }
694 protected HashMap getInfoByNames(DBInfo info, String[] metadata_names) {
695 HashMap map = new HashMap();
696 boolean empty_map = true;
697
698 for(int i=0; i<metadata_names.length; i++) {
699 String[] name_value = getMetadata(info, metadata_names[i]);
700 if(name_value != null) {
701 map.put(name_value[0], name_value[1]);
702 empty_map = false;
703 }
704 }
705 return (empty_map == true) ? null : map;
706 }
707}
708
709
Note: See TracBrowser for help on using the repository browser.