source: greenstone3/trunk/src/java/org/greenstone/gsdl3/service/OAIPMH.java@ 15326

Last change on this file since 15326 was 15326, checked in by kjdon, 16 years ago

added support for JDBM (or other) in place of GDBM: use SimpleCollectionDatabase instead of GDBMWrapper. new Element in buildConfig file: databaseType, set to gdbm or jdbm. If not present, assume gdbm. Also may be some small style changes to some files
File size: 28.2 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 //add_service.setAttribute(GSXML.TYPE_ATT, "gather"); // why do we need this?
130 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
131 this.short_service_info.appendChild(identify);
132
133 Element list_records = this.doc.createElement(OAIXML.SERVICE);
134 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
135 this.short_service_info.appendChild(list_records);
136
137 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
138 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
139 this.short_service_info.appendChild(list_identifiers);
140
141 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
142 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
143 this.short_service_info.appendChild(list_sets);
144
145 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
146 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
147 this.short_service_info.appendChild(list_metadata_formats);
148
149 Element get_record = this.doc.createElement(OAIXML.SERVICE);
150 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
151 this.short_service_info.appendChild(get_record);
152
153 return true;
154 }
155 /** returns a specific service description */
156 public Element getServiceDescription(String service_id, String lang, String subset) {
157
158 if (service_id.equals(OAIXML.IDENTIFY)) {
159 Element identify = this.doc.createElement(OAIXML.SERVICE);
160 //add_service.setAttribute(GSXML.TYPE_ATT, "gather"); // why do we need this?
161 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
162 return identify;
163 }
164 if (service_id.equals(OAIXML.LIST_RECORDS)) {
165 Element list_records = this.doc.createElement(OAIXML.SERVICE);
166 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
167 return list_records;
168 }
169
170 if (service_id.equals(OAIXML.LIST_IDENTIFIERS)) {
171 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
172 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
173 return list_identifiers;
174 }
175 if (service_id.equals(OAIXML.LIST_SETS)) {
176 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
177 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
178 return list_sets;
179 }
180 if (service_id.equals(OAIXML.LIST_METADATA_FORMATS)) {
181 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
182 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
183 return list_metadata_formats;
184 }
185
186 if (service_id.equals(OAIXML.GET_RECORD)) {
187 Element get_record = this.doc.createElement(OAIXML.SERVICE);
188 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
189 return get_record;
190 }
191
192 return null;
193 }
194 /** return the metadata information about this set of the repository */
195 protected Element processIdentify(Element req) {
196 return null;
197 }
198 /** return the metadata information */
199 protected Element processListSets(Element req) {
200 //This method is never called unless each set in the returned message contain a
201 //'description' element so that we need to ask each collection for their info
202 return null;
203 }
204 /** return the metadata information */
205 protected Element processGetRecord(Element req) {
206 /** arguments:
207 identifier: required
208 metadataPrefix: required
209 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
210 */
211 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
212 HashMap param_map = OAIXML.getParamMap(params);
213
214 String prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
215 if (prefix == null || prefix.equals("")) {
216 //Just a double-check
217 logger.error("the value of metadataPrefix att is not present in the request.");
218 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
219 }
220
221 Element metadata_format = getMetadataFormatElement(prefix);
222 if(metadata_format == null) {
223 logger.error("metadata prefix is not supported.");
224 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
225 }
226
227 String oid = (String)param_map.get(OAIXML.OID);
228
229 //get a DBInfo object of the identifier; if this identifier is not present in the database,
230 // null is returned.
231 DBInfo info = this.coll_db.getInfo(oid);
232 if (info == null) {
233 logger.error("OID: " + oid + " is not present in the database.");
234 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
235 }
236
237 ArrayList keys = new ArrayList(info.getKeys());
238 String lastmodified = "";
239 if(keys.contains(OAIXML.LASTMODIFIED)) {
240 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
241 }
242 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
243
244 Element get_record = OAIXML.createElement(OAIXML.GET_RECORD);
245 Element record = OAIXML.createElement(OAIXML.RECORD);
246 //compose the header element
247 record.appendChild(createHeaderElement(oid, lastmodified));
248 //compose the metadata element
249 record.appendChild(createMetadataElement(prefix, info, metadata_format));
250 get_record.appendChild(record);
251 return OAIXML.getResponse(get_record);
252 }
253 /** return a list of identifiers */
254 protected Element processListIdentifiers(Element req) {
255 /** arguments:
256 metadataPrefix: required
257 * from: optional
258 * until: optional
259 * set: optional
260 * resumptionToken: exclusive and optional (ignored as it has been handled by OAIReceptionist)
261 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
262 */
263 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
264
265 if(params.getLength() == 0) {
266 logger.error("must at least have the metadataPrefix parameter, can't be none");
267 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
268 }
269
270 HashMap param_map = OAIXML.getParamMap(params);
271
272 String prefix = "";
273 Date from_date = null;
274 Date until_date = null;
275
276 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
277 //Just a double-check
278 logger.error("A param element containing the metadataPrefix is not present.");
279 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
280 }
281 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
282 if (prefix == null || prefix.equals("")) {
283 //Just a double-check
284 logger.error("the value of metadataPrefix att is not present in the request.");
285 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
286 }
287
288 if(param_map.containsKey(OAIXML.FROM)) {
289 String from = (String)param_map.get(OAIXML.FROM);
290 from_date = OAIXML.getDate(from);
291 }
292 if(param_map.containsKey(OAIXML.UNTIL)) {
293 String until = (String)param_map.get(OAIXML.UNTIL);
294 until_date = OAIXML.getDate(until);
295 }
296
297 Element metadata_format = getMetadataFormatElement(prefix);
298 if(metadata_format == null) {
299 logger.error("metadata prefix is not supported.");
300 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
301 }
302 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
303 if (oid_list == null) {
304 logger.error("No matched records found in collection: browselist is empty");
305 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
306 }
307 // all validation is done
308 Element list_identifiers = OAIXML.createElement(OAIXML.LIST_IDENTIFIERS);
309 for(int i=0; i<oid_list.size(); i++) {
310 String oid = (String)oid_list.get(i);
311 DBInfo info = this.coll_db.getInfo(oid);
312 if (info == null) {
313 logger.error("Database does not contains information about oid: " +oid);
314 continue;
315 }
316 ArrayList keys = new ArrayList(info.getKeys());
317 String lastmodified = "";
318 if(keys.contains(OAIXML.LASTMODIFIED)) {
319 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
320 }
321 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
322
323 Date this_date = OAIXML.getDate(lastmodified);
324 if (from_date != null) {
325 if(this_date.before(from_date)) {
326 continue;
327 }
328 }
329 if (until_date != null) {
330 if (this_date.after(until_date)) {
331 continue;
332 }
333 }
334 //compose the header element and append it
335 list_identifiers.appendChild(createHeaderElement(oid, lastmodified));
336 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
337
338 return OAIXML.getResponse(list_identifiers);
339 }
340 /** return a list of records */
341 protected Element processListRecords(Element req) {
342 /** the request sent here may contain optional 'from', 'untill', 'metadataPrefix',
343 * and 'resumptionToken' params. see doListSets() in OAIReceptionist.
344 * if the request contains 'resumptionToken' then it should have been handled by the
345 * OAIReceptionist. Therefore, the request sent here must not contain 'resumptionToken'
346 * argument but a 'metadataPrefix' param. The OAIReceptionist makes sure of this.
347 */
348 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
349
350 if(params.getLength() == 0) {
351 logger.error("must at least have the metadataPrefix parameter, can't be none");
352 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
353 }
354
355 HashMap param_map = OAIXML.getParamMap(params);
356
357 String prefix = "";
358 Date from_date = null;
359 Date until_date = null;
360
361 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
362 //Just a double-check
363 logger.error("A param element containing the metadataPrefix is not present.");
364 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
365 }
366 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
367 if (prefix == null || prefix.equals("")) {
368 //Just a double-check
369 logger.error("the value of metadataPrefix att is not present in the request.");
370 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
371 }
372
373 if(param_map.containsKey(OAIXML.FROM)) {
374 String from = (String)param_map.get(OAIXML.FROM);
375 from_date = OAIXML.getDate(from);
376 }
377 if(param_map.containsKey(OAIXML.UNTIL)) {
378 String until = (String)param_map.get(OAIXML.UNTIL);
379 until_date = OAIXML.getDate(until);
380 }
381 Element metadata_format = getMetadataFormatElement(prefix);
382 if(metadata_format == null) {
383 logger.error("metadata prefix is not supported.");
384 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
385 }
386// Another way of doing the same job!
387// HashMap prefix_map = OAIXML.getChildrenMapByTagName(coll_config_xml, OAIXML.METADATA_PREFIX);
388// if(!prefix_map.contains(prefix)) {
389// logger.error("metadata prefix is not supported.");
390// return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
391// }
392
393 //get a list of identifiers (it contains a list of strings)
394 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
395 if (oid_list == null) {
396 logger.error("No matched records found in collection: browselist is empty");
397 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
398 }
399 // all validation is done
400 Element list_records = OAIXML.createElement(OAIXML.LIST_RECORDS);
401 for(int i=0; i<oid_list.size(); i++) {
402 String oid = (String)oid_list.get(i);
403 DBInfo info = this.coll_db.getInfo(oid);
404 if (info == null) {
405 logger.error("Database does not contains information about oid: " +oid);
406 continue;
407 }
408 ArrayList keys = new ArrayList(info.getKeys());
409 String lastmodified = "";
410 if(keys.contains(OAIXML.LASTMODIFIED)) {
411 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
412 }
413 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
414
415 Date this_date = OAIXML.getDate(lastmodified);
416 if (from_date != null) {
417 if(this_date.before(from_date)) {
418 continue;
419 }
420 }
421 if (until_date != null) {
422 if (this_date.after(until_date)) {
423 continue;
424 }
425 }
426
427 Element record = OAIXML.createElement(OAIXML.RECORD);
428 list_records.appendChild(record);
429 //compose the header element
430 record.appendChild(createHeaderElement(oid, lastmodified));
431 //compose the metadata element
432 record.appendChild(createMetadataElement(prefix, info, metadata_format));
433
434 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
435
436 return OAIXML.getResponse(list_records);
437 }
438
439 /** get the metadataFormat element from the collectionConfig.xml containing the specified metadata prefix.
440 * return null if not found.
441 */
442 private Element getMetadataFormatElement(String prefix) {
443 Element oai = (Element)GSXML.getChildByTagName(this.coll_config_xml, OAIXML.OAI);
444 Element list_meta_format = (Element)GSXML.getChildByTagName(oai, OAIXML.LIST_METADATA_FORMATS);
445 Element metadata_format = GSXML.getNamedElement(list_meta_format, OAIXML.METADATA_FORMAT, OAIXML.METADATA_PREFIX, prefix);
446 return metadata_format;
447 }
448 /** create the metadata element used when processing ListRecords/GetRecord requests
449 */
450 private Element createMetadataElement(String prefix, DBInfo info, Element metadata_format) {
451 //the prefix string is in the form: oai_dc, for example.
452 String prfx_str = "";
453 //the metadata namespace used to retrieve metadata in the repository
454 //For example, if the prefix is like 'oai_ex' then we used 'ex' to get the metadata
455 //Normally we would use 'dc' to find metadata.
456 String meta_ns = "";
457 if(prefix.equals(OAIXML.OAI_DC)) {
458 if(OAIXML.oai_version.equals(OAIXML.OAI_VERSION2)) {
459 prfx_str = prefix + ":" + OAIXML.DC;
460 } else {
461 prfx_str = OAIXML.DC;//oai version 1
462 }
463 meta_ns = OAIXML.DC;
464 } else {
465 prfx_str = prefix.substring(prefix.indexOf("_") + 1);
466 meta_ns = prfx_str;
467 }
468 //create the <metadata> element
469 //OAIXML.oai_version is read from OAIConfig.xml and its default value is "2.0"
470 Element prfx_str_elem = OAIXML.getMetadataPrefixElement(prfx_str, OAIXML.oai_version);
471 String[] metadata_names = getMetadataNames(metadata_format);
472 HashMap meta_map = getInfoByNames(info, metadata_names);
473 ArrayList meta_list = new ArrayList(meta_map.entrySet());
474 for (int j=0; j<meta_list.size(); j++) {
475 Entry men = (Entry)meta_list.get(j);
476 String meta_name = (String)men.getKey();
477 String meta_value = (String)men.getValue();
478 Element e = OAIXML.createElement(meta_name);
479 GSXML.setNodeText(e, meta_value);
480 prfx_str_elem.appendChild(e);
481 }
482 Element metadata = OAIXML.createElement(OAIXML.METADATA);
483 metadata.appendChild(prfx_str_elem);
484 return metadata;
485 }
486 /** create a header element used when processing requests like ListRecords/GetRecord/ListIdentifiers
487 */
488 private Element createHeaderElement(String oid, String lastmodified) {
489 Element header = OAIXML.createElement(OAIXML.HEADER);
490 Element identifier = OAIXML.createElement(OAIXML.IDENTIFIER);
491 GSXML.setNodeText(identifier, site_name + ":" + coll_name + ":" + oid);
492 header.appendChild(identifier);
493 Element set_spec = OAIXML.createElement(OAIXML.SET_SPEC);
494 GSXML.setNodeText(set_spec, site_name + ":" + coll_name);
495 header.appendChild(set_spec);
496 Element datestamp = OAIXML.createElement(OAIXML.DATESTAMP);
497 GSXML.setNodeText(datestamp, lastmodified);
498 header.appendChild(datestamp);
499 return header;
500 }
501 /** return the metadata information */
502 protected Element processListMetadataFormats(Element req) {
503 // the request sent here must contain an OID. see doListMetadataFormats() in OAIReceptionist
504 Element param = GSXML.getNamedElement(req, OAIXML.PARAM, OAIXML.NAME, OAIXML.OID);
505 if (param == null) {
506 logger.error("An element containing the OID attribute not is present.");
507 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
508 }
509 String oid = param.getAttribute(OAIXML.VALUE);
510 if (oid == null || oid.equals("")) {
511 logger.error("No OID is present in the request.");
512 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
513 }
514 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
515 if (oid_list == null || oid_list.contains(oid) == false) {
516 logger.error("OID: " + oid + " is not present in the database.");
517 Element e= OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
518// logger.error((new XMLConverter()).getPrettyString (e));
519 return e;
520 }
521
522 DBInfo info = null;
523 info = this.coll_db.getInfo(oid);
524 if (info == null) { //just double check
525 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.OAI_SERVICE_UNAVAILABLE, ""));
526 }
527
528 NodeList meta_list = getMetadataFormatList(this.coll_config_xml);
529 if (meta_list == null || meta_list.getLength() == 0) {
530 logger.error("No metadata format is present in collectionConfig.xml");
531 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
532 }
533
534 Element list_metadata_formats = OAIXML.createElement(OAIXML.LIST_METADATA_FORMATS);
535 boolean has_meta_format = false;
536
537 for (int i=0; i<meta_list.getLength(); i++) {
538 Element metadata_format = (Element)meta_list.item(i);
539 String[] metadata_names = getMetadataNames(metadata_format);
540 if (containsMetadata(info, metadata_names) == true) {
541 has_meta_format = true;
542 Element meta_fmt = OAIXML.createElement(OAIXML.METADATA_FORMAT);
543 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_PREFIX);
544 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_NAMESPACE);
545 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.SCHEMA);
546 list_metadata_formats.appendChild(meta_fmt);
547 }
548 }//end of for loop
549 if (has_meta_format == false) {
550 logger.error("Specified metadata names are not contained in the database.");
551 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
552 } else {
553 return OAIXML.getResponse(list_metadata_formats);
554 }
555 }
556
557 /** return the ListMetadataFormats element in collectionConfig.xml
558 * Currently, it will only contain one metadata format: oai_dc
559 */
560 protected NodeList getMetadataFormatList(Element coll_config_xml) {
561 Element oai_elem = (Element)GSXML.getChildByTagName(coll_config_xml, OAIXML.OAI);
562 Element list_meta_formats = (Element)GSXML.getChildByTagName(oai_elem, OAIXML.LIST_METADATA_FORMATS);
563 return GSXML.getChildrenByTagName(list_meta_formats, OAIXML.METADATA_FORMAT);
564 }
565 /** @param metadata_format - the metadataFormat element in collectionConfig.xml
566 */
567 protected String[] getMetadataNames(Element metadata_format) {
568 String[] names = null;
569
570 //read the mappingList element
571 Element mapping_list = (Element)GSXML.getChildByTagName(metadata_format, OAIXML.MAPPING_LIST);
572 if (mapping_list == null) {
573 logger.info("No metadata mappings are provided in collectionConfig.xml. Use the standard Dublin Core names.");
574 names = OAIXML.getGlobalMetadataMapping(metadata_format.getAttribute(OAIXML.METADATA_PREFIX));
575
576 return (names != null)? names : OAIXML.getDublinCoreNames();
577 }
578 NodeList mappings = GSXML.getChildrenByTagName(mapping_list, OAIXML.MAPPING);
579 int size = mappings.getLength();
580 if (size == 0) {
581 logger.info("No metadata mappings are provided in collectionConfig.xml. \n Return standard DC names.");
582 // read the standard Dublin Core metadata names
583 return OAIXML.getDublinCoreNames();
584 }
585 names = new String[size];
586 for (int i=0; i<size; i++) {
587 names[i] = GSXML.getNodeText((Element)mappings.item(i)).trim();
588 }
589 return names;
590 }
591
592 /** returns a list of the child ids in order, null if no children */
593 protected ArrayList getChildrenIds(String node_id) {
594 DBInfo info = this.coll_db.getInfo(node_id);
595 if (info == null) {
596 return null;
597 }
598
599 String contains = info.getInfo("contains");
600 if (contains.equals("")) {
601 return null;
602 }
603 ArrayList children = new ArrayList();
604 StringTokenizer st = new StringTokenizer(contains, ";");
605 while (st.hasMoreTokens()) {
606 String child_id = st.nextToken().replaceAll("\"", node_id);
607 children.add(child_id);
608 }
609 return children;
610 }
611 /**method to check whether any of the 'metadata_names' is contained in the 'info'.
612 * The name may be in the form: <name>,<mapped name>, in which the mapped name is
613 * optional. The mapped name is looked up in the DBInfo; if not present, use the first
614 * name which is mendatory.
615 */
616 protected boolean containsMetadata(DBInfo info, String[] metadata_names) {
617 if (metadata_names == null) return false;
618 logger.info("checking metadata names in db.");
619 for(int i=0; i<metadata_names.length; i++) {
620 int index = metadata_names[i].indexOf(",");
621 String meta_name = (index == -1) ? metadata_names[i] :
622 metadata_names[i].substring(index + 1);
623
624 if(info.getInfo(meta_name).equals("") == false) {
625 return true;
626 }
627 }
628 return false;
629 }
630 /** @param keys - contains a list of keys in string format.
631 * Here is a typical record in the collection database, 'keys' contains the values in <...>:
632 *----------------------------------------------------------------------
633[HASH01a84acb0f1aad2380493b3a]
634<doctype>doc
635<hastxt>1
636<Language>en
637<Encoding>windows_1252
638<Plugin>HTMLPlug
639<FileSize>205093
640<Source>wb34te.htm
641<hascover>1
642<dls.Organization>World Bank
643<dls.Title>Development in practice: Toward Gender Equality (wb34te)
644<dls.Language>English
645<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
646<dls.Subject>Women, gender and development, women's organizations
647<dls.Keyword>achieve gender equality
648<URL>http://wb34te/wb34te.htm
649<Title>Development in practice: Toward Gender Equality
650<lastmodified>1178245194
651<assocfilepath>HASH01a8.dir
652<memberof>CL3
653<archivedir>HASH01a8.dir
654<thistype>VList
655<childtype>VList
656<contains>".1;".2;".3;".4;".5;".6;".7;".8;".9
657<docnum>349
658----------------------------------------------------------------------
659 */
660 public String[] getMetadata(DBInfo info, String names) {
661 String[] name_value = new String[2];
662 ArrayList keys = new ArrayList(info.getKeys());
663 for (int i=0; i<keys.size(); i++) {
664 String key = (String)keys.get(i);
665 String first_name = "";
666 String second_name = "";
667 int index = names.indexOf(",");
668 if(index != -1) {
669 first_name = names.substring(0, index);
670 second_name = names.substring(index + 1);
671 } else {
672 first_name = second_name = names;
673 }
674 if(key.equals(second_name)) {
675 String meta_value = info.getInfo(key);
676 name_value[0] = first_name;
677 name_value[1] = meta_value;
678 return name_value;
679 }
680 }
681 return null;
682 }
683 protected HashMap getInfoByNames(DBInfo info, String[] metadata_names) {
684 HashMap map = new HashMap();
685 boolean empty_map = true;
686
687 for(int i=0; i<metadata_names.length; i++) {
688 String[] name_value = getMetadata(info, metadata_names[i]);
689 if(name_value != null) {
690 map.put(name_value[0], name_value[1]);
691 empty_map = false;
692 }
693 }
694 return (empty_map == true) ? null : map;
695 }
696}
697
698
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