source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/QueryAction.java@ 24993

Last change on this file since 24993 was 24993, checked in by sjm84, 12 years ago

Adding UserContext to replace the use of lang and uid
  • Property svn:keywords set to Author Date Id Revision
File size: 10.6 KB
Line 
1package org.greenstone.gsdl3.action;
2
3import org.greenstone.gsdl3.core.ModuleInterface;
4import org.greenstone.gsdl3.util.*;
5// XML classes
6import org.w3c.dom.Node;
7import org.w3c.dom.NodeList;
8import org.w3c.dom.Text;
9import org.w3c.dom.Document;
10import org.w3c.dom.Element;
11
12import java.util.HashMap;
13import java.util.HashSet;
14import java.util.Vector;
15import java.util.Map;
16import java.util.Iterator;
17import java.io.File;
18
19import org.apache.log4j.*;
20
21/** action class for queries */
22public class QueryAction extends Action
23{
24
25 static Logger logger = Logger.getLogger(org.greenstone.gsdl3.action.QueryAction.class.getName());
26
27 /**
28 * process - processes a request.
29 */
30 public Node process(Node message_node)
31 {
32
33 Element message = this.converter.nodeToElement(message_node);
34
35 // get the request - assume there is only one
36 Element request = (Element) GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
37
38 // create the return message
39 Element result = this.doc.createElement(GSXML.MESSAGE_ELEM);
40 Element response = basicQuery(request);
41 result.appendChild(this.doc.importNode(response, true));
42 return result;
43 }
44
45 /**
46 * a generic query handler this gets the service description, does the query
47 * (just passes all the params to the service, then gets the titles for any
48 * results
49 */
50 protected Element basicQuery(Element request)
51 {
52
53 // the result
54 Element page_response = this.doc.createElement(GSXML.RESPONSE_ELEM);
55
56 // extract the params from the cgi-request, and check that we have a coll specified
57 Element cgi_param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
58 HashMap params = GSXML.extractParams(cgi_param_list, false);
59
60 String request_type = (String) params.get(GSParams.REQUEST_TYPE);
61 String service_name = (String) params.get(GSParams.SERVICE);
62 String collection = (String) params.get(GSParams.COLLECTION);
63
64 // collection may be null or empty when we are doing cross coll services
65 if (collection == null || collection.equals(""))
66 {
67 collection = null;
68 }
69
70 UserContext userContext = new UserContext(request);
71 String to = service_name;
72 if (collection != null)
73 {
74 to = GSPath.prependLink(to, collection);
75 }
76
77 if (request_type.indexOf("d") != -1)
78 {
79 // we have been asked for the service description
80 Element mr_info_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
81 Element mr_info_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_DESCRIBE, to, userContext);
82 mr_info_message.appendChild(mr_info_request);
83
84 // process the message
85 Element mr_info_response = (Element) this.mr.process(mr_info_message);
86 // the response
87
88 Element service_response = (Element) GSXML.getChildByTagName(mr_info_response, GSXML.RESPONSE_ELEM);
89
90 Element service_description = (Element) this.doc.importNode(GSXML.getChildByTagName(service_response, GSXML.SERVICE_ELEM), true);
91 page_response.appendChild(service_description);
92 }
93
94 if (request_type.indexOf("r") == -1)
95 {
96 // just a display request, no actual processing to do
97 //append site metadata
98 addSiteMetadata(page_response, userContext);
99 return page_response;
100 }
101
102 // check that we have some service params
103 HashMap service_params = (HashMap) params.get("s1");
104 if (service_params == null)
105 { // no query
106 //append site metadata
107 addSiteMetadata(page_response, userContext);
108 return page_response;
109 }
110
111 // create the query request
112 Element mr_query_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
113 Element mr_query_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, to, userContext);
114 mr_query_message.appendChild(mr_query_request);
115
116 Element query_param_list = this.doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
117 GSXML.addParametersToList(this.doc, query_param_list, service_params);
118 mr_query_request.appendChild(query_param_list);
119
120 // also get the format stuff now if there is some
121 Element format_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_FORMAT, to, userContext);
122 mr_query_message.appendChild(format_request);
123
124 logger.debug(GSXML.xmlNodeToString(mr_query_message, false));
125
126 // do the query
127 Element mr_query_response = (Element) this.mr.process(mr_query_message);
128
129 // check for errors
130 if (processErrorElements(mr_query_response, page_response))
131 {
132 //append site metadata
133 addSiteMetadata(page_response, userContext);
134 return page_response;
135 }
136
137 NodeList responses = mr_query_response.getElementsByTagName(GSXML.RESPONSE_ELEM);
138 Element query_response = (Element) responses.item(0);
139 Element format_response = (Element) responses.item(1);
140
141 Element query_result_metadata_list = (Element) GSXML.getChildByTagName(query_response, GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
142 if (query_result_metadata_list == null)
143 {
144 logger.error("No query result metadata.\n");
145 }
146 else
147 { // add it into the page response
148 page_response.appendChild(this.doc.importNode(query_result_metadata_list, true));
149 }
150
151 Element query_term_info_list = (Element) GSXML.getChildByTagName(query_response, GSXML.TERM_ELEM + GSXML.LIST_MODIFIER);
152 if (query_term_info_list == null)
153 {
154 logger.error("No query term information.\n");
155 }
156 else
157 { // add it into the page response
158 page_response.appendChild(this.doc.importNode(query_term_info_list, true));
159 }
160
161 // check that there are some documents - for now check the list, but later should use a numdocs metadata elem
162 Element document_list = (Element) GSXML.getChildByTagName(query_response, GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
163 // documentList not present if no docs found
164 if (document_list == null)
165 {
166 // add in a dummy doc node list - used by the display. need to think about this
167 page_response.appendChild(this.doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER));
168 //append site metadata
169 addSiteMetadata(page_response, userContext);
170 return page_response;
171 }
172
173 // 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
174 NodeList doc_metadata = document_list.getElementsByTagName(GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
175 if (doc_metadata.getLength() > 0)
176 {
177 logger.error("have already found metadata!");
178 // append the doc list to the result
179 page_response.appendChild(this.doc.importNode(document_list, true));
180 //append site metadata
181 addSiteMetadata(page_response, userContext);
182 return page_response;
183 }
184
185 // get the metadata elements needed from the format statement if any
186 HashSet metadata_names = new HashSet();
187 metadata_names.add("Title");
188 // add in the format info to the stylesheet if there is any
189 Element format_elem = (Element) GSXML.getChildByTagName(format_response, GSXML.FORMAT_ELEM);
190 if (format_elem != null)
191 {
192 // set the format type
193 format_elem.setAttribute(GSXML.TYPE_ATT, "search");
194 // for now just add to the response
195 page_response.appendChild(this.doc.importNode(format_elem, true));
196 getRequiredMetadataNames(format_elem, metadata_names);
197 }
198
199 // paging of the results is done here - we filter the list to remove unwanted entries before retrieving metadata
200 Element filtered_doc_list = filterDocList(params, service_params, document_list);
201
202 // do the metadata request on the filtered list
203 Element mr_metadata_message = this.doc.createElement(GSXML.MESSAGE_ELEM);
204 to = "DocumentMetadataRetrieve";
205 if (collection != null)
206 {
207 to = GSPath.prependLink(to, collection);
208 }
209 Element mr_metadata_request = GSXML.createBasicRequest(this.doc, GSXML.REQUEST_TYPE_PROCESS, to, userContext);
210 mr_metadata_message.appendChild(mr_metadata_request);
211
212 // just get all for now - the receptionist should perhaps pass in some
213 // metadata that it wants, and QueryAction should look through the format stuff to see if there is any other?
214
215 Element dm_param_list = createMetadataParamList(metadata_names);
216
217 mr_metadata_request.appendChild(dm_param_list);
218
219 // add in the doc node list too
220 mr_metadata_request.appendChild(filtered_doc_list);
221
222 Element mr_metadata_response = (Element) this.mr.process(mr_metadata_message);
223 // check for errors
224 processErrorElements(mr_metadata_response, page_response);
225
226 Element metadata_response = (Element) GSXML.getChildByTagName(mr_metadata_response, GSXML.RESPONSE_ELEM);
227
228 Element query_result_document_list = (Element) GSXML.getChildByTagName(metadata_response, GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
229
230 if (query_result_document_list != null)
231 {
232 page_response.appendChild(this.doc.importNode(query_result_document_list, true));
233 }
234
235 logger.debug("Query page:\n" + this.converter.getPrettyString(page_response));
236 //append site metadata
237 addSiteMetadata(page_response, userContext);
238 return page_response;
239 }
240
241 /** this filters out some of the doc results for result paging */
242 protected Element filterDocList(HashMap params, HashMap service_params, Element orig_doc_list)
243 {
244
245 // check the hits_per_page param - is it a service param??
246 String hits_pp = (String) service_params.get("hitsPerPage");
247 if (hits_pp == null)
248 {
249 // the service is doing the paging, so we want to display all of the returned docs(???)
250 // return (Element)this.doc.importNode(orig_doc_list, true);
251 // try hitsPerPage in the globle param
252 hits_pp = (String) params.get("hitsPerPage");
253 }
254
255 int hits = 20;
256 if (hits_pp != null && !hits_pp.equals(""))
257 {
258 try
259 {
260 hits = Integer.parseInt(hits_pp);
261 }
262 catch (Exception e)
263 {
264 hits = 20;
265 }
266 }
267
268 if (hits == -1)
269 { // all
270 return (Element) this.doc.importNode(orig_doc_list, true);
271 }
272 NodeList result_docs = orig_doc_list.getElementsByTagName(GSXML.DOC_NODE_ELEM);
273
274 int num_docs = result_docs.getLength();
275 if (num_docs <= hits)
276 {
277 // too few docs to do paging
278 return (Element) this.doc.importNode(orig_doc_list, true);
279 }
280
281 // now we need our own doc list
282 Element result_list = this.doc.createElement(GSXML.DOC_NODE_ELEM + GSXML.LIST_MODIFIER);
283
284 String start_p = (String) service_params.get("startPage");
285 if (start_p == null)
286 {
287 start_p = (String) params.get("startPage");
288 }
289
290 int start = 1;
291 if (start_p != null && !start_p.equals(""))
292 {
293 try
294 {
295 start = Integer.parseInt(start_p);
296 }
297 catch (Exception e)
298 {
299 start = 1;
300 }
301 }
302
303 int start_from = (start - 1) * hits;
304 int end_at = (start * hits) - 1;
305
306 if (start_from > num_docs)
307 {
308 // something has gone wrong
309 return result_list;
310 }
311
312 if (end_at > num_docs)
313 {
314 end_at = num_docs - 1;
315 }
316
317 // now we finally have the docs numbers to use
318 for (int i = start_from; i <= end_at; i++)
319 {
320 result_list.appendChild(this.doc.importNode(result_docs.item(i), true));
321 }
322
323 return result_list;
324 }
325
326}
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