source: greenstone3/trunk/src/java/org/greenstone/gsdl3/service/OAIPMH.java@ 14209

Last change on this file since 14209 was 14209, checked in by xiao, 17 years ago

an OAI metadata providing service class
File size: 27.5 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.GDBMWrapper;
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.*;
48
49/** Implements the oai metadata retrieval service for GS3 collections.
50 * Dig into each collection's gdbm 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 GDBMWrapper gdbm_src = 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 this.gdbm_src = new GDBMWrapper();
68 }
69
70 public void cleanUp() {
71 super.cleanUp();//??
72 this.gdbm_src.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 // Open GDBM database for querying
102 String gdbm_db_file = GSFile.GDBMDatabaseFile(this.site_home, this.cluster_name, index_stem);
103 if (!this.gdbm_src.openDatabase(gdbm_db_file, GDBMWrapper.READER)) {
104 logger.error("Could not open GDBM database!");
105 return false;
106 }
107
108 // the short_service_info is used by the message router to find the method names,
109 //so we just use the doc variable in class ServiceRack to create the xml; but
110 // in each method we will use OAIXML to create the response xml
111 // set up short_service_info_ - just the name
112
113 Element identify = this.doc.createElement(OAIXML.SERVICE);
114 //add_service.setAttribute(GSXML.TYPE_ATT, "gather"); // why do we need this?
115 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
116 this.short_service_info.appendChild(identify);
117
118 Element list_records = this.doc.createElement(OAIXML.SERVICE);
119 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
120 this.short_service_info.appendChild(list_records);
121
122 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
123 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
124 this.short_service_info.appendChild(list_identifiers);
125
126 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
127 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
128 this.short_service_info.appendChild(list_sets);
129
130 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
131 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
132 this.short_service_info.appendChild(list_metadata_formats);
133
134 Element get_record = this.doc.createElement(OAIXML.SERVICE);
135 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
136 this.short_service_info.appendChild(get_record);
137
138 return true;
139 }
140 /** returns a specific service description */
141 public Element getServiceDescription(String service_id, String lang, String subset) {
142
143 if (service_id.equals(OAIXML.IDENTIFY)) {
144 Element identify = this.doc.createElement(OAIXML.SERVICE);
145 //add_service.setAttribute(GSXML.TYPE_ATT, "gather"); // why do we need this?
146 identify.setAttribute(OAIXML.NAME, OAIXML.IDENTIFY);
147 return identify;
148 }
149 if (service_id.equals(OAIXML.LIST_RECORDS)) {
150 Element list_records = this.doc.createElement(OAIXML.SERVICE);
151 list_records.setAttribute(OAIXML.NAME, OAIXML.LIST_RECORDS);
152 return list_records;
153 }
154
155 if (service_id.equals(OAIXML.LIST_IDENTIFIERS)) {
156 Element list_identifiers = this.doc.createElement(OAIXML.SERVICE);
157 list_identifiers.setAttribute(OAIXML.NAME, OAIXML.LIST_IDENTIFIERS);
158 return list_identifiers;
159 }
160 if (service_id.equals(OAIXML.LIST_SETS)) {
161 Element list_sets = this.doc.createElement(OAIXML.SERVICE);
162 list_sets.setAttribute(OAIXML.NAME, OAIXML.LIST_SETS);
163 return list_sets;
164 }
165 if (service_id.equals(OAIXML.LIST_METADATA_FORMATS)) {
166 Element list_metadata_formats = this.doc.createElement(OAIXML.SERVICE);
167 list_metadata_formats.setAttribute(OAIXML.NAME, OAIXML.LIST_METADATA_FORMATS);
168 return list_metadata_formats;
169 }
170
171 if (service_id.equals(OAIXML.GET_RECORD)) {
172 Element get_record = this.doc.createElement(OAIXML.SERVICE);
173 get_record.setAttribute(OAIXML.NAME, OAIXML.GET_RECORD);
174 return get_record;
175 }
176
177 return null;
178 }
179 /** return the metadata information about this set of the repository */
180 protected Element processIdentify(Element req) {
181 return null;
182 }
183 /** return the metadata information */
184 protected Element processListSets(Element req) {
185 //This method is never called unless each set in the returned message contain a
186 //'description' element so that we need to ask each collection for their info
187 return null;
188 }
189 /** return the metadata information */
190 protected Element processGetRecord(Element req) {
191 /** arguments:
192 identifier: required
193 metadataPrefix: required
194 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
195 */
196 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
197 HashMap param_map = OAIXML.getParamMap(params);
198
199 String prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
200 if (prefix == null || prefix.equals("")) {
201 //Just a double-check
202 logger.error("the value of metadataPrefix att is not present in the request.");
203 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
204 }
205
206 Element metadata_format = getMetadataFormatElement(prefix);
207 if(metadata_format == null) {
208 logger.error("metadata prefix is not supported.");
209 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
210 }
211
212 String oid = (String)param_map.get(OAIXML.OID);
213
214 //get a DBInfo object of the identifier; if this identifier is not present in the database,
215 // null is returned.
216 DBInfo info = this.gdbm_src.getInfo(oid);
217 if (info == null) {
218 logger.error("OID: " + oid + " is not present in the database.");
219 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
220 }
221
222 ArrayList keys = new ArrayList(info.getKeys());
223 String lastmodified = "";
224 if(keys.contains(OAIXML.LASTMODIFIED)) {
225 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
226 }
227 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
228
229 Element get_record = OAIXML.createElement(OAIXML.GET_RECORD);
230 Element record = OAIXML.createElement(OAIXML.RECORD);
231 //compose the header element
232 record.appendChild(createHeaderElement(oid, lastmodified));
233 //compose the metadata element
234 record.appendChild(createMetadataElement(prefix, info, metadata_format));
235 get_record.appendChild(record);
236 return OAIXML.getResponse(get_record);
237 }
238 /** return a list of identifiers */
239 protected Element processListIdentifiers(Element req) {
240 /** arguments:
241 metadataPrefix: required
242 * from: optional
243 * until: optional
244 * set: optional
245 * resumptionToken: exclusive and optional (ignored as it has been handled by OAIReceptionist)
246 * Exceptions: badArgument; cannotDisseminateFormat; idDoesNotExist
247 */
248 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
249
250 if(params.getLength() == 0) {
251 logger.error("must at least have the metadataPrefix parameter, can't be none");
252 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
253 }
254
255 HashMap param_map = OAIXML.getParamMap(params);
256
257 String prefix = "";
258 Date from_date = null;
259 Date until_date = null;
260
261 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
262 //Just a double-check
263 logger.error("A param element containing the metadataPrefix is not present.");
264 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
265 }
266 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
267 if (prefix == null || prefix.equals("")) {
268 //Just a double-check
269 logger.error("the value of metadataPrefix att is not present in the request.");
270 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
271 }
272
273 if(param_map.containsKey(OAIXML.FROM)) {
274 String from = (String)param_map.get(OAIXML.FROM);
275 from_date = OAIXML.getDate(from);
276 }
277 if(param_map.containsKey(OAIXML.UNTIL)) {
278 String until = (String)param_map.get(OAIXML.UNTIL);
279 until_date = OAIXML.getDate(until);
280 }
281
282 Element metadata_format = getMetadataFormatElement(prefix);
283 if(metadata_format == null) {
284 logger.error("metadata prefix is not supported.");
285 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
286 }
287 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
288 if (oid_list == null) {
289 logger.error("No matched records found in collection: browselist is empty");
290 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
291 }
292 // all validation is done
293 Element list_identifiers = OAIXML.createElement(OAIXML.LIST_IDENTIFIERS);
294 for(int i=0; i<oid_list.size(); i++) {
295 String oid = (String)oid_list.get(i);
296 DBInfo info = this.gdbm_src.getInfo(oid);
297 if (info == null) {
298 logger.error("Database does not contains information about oid: " +oid);
299 continue;
300 }
301 ArrayList keys = new ArrayList(info.getKeys());
302 String lastmodified = "";
303 if(keys.contains(OAIXML.LASTMODIFIED)) {
304 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
305 }
306 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
307
308 Date this_date = OAIXML.getDate(lastmodified);
309 if (from_date != null) {
310 if(this_date.before(from_date)) {
311 continue;
312 }
313 }
314 if (until_date != null) {
315 if (this_date.after(until_date)) {
316 continue;
317 }
318 }
319 //compose the header element and append it
320 list_identifiers.appendChild(createHeaderElement(oid, lastmodified));
321 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
322
323 return OAIXML.getResponse(list_identifiers);
324 }
325 /** return a list of records */
326 protected Element processListRecords(Element req) {
327 /** the request sent here may contain optional 'from', 'untill', 'metadataPrefix',
328 * and 'resumptionToken' params. see doListSets() in OAIReceptionist.
329 * if the request contains 'resumptionToken' then it should have been handled by the
330 * OAIReceptionist. Therefore, the request sent here must not contain 'resumptionToken'
331 * argument but a 'metadataPrefix' param. The OAIReceptionist makes sure of this.
332 */
333 NodeList params = GSXML.getChildrenByTagName(req, OAIXML.PARAM);
334
335 if(params.getLength() == 0) {
336 logger.error("must at least have the metadataPrefix parameter, can't be none");
337 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.BAD_ARGUMENT, ""));
338 }
339
340 HashMap param_map = OAIXML.getParamMap(params);
341
342 String prefix = "";
343 Date from_date = null;
344 Date until_date = null;
345
346 if(param_map.containsKey(OAIXML.METADATA_PREFIX) == false) {
347 //Just a double-check
348 logger.error("A param element containing the metadataPrefix is not present.");
349 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
350 }
351 prefix = (String)param_map.get(OAIXML.METADATA_PREFIX);
352 if (prefix == null || prefix.equals("")) {
353 //Just a double-check
354 logger.error("the value of metadataPrefix att is not present in the request.");
355 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
356 }
357
358 if(param_map.containsKey(OAIXML.FROM)) {
359 String from = (String)param_map.get(OAIXML.FROM);
360 from_date = OAIXML.getDate(from);
361 }
362 if(param_map.containsKey(OAIXML.UNTIL)) {
363 String until = (String)param_map.get(OAIXML.UNTIL);
364 until_date = OAIXML.getDate(until);
365 }
366 Element metadata_format = getMetadataFormatElement(prefix);
367 if(metadata_format == null) {
368 logger.error("metadata prefix is not supported.");
369 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
370 }
371// Another way of doing the same job!
372// HashMap prefix_map = OAIXML.getChildrenMapByTagName(coll_config_xml, OAIXML.METADATA_PREFIX);
373// if(!prefix_map.contains(prefix)) {
374// logger.error("metadata prefix is not supported.");
375// return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.CANNOT_DISSEMINATE_FORMAT, ""));
376// }
377
378 //get a list of identifiers (it contains a list of strings)
379 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
380 if (oid_list == null) {
381 logger.error("No matched records found in collection: browselist is empty");
382 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_RECORDS_MATCH, ""));
383 }
384 // all validation is done
385 Element list_records = OAIXML.createElement(OAIXML.LIST_RECORDS);
386 for(int i=0; i<oid_list.size(); i++) {
387 String oid = (String)oid_list.get(i);
388 DBInfo info = this.gdbm_src.getInfo(oid);
389 if (info == null) {
390 logger.error("Database does not contains information about oid: " +oid);
391 continue;
392 }
393 ArrayList keys = new ArrayList(info.getKeys());
394 String lastmodified = "";
395 if(keys.contains(OAIXML.LASTMODIFIED)) {
396 lastmodified = info.getInfo(OAIXML.LASTMODIFIED);
397 }
398 lastmodified = OAIXML.getTime(Long.parseLong(lastmodified));
399
400 Date this_date = OAIXML.getDate(lastmodified);
401 if (from_date != null) {
402 if(this_date.before(from_date)) {
403 continue;
404 }
405 }
406 if (until_date != null) {
407 if (this_date.after(until_date)) {
408 continue;
409 }
410 }
411
412 Element record = OAIXML.createElement(OAIXML.RECORD);
413 list_records.appendChild(record);
414 //compose the header element
415 record.appendChild(createHeaderElement(oid, lastmodified));
416 //compose the metadata element
417 record.appendChild(createMetadataElement(prefix, info, metadata_format));
418
419 }//end of for(int i=0; i<oid_list.size(); i++) of doing thru each record
420
421 return OAIXML.getResponse(list_records);
422 }
423
424 /** get the metadataFormat element from the collectionConfig.xml containing the specified metadata prefix.
425 * return null if not found.
426 */
427 private Element getMetadataFormatElement(String prefix) {
428 Element oai = (Element)GSXML.getChildByTagName(this.coll_config_xml, OAIXML.OAI);
429 Element list_meta_format = (Element)GSXML.getChildByTagName(oai, OAIXML.LIST_METADATA_FORMATS);
430 Element metadata_format = GSXML.getNamedElement(list_meta_format, OAIXML.METADATA_FORMAT, OAIXML.METADATA_PREFIX, prefix);
431 return metadata_format;
432 }
433 /** create the metadata element used when processing ListRecords/GetRecord requests
434 */
435 private Element createMetadataElement(String prefix, DBInfo info, Element metadata_format) {
436 //the prefix string is in the form: oai_dc, for example.
437 String prfx_str = "";
438 //the metadata namespace used to retrieve metadata in the repository
439 //For example, if the prefix is like 'oai_ex' then we used 'ex' to get the metadata
440 //Normally we would use 'dc' to find metadata.
441 String meta_ns = "";
442 if(prefix.equals(OAIXML.OAI_DC)) {
443 if(OAIXML.oai_version.equals(OAIXML.OAI_VERSION2)) {
444 prfx_str = prefix + ":" + OAIXML.DC;
445 } else {
446 prfx_str = OAIXML.DC;//oai version 1
447 }
448 meta_ns = OAIXML.DC;
449 } else {
450 prfx_str = prefix.substring(prefix.indexOf("_") + 1);
451 meta_ns = prfx_str;
452 }
453 //create the <metadata> element
454 //OAIXML.oai_version is read from OAIConfig.xml and its default value is "2.0"
455 Element prfx_str_elem = OAIXML.getMetadataPrefixElement(prfx_str, OAIXML.oai_version);
456 String[] metadata_names = getMetadataNames(metadata_format);
457 HashMap meta_map = getInfoByNames(info, metadata_names);
458 ArrayList meta_list = new ArrayList(meta_map.entrySet());
459 for (int j=0; j<meta_list.size(); j++) {
460 Entry men = (Entry)meta_list.get(j);
461 String meta_name = (String)men.getKey();
462 String meta_value = (String)men.getValue();
463 Element e = OAIXML.createElement(meta_name);
464 GSXML.setNodeText(e, meta_value);
465 prfx_str_elem.appendChild(e);
466 }
467 Element metadata = OAIXML.createElement(OAIXML.METADATA);
468 metadata.appendChild(prfx_str_elem);
469 return metadata;
470 }
471 /** create a header element used when processing requests like ListRecords/GetRecord/ListIdentifiers
472 */
473 private Element createHeaderElement(String oid, String lastmodified) {
474 Element header = OAIXML.createElement(OAIXML.HEADER);
475 Element identifier = OAIXML.createElement(OAIXML.IDENTIFIER);
476 GSXML.setNodeText(identifier, site_name + ":" + coll_name + ":" + oid);
477 header.appendChild(identifier);
478 Element set_spec = OAIXML.createElement(OAIXML.SET_SPEC);
479 GSXML.setNodeText(set_spec, site_name + ":" + coll_name);
480 header.appendChild(set_spec);
481 Element datestamp = OAIXML.createElement(OAIXML.DATESTAMP);
482 GSXML.setNodeText(datestamp, lastmodified);
483 header.appendChild(datestamp);
484 return header;
485 }
486 /** return the metadata information */
487 protected Element processListMetadataFormats(Element req) {
488 // the request sent here must contain an OID. see doListMetadataFormats() in OAIReceptionist
489 Element param = GSXML.getNamedElement(req, OAIXML.PARAM, OAIXML.NAME, OAIXML.OID);
490 if (param == null) {
491 logger.error("An element containing the OID attribute not is present.");
492 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
493 }
494 String oid = param.getAttribute(OAIXML.VALUE);
495 if (oid == null || oid.equals("")) {
496 logger.error("No OID is present in the request.");
497 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
498 }
499 ArrayList oid_list = getChildrenIds(OAIXML.BROWSELIST);
500 if (oid_list == null || oid_list.contains(oid) == false) {
501 logger.error("OID: " + oid + " is not present in the database.");
502 Element e= OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.ID_DOES_NOT_EXIST, ""));
503// logger.error((new XMLConverter()).getPrettyString (e));
504 return e;
505 }
506
507 DBInfo info = null;
508 info = this.gdbm_src.getInfo(oid);
509 if (info == null) { //just double check
510 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.OAI_SERVICE_UNAVAILABLE, ""));
511 }
512
513 NodeList meta_list = getMetadataFormatList(this.coll_config_xml);
514 if (meta_list == null || meta_list.getLength() == 0) {
515 logger.error("No metadata format is present in collectionConfig.xml");
516 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
517 }
518
519 Element list_metadata_formats = OAIXML.createElement(OAIXML.LIST_METADATA_FORMATS);
520 boolean has_meta_format = false;
521
522 for (int i=0; i<meta_list.getLength(); i++) {
523 Element metadata_format = (Element)meta_list.item(i);
524 String[] metadata_names = getMetadataNames(metadata_format);
525 if (containsMetadata(info, metadata_names) == true) {
526 has_meta_format = true;
527 Element meta_fmt = OAIXML.createElement(OAIXML.METADATA_FORMAT);
528 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_PREFIX);
529 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.METADATA_NAMESPACE);
530 OAIXML.copyElement(meta_fmt, metadata_format, OAIXML.SCHEMA);
531 list_metadata_formats.appendChild(meta_fmt);
532 }
533 }//end of for loop
534 if (has_meta_format == false) {
535 logger.error("Specified metadata names are not contained in the database.");
536 return OAIXML.getResponse(OAIXML.createErrorElement(OAIXML.NO_METADATA_FORMATS, ""));
537 } else {
538 return OAIXML.getResponse(list_metadata_formats);
539 }
540 }
541
542 /** return the ListMetadataFormats element in collectionConfig.xml
543 * Currently, it will only contain one metadata format: oai_dc
544 */
545 protected NodeList getMetadataFormatList(Element coll_config_xml) {
546 Element oai_elem = (Element)GSXML.getChildByTagName(coll_config_xml, OAIXML.OAI);
547 Element list_meta_formats = (Element)GSXML.getChildByTagName(oai_elem, OAIXML.LIST_METADATA_FORMATS);
548 return GSXML.getChildrenByTagName(list_meta_formats, OAIXML.METADATA_FORMAT);
549 }
550 /** @param metadata_format - the metadataFormat element in collectionConfig.xml
551 */
552 protected String[] getMetadataNames(Element metadata_format) {
553 String[] names = null;
554
555 //read the mappingList element
556 Element mapping_list = (Element)GSXML.getChildByTagName(metadata_format, OAIXML.MAPPING_LIST);
557 if (mapping_list == null) {
558 logger.info("No metadata mappings are provided in collectionConfig.xml. Use the standard Dublin Core names.");
559 names = OAIXML.getGlobalMetadataMapping(metadata_format.getAttribute(OAIXML.METADATA_PREFIX));
560
561 return (names != null)? names : OAIXML.getDublinCoreNames();
562 }
563 NodeList mappings = GSXML.getChildrenByTagName(mapping_list, OAIXML.MAPPING);
564 int size = mappings.getLength();
565 if (size == 0) {
566 logger.info("No metadata mappings are provided in collectionConfig.xml. \n Return standard DC names.");
567 // read the standard Dublin Core metadata names
568 return OAIXML.getDublinCoreNames();
569 }
570 names = new String[size];
571 for (int i=0; i<size; i++) {
572 names[i] = GSXML.getNodeText((Element)mappings.item(i)).trim();
573 }
574 return names;
575 }
576
577 /** returns a list of the child ids in order, null if no children */
578 protected ArrayList getChildrenIds(String node_id) {
579 DBInfo info = this.gdbm_src.getInfo(node_id);
580 if (info == null) {
581 return null;
582 }
583
584 String contains = info.getInfo("contains");
585 if (contains.equals("")) {
586 return null;
587 }
588 ArrayList children = new ArrayList();
589 StringTokenizer st = new StringTokenizer(contains, ";");
590 while (st.hasMoreTokens()) {
591 String child_id = st.nextToken().replaceAll("\"", node_id);
592 children.add(child_id);
593 }
594 return children;
595 }
596 /**method to check whether any of the 'metadata_names' is contained in the 'info'.
597 * The name may be in the form: <name>,<mapped name>, in which the mapped name is
598 * optional. The mapped name is looked up in the DBInfo; if not present, use the first
599 * name which is mendatory.
600 */
601 protected boolean containsMetadata(DBInfo info, String[] metadata_names) {
602 if (metadata_names == null) return false;
603 logger.info("checking metadata names in db.");
604 for(int i=0; i<metadata_names.length; i++) {
605 int index = metadata_names[i].indexOf(",");
606 String meta_name = (index == -1) ? metadata_names[i] :
607 metadata_names[i].substring(index + 1);
608
609 if(info.getInfo(meta_name).equals("") == false) {
610 return true;
611 }
612 }
613 return false;
614 }
615 /** @param keys - contains a list of keys in string format.
616 * Here is a typical record in the gdbm database, 'keys' contains the values in <...>:
617 *----------------------------------------------------------------------
618[HASH01a84acb0f1aad2380493b3a]
619<doctype>doc
620<hastxt>1
621<Language>en
622<Encoding>windows_1252
623<Plugin>HTMLPlug
624<FileSize>205093
625<Source>wb34te.htm
626<hascover>1
627<dls.Organization>World Bank
628<dls.Title>Development in practice: Toward Gender Equality (wb34te)
629<dls.Language>English
630<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
631<dls.Subject>Women, gender and development, women's organizations
632<dls.Keyword>achieve gender equality
633<URL>http://wb34te/wb34te.htm
634<Title>Development in practice: Toward Gender Equality
635<lastmodified>1178245194
636<assocfilepath>HASH01a8.dir
637<memberof>CL3
638<archivedir>HASH01a8.dir
639<thistype>VList
640<childtype>VList
641<contains>".1;".2;".3;".4;".5;".6;".7;".8;".9
642<docnum>349
643----------------------------------------------------------------------
644 */
645 public String[] getMetadata(DBInfo info, String names) {
646 String[] name_value = new String[2];
647 ArrayList keys = new ArrayList(info.getKeys());
648 for (int i=0; i<keys.size(); i++) {
649 String key = (String)keys.get(i);
650 String first_name = "";
651 String second_name = "";
652 int index = names.indexOf(",");
653 if(index != -1) {
654 first_name = names.substring(0, index);
655 second_name = names.substring(index + 1);
656 } else {
657 first_name = second_name = names;
658 }
659 if(key.equals(second_name)) {
660 String meta_value = info.getInfo(key);
661 name_value[0] = first_name;
662 name_value[1] = meta_value;
663 return name_value;
664 }
665 }
666 return null;
667 }
668 protected HashMap getInfoByNames(DBInfo info, String[] metadata_names) {
669 HashMap map = new HashMap();
670 boolean empty_map = true;
671
672 for(int i=0; i<metadata_names.length; i++) {
673 String[] name_value = getMetadata(info, metadata_names[i]);
674 if(name_value != null) {
675 map.put(name_value[0], name_value[1]);
676 empty_map = false;
677 }
678 }
679 return (empty_map == true) ? null : map;
680 }
681}
682
683
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