source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/QueryAction.java@ 31774

Last change on this file since 31774 was 31774, checked in by kjdon, 7 years ago

added a bit of checking for null elements
  • Property svn:keywords set to Author Date Id Revision
File size: 15.4 KB
Line 
1package org.greenstone.gsdl3.action;
2
3import java.io.Serializable;
4import java.util.HashMap;
5import java.util.HashSet;
6
7import org.apache.log4j.Logger;
8import org.greenstone.gsdl3.util.GSParams;
9import org.greenstone.gsdl3.util.GSPath;
10import org.greenstone.gsdl3.util.GSXML;
11import org.greenstone.gsdl3.util.GSXSLT;
12import org.greenstone.gsdl3.util.UserContext;
13import org.greenstone.gsdl3.util.XMLConverter;
14import org.w3c.dom.Document;
15import org.w3c.dom.Element;
16import org.w3c.dom.Node;
17import org.w3c.dom.NodeList;
18
19/** action class for queries */
20public class QueryAction extends Action
21{
22
23 public static final String HITS_PER_PAGE = "hitsPerPage";
24 static Logger logger = Logger.getLogger(org.greenstone.gsdl3.action.QueryAction.class.getName());
25
26 /**
27 * process - processes a request.
28 */
29 public Node process(Node message_node)
30 {
31 Element message = GSXML.nodeToElement(message_node);
32 Document doc = message.getOwnerDocument();
33
34 // get the request - assume there is only one
35 Element request = (Element) GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
36
37 // create the return message
38 Element result = doc.createElement(GSXML.MESSAGE_ELEM);
39 Element response = basicQuery(request);
40 result.appendChild(doc.importNode(response, true));
41 return result;
42 }
43
44 /**
45 * a generic query handler this gets the service description, does the query
46 * (just passes all the params to the service, then gets the titles for any
47 * results
48 */
49 protected Element basicQuery(Element request)
50 {
51 // the result
52 Document doc = request.getOwnerDocument();
53 Element page_response = doc.createElement(GSXML.RESPONSE_ELEM);
54
55 // extract the params from the cgi-request, and check that we have a coll specified
56 Element cgi_param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
57 HashMap<String, Serializable> params = GSXML.extractParams(cgi_param_list, false);
58
59 String request_type = (String) params.get(GSParams.REQUEST_TYPE);
60 String service_name = (String) params.get(GSParams.SERVICE);
61 String collection = (String) params.get(GSParams.COLLECTION);
62 String lang = request.getAttribute(GSXML.LANG_ATT);
63 // collection may be null or empty when we are doing cross coll services
64 if (collection == null || collection.equals(""))
65 {
66 collection = null;
67 }
68
69 UserContext userContext = new UserContext(request);
70 String to = service_name;
71 if (collection != null)
72 {
73 to = GSPath.prependLink(to, collection);
74 }
75
76 // get the format info - there may be global format info in the collection that searching needs
77 Element format_elem = getFormatInfo(to, userContext);
78 if (format_elem != null) {
79 // set the format type
80 format_elem.setAttribute(GSXML.TYPE_ATT, "search");
81 // for now just add to the response
82 page_response.appendChild(doc.importNode(format_elem, true));
83 }
84 // get the service description
85 // we have been asked for the service description
86 Element mr_info_message = doc.createElement(GSXML.MESSAGE_ELEM);
87 Element mr_info_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, to, userContext);
88 mr_info_message.appendChild(mr_info_request);
89
90 // process the message
91 Element mr_info_response = (Element) this.mr.process(mr_info_message);
92
93 boolean does_paging = false;
94
95 // the response
96 Element service_response = (Element) GSXML.getChildByTagName(mr_info_response, GSXML.RESPONSE_ELEM);
97
98 Element service_description = (Element)GSXML.getChildByTagName(service_response, GSXML.SERVICE_ELEM);
99 if (service_description != null) {
100 service_description = (Element) doc.importNode(service_description, true);
101
102 Element meta_list =(Element) GSXML.getChildByTagName(service_description, GSXML.METADATA_ELEM+GSXML.LIST_MODIFIER);
103 if (meta_list != null) {
104 String value = GSXML.getMetadataValue(meta_list, "does_paging");
105 if (value.equals("true")) {
106 does_paging = true;
107 }
108 }
109
110 if (does_paging == false) {
111 // we will do the paging, so lets add in a hitsPerPage param to the service
112 addHitsParamToService(doc, service_description, lang);
113 }
114 }
115 //Element service_description = (Element) doc.importNode(GSXML.getChildByTagName(service_response, GSXML.SERVICE_ELEM), true);
116
117
118 // have we been asked to return the service description
119 // as part of the response?
120 if (request_type.indexOf("d") != -1) {
121 if (service_description != null) {
122 page_response.appendChild(service_description);
123 }
124 addCollectionsHierarchy(page_response,userContext);
125 }
126
127 if (request_type.indexOf("r") == -1)
128 {
129 // just a display request, no actual processing to do
130 //append site metadata
131 addSiteMetadata(page_response, userContext);
132 addInterfaceOptions(page_response);
133 return page_response;
134 }
135
136 // check that we have some service params
137 HashMap service_params = (HashMap) params.get("s1");
138 if (service_params == null)
139 { // no query
140 //append site metadata
141 addSiteMetadata(page_response, userContext);
142 addInterfaceOptions(page_response);
143 return page_response;
144 }
145
146 // create the query request
147 Element mr_query_message = doc.createElement(GSXML.MESSAGE_ELEM);
148 Element mr_query_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_PROCESS, to, userContext);
149 mr_query_message.appendChild(mr_query_request);
150
151 Element query_param_list = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
152 GSXML.addParametersToList(query_param_list, service_params);
153 mr_query_request.appendChild(query_param_list);
154
155 // do the query
156 Element mr_query_response = (Element) this.mr.process(mr_query_message);
157
158 // check for errors
159 if (processErrorElements(mr_query_response, page_response))
160 {
161 //append site metadata
162 addSiteMetadata(page_response, userContext);
163 addInterfaceOptions(page_response);
164 return page_response;
165 }
166
167 Element query_response = (Element) GSXML.getChildByTagName(mr_query_response, GSXML.RESPONSE_ELEM);
168 Element query_result_metadata_list = (Element) GSXML.getChildByTagName(query_response, GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
169
170 if (query_result_metadata_list == null)
171 {
172 logger.error("No query result metadata.\n");
173 }
174 else
175 { // add it into the page response
176 page_response.appendChild(doc.importNode(query_result_metadata_list, true));
177 }
178
179 Element query_term_info_list = (Element) GSXML.getChildByTagName(query_response, GSXML.TERM_ELEM + GSXML.LIST_MODIFIER);
180 if (query_term_info_list == null)
181 {
182 logger.error("No query term information.\n");
183 }
184 else
185 { // add it into the page response
186 page_response.appendChild(doc.importNode(query_term_info_list, true));
187 }
188
189 Element facet_list = (Element) GSXML.getChildByTagName(query_response, GSXML.FACET_ELEM + GSXML.LIST_MODIFIER);
190 if (facet_list == null)
191 {
192 logger.error("No query term information.\n");
193 }
194 else
195 { // add it into the page response
196 page_response.appendChild(doc.importNode(facet_list, true));
197 }
198
199 // check that there are some documents - for now check the list, but later should use a numdocs metadata elem
200 Element document_list = (Element) GSXML.getChildByTagName(query_response, GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
201 // documentList not present if no docs found
202 if (document_list == null)
203 {
204 // add in a dummy doc node list - used by the display. need to think about this
205 page_response.appendChild(doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER));
206 //append site metadata
207 addSiteMetadata(page_response, userContext);
208 addInterfaceOptions(page_response);
209 return page_response;
210 }
211
212 // now we check to see if there is metadata already - some search services return predefined metadata. if there is some, don't do a metadata request
213 NodeList doc_metadata = document_list.getElementsByTagName(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
214 if (doc_metadata.getLength() > 0)
215 {
216 // why are we not paging these results?????
217 // append the doc list to the result
218 page_response.appendChild(doc.importNode(document_list, true));
219 //append site metadata
220 addSiteMetadata(page_response, userContext);
221 addInterfaceOptions(page_response);
222 return page_response;
223 }
224
225 // get the metadata elements needed from the format statement if any
226 HashSet<String> metadata_names = new HashSet<String>();
227 metadata_names.add("Title");
228 // we already got the format element earlier
229 if (format_elem != null)
230 {
231 getRequiredMetadataNames(format_elem, metadata_names);
232 }
233
234 // paging of the results is done here - we filter the list to remove unwanted entries before retrieving metadata
235 Element filtered_doc_list;
236 if (does_paging) {
237 filtered_doc_list = (Element)doc.importNode(document_list, true);
238 } else {
239 filtered_doc_list = filterDocList(doc, params, service_params, document_list);
240 }
241 // do the metadata request on the filtered list
242 Element mr_metadata_message = doc.createElement(GSXML.MESSAGE_ELEM);
243 to = "DocumentMetadataRetrieve";
244 if (collection != null)
245 {
246 to = GSPath.prependLink(to, collection);
247 }
248 Element mr_metadata_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_PROCESS, to, userContext);
249 mr_metadata_message.appendChild(mr_metadata_request);
250
251 // just get all for now - the receptionist should perhaps pass in some
252 // metadata that it wants, and QueryAction should look through the format stuff to see if there is any other?
253
254 Element extraMetaListElem = (Element) GSXML.getChildByTagName(request, GSXML.EXTRA_METADATA + GSXML.LIST_MODIFIER);
255 if(extraMetaListElem != null)
256 {
257 NodeList extraMetaList = extraMetaListElem.getElementsByTagName(GSXML.EXTRA_METADATA);
258 for(int i = 0; i < extraMetaList.getLength(); i++)
259 {
260 metadata_names.add(((Element)extraMetaList.item(i)).getAttribute(GSXML.NAME_ATT));
261 }
262 }
263
264 Element dm_param_list = createMetadataParamList(doc,metadata_names);
265
266 mr_metadata_request.appendChild(dm_param_list);
267
268 // add in the doc node list too
269 mr_metadata_request.appendChild(filtered_doc_list);
270
271 Element mr_metadata_response = (Element) this.mr.process(mr_metadata_message);
272
273 Element query_result_snippet_list = (Element) GSXML.getChildByTagName(query_response, GSXML.HL_SNIPPET_ELEM + GSXML.LIST_MODIFIER);
274
275 // check for errors
276 processErrorElements(mr_metadata_response, page_response);
277
278 Element metadata_response = (Element) GSXML.getChildByTagName(mr_metadata_response, GSXML.RESPONSE_ELEM);
279
280 Element query_result_document_list = (Element) GSXML.getChildByTagName(metadata_response, GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
281
282 if (query_result_document_list != null)
283 {
284 page_response.appendChild(doc.importNode(query_result_document_list, true));
285 if (query_result_snippet_list != null)
286 {
287 page_response.appendChild(doc.importNode(query_result_snippet_list,true));
288 }
289 }
290
291 //logger.debug("Query page:\n" + this.converter.getPrettyString(page_response));
292 //append site metadata
293 addSiteMetadata(page_response, userContext);
294 addInterfaceOptions(page_response);
295 return page_response;
296 }
297
298 private void addCollectionsHierarchy(Element page_response, UserContext userContext) {
299 Document doc = page_response.getOwnerDocument();
300 String collectionsHierarchy = "CollectionsHierarchy";
301 if (checkServiceAvailable(userContext, collectionsHierarchy)){
302 Element groupQueryMessage = doc.createElement(GSXML.MESSAGE_ELEM);
303 Element groupQueryRequest = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_PROCESS, collectionsHierarchy, userContext);
304 groupQueryMessage.appendChild(groupQueryRequest);
305 Element groupQueryResult = (Element) this.mr.process(groupQueryMessage);
306 if (groupQueryResult == null){
307 return;
308 }
309 Element groupQueryResponse = (Element) GSXML.getChildByTagName(groupQueryResult, GSXML.RESPONSE_ELEM);
310 if (groupQueryResponse == null){
311 return;
312 }
313 Element hierarchy = (Element) GSXML.getChildByTagName(groupQueryResponse, GSXML.HIERARCHY_ELEM);
314 page_response.appendChild(doc.importNode(hierarchy, true));
315 }
316
317
318 }
319
320 private boolean checkServiceAvailable(UserContext userContext, String collectionsHierarchy) {
321
322 Document doc = XMLConverter.newDOM();
323 Element infoMessage = doc.createElement(GSXML.MESSAGE_ELEM);
324 Element infoRequest = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, "", userContext);
325 Element paramList = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
326 infoRequest.appendChild(paramList);
327 GSXML.addParameterToList(paramList, GSXML.SUBSET_PARAM, GSXML.SERVICE_ELEM + GSXML.LIST_MODIFIER);
328 infoMessage.appendChild(infoRequest);
329 Element responseMessage = (Element) this.mr.process(infoMessage);
330 if (responseMessage == null)
331 {
332 logger.error("couldn't query the message router!");
333 return false;
334 }
335 NodeList serviceLists = responseMessage.getElementsByTagName(GSXML.SERVICE_ELEM + GSXML.LIST_MODIFIER);
336 if (serviceLists == null || serviceLists.getLength() == 0){
337 logger.error("No service List in response message from message router!");
338 return false;
339 }
340 Element serviceList = (Element) serviceLists.item(0);
341 Element groupInfoService = GSXML.getNamedElement(serviceList, GSXML.SERVICE_ELEM, GSXML.NAME_ATT, collectionsHierarchy);
342 if (groupInfoService == null){
343 logger.error("service " + collectionsHierarchy + " unavailable");
344 return false;
345 }
346 return true;
347 }
348
349 /** this filters out some of the doc results for result paging */
350 protected Element filterDocList(Document doc, HashMap<String, Serializable> params, HashMap service_params, Element orig_doc_list)
351 {
352
353 String hits_pp = (String) service_params.get(HITS_PER_PAGE);
354
355 int hits = 20;
356 if (hits_pp != null && !hits_pp.equals(""))
357 {
358 if (hits_pp.equals("all")) {
359 hits = -1;
360 } else {
361 try
362 {
363 hits = Integer.parseInt(hits_pp);
364 }
365 catch (Exception e)
366 {
367 hits = 20;
368 }
369 }
370 }
371 if (hits == -1)
372 { // all
373 return (Element) doc.importNode(orig_doc_list, true);
374 }
375 NodeList result_docs = orig_doc_list.getElementsByTagName(GSXML.DOC_NODE_ELEM);
376
377 int num_docs = result_docs.getLength();
378 if (num_docs <= hits)
379 {
380 // too few docs to do paging
381 return (Element) doc.importNode(orig_doc_list, true);
382 }
383
384 // now we need our own doc list
385 Element result_list = doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
386
387 String start_p = (String) service_params.get("startPage");
388 if (start_p == null)
389 {
390 start_p = (String) params.get("startPage");
391 }
392
393 int start = 1;
394 if (start_p != null && !start_p.equals(""))
395 {
396 try
397 {
398 start = Integer.parseInt(start_p);
399 }
400 catch (Exception e)
401 {
402 start = 1;
403 }
404 }
405 int start_from = (start - 1) * hits;
406 int end_at = (start * hits) - 1;
407
408 if (start_from > num_docs)
409 {
410 // something has gone wrong
411 return result_list;
412 }
413
414 if (end_at > num_docs)
415 {
416 end_at = num_docs - 1;
417 }
418 // now we finally have the docs numbers to use
419 for (int i = start_from; i <= end_at; i++)
420 {
421 result_list.appendChild(doc.importNode(result_docs.item(i), true));
422 }
423
424 return result_list;
425 }
426
427 protected boolean addHitsParamToService(Document doc, Element service_description, String lang) {
428 Element param_list = (Element)GSXML.getChildByTagName(service_description, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
429 Element param = GSXML.createParameterDescription(doc, HITS_PER_PAGE, getTextString("param." + HITS_PER_PAGE, lang, "ServiceRack", null), GSXML.PARAM_TYPE_INTEGER, "20", null, null);
430 Element query_param = GSXML.getNamedElement(param_list, GSXML.PARAM_ELEM, GSXML.NAME_ATT, "query");
431 if (query_param != null) {
432 param_list.insertBefore(param, query_param);
433 } else {
434 param_list.appendChild(param);
435 }
436 return true;
437 }
438
439}
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