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1
5
6 package org.joseki.server.processors;
7
8
9 import org.joseki.util.* ;
10 import org.joseki.vocabulary.*;
11 import org.joseki.server.* ;
12
13 import com.hp.hpl.jena.rdf.model.* ;
14
15 import com.hp.hpl.jena.rdql.* ;
16
17 import org.apache.commons.logging.* ;
18 import java.util.* ;
19
20
30
31 public class QueryProcessorRDQL extends QueryProcessorCom implements QueryProcessor
32 {
33 static Log logger = LogFactory.getLog(QueryProcessorRDQL.class.getName()) ;
34
35 public QueryProcessorRDQL()
36 {
37 super() ;
38 }
39
40 public String  getInterfaceURI() { return JosekiVocab.queryOperationRDQL ; }
41
42 public Model execQuery(ModelSource src, String queryString, Request request)
43 throws RDFException, QueryExecutionException
44 {
45 if (!(src instanceof ModelSourceJena))
46 throw new QueryExecutionException(
47 ExecutionError.rcOperationNotSupported,
48 "Wrong implementation - this RDQL processor works with Jena models");
49 Model model = ((ModelSourceJena)src).getModel() ;
50 QueryResults results = null ;
51
52 try {
53 if ( queryString == null || queryString.equals("") )
54 {
55 logger.debug("Query: No query string provided") ;
56 }
57 else
58 {
59 String tmp = queryString ;
60 tmp = tmp.replace('\n', ' ') ;
61 tmp = tmp.replace('\r', ' ') ;
62 logger.debug("Query: "+tmp) ;
63 }
64
65 if (queryString == null)
66 throw new QueryExecutionException(
67 ExecutionError.rcQueryExecutionFailure,
68 "No query supplied");
69
70 Query query = null ;
71 try {
72 query = new Query(queryString) ;
73 } catch (Throwable thrown)
74 {
75 logger.info("Query parse error: request failed") ;
76 throw new QueryExecutionException(ExecutionError.rcQueryParseFailure, "Parse error") ;
77 }
78
79 query.setSource(model) ;
80
81 QueryExecution qe = new QueryEngine(query) ;
83
84 results = qe.exec();
85 String format = request.getParam("format");
86 String closure$ = request.getParam("closure");
88 boolean closure = (closure$ != null && closure$.equalsIgnoreCase("true"));
89
90 Model resultModel = ModelFactory.createDefaultModel();
91
92 if (closure)
95 {
96 doClosure(query, results, resultModel);
97 return resultModel;
98 }
99
100 if (format == null)
101 {
102 for (; results.hasNext();)
103 {
104 ResultBinding rb = (ResultBinding)results.next();
105 rb.mergeTriples(resultModel);
106 }
107 resultModel.setNsPrefixes(model);
108 Map m = src.getPrefixes();
109 if (m != null)
110 resultModel.setNsPrefixes(src.getPrefixes());
111
112 return resultModel;
113 }
114
115 if (format.equalsIgnoreCase("BV") || format.equals("http://jena.hpl.hp.com/2003/07/query/BV"))
116 {
117 QueryResultsFormatter qfmt = new QueryResultsFormatter(results);
118 qfmt.asRDF(resultModel);
119 qfmt.close() ;
120 resultModel.setNsPrefix("rs", "http://jena.hpl.hp.com/2003/03/result-set#");
121 return resultModel;
122 }
123
124 throw new QueryExecutionException(
125 ExecutionError.rcOperationNotSupported,
126 "Unknown results format requested: " + format);
127 }
128 catch (QueryException qEx)
129 {
130 logger.info("Query execution error: "+qEx) ;
131 throw new QueryExecutionException(ExecutionError.rcQueryExecutionFailure, null) ;
132 }
133 finally
134 {
135 if ( results != null )
136 results.close() ;
137 }
138 }
139
140 public Model execQuery(ModelSource aModel, Model queryModel, Request request)
141 throws RDFException, QueryExecutionException
142 {
143 Model resultModel = null ;
144 NodeIterator nIter = queryModel.listObjectsOfProperty(JosekiVocab.queryScript) ;
145 for ( ; nIter.hasNext() ; )
146 {
147 RDFNode n = nIter.nextNode() ;
148 if ( n instanceof Literal )
149 {
150 String queryString = ((Literal)n).getString() ;
151 Model m = execQuery(aModel, queryString, request) ;
152 if ( resultModel == null )
153 resultModel = m ;
154 else
155 resultModel.add(m) ;
156 }
157 }
158 return resultModel ;
159 }
160
161 private void doClosure(Query query, QueryResults results, Model resultModel)
162 {
163 for (; results.hasNext() ; )
164 {
165 ResultBinding rb = (ResultBinding)results.next() ;
166 for ( Iterator iter = query.getResultVars().iterator() ; iter.hasNext() ; )
167 {
168 String var = (String )iter.next() ;
169 Object x = rb.get(var) ;
170 if ( ! ( x instanceof Resource ) )
171 {
172 logger.warn("Non-resource in query closure: "+x) ;
173 continue ;
174 }
175 Closure.closure((Resource)x, false, resultModel) ;
176 }
177 }
178 }
179
180 }
181
182
208 |
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