source: greenstone3/trunk/src/java/org/greenstone/gsdl3/action/QueryAction.java@ 20292

Last change on this file since 20292 was 20292, checked in by kjdon, 15 years ago

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