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1
22
23 package org.xquark.extractor.runtime;
24
25
26 import java.io.Writer  ;
27 import java.util.List ;
28
29 import org.w3c.dom.Document ;
30 import org.xml.sax.ContentHandler ;
31 import org.xml.sax.ErrorHandler ;
32 import org.xml.sax.SAXException ;
33 import org.xml.sax.ext.LexicalHandler ;
34 import org.xquark.schema.validation.PSVInfoSetProvider;
35 import org.xquark.xml.xdbc.*;
36
37 public class XResultSetUnion implements XMLResultSet {
38 private static final String RCSRevision = "$Revision: 1.2 $";
39 private static final String RCSName = "$Name: $";
40
41 protected ContentHandler _contentHandler = null;
42 protected LexicalHandler _lexicalhandler = null;
43 protected ErrorHandler _errorhandler = null;
44
45 private List _cExprList = null;
46 private XMLStatementInternal _statement = null;
47
48 private int _currentQueryIndex = 0;
49 private XMLResultSet _currenResultSet = null;
50
51 private int _positionAccumulater = 0;
52
53 public XResultSetUnion(List compiledExprList, XMLStatementInternal statement) throws XMLDBCException{
54 setExpressionList(compiledExprList);
55 setStatement(statement);
56 }
57
58 public void setExpressionList(List compiledExprList) {
59 _cExprList = compiledExprList;
60 }
61
62 public void setStatement(XMLStatementInternal statement) {
63 _statement = statement;
64 }
65
66 public XMLStatement getStatement() {
67 return _statement;
68 }
69
70 protected XMLResultSet evaluate(int queryIndex) throws XMLDBCException {
71 return _statement.runQuery((Query.CompiledExpression)_cExprList.get(queryIndex));
72 }
73
74
75
78 public void setContentHandler(ContentHandler contentHandler) {
79 if (contentHandler == null)
80 throw new NullPointerException ("ContentHandler cannot be null.");
81 _contentHandler = contentHandler;
82 }
83
84
87 public void setLexicalHandler(LexicalHandler lexicalhandler) {
88 if (lexicalhandler == null)
89 throw new NullPointerException ("LexicalHandler cannot be null.");
90 _lexicalhandler = lexicalhandler;
91 }
92
93
96 public void setErrorHandler(ErrorHandler errorhandler) {
97 if (errorhandler == null)
99 throw new NullPointerException ("ErrorHandler cannot be null.");
100 _errorhandler = errorhandler;
101 }
102
103
106 public ContentHandler getContentHandler() {
107 return _contentHandler;
108 }
109
110
113 public LexicalHandler getLexicalHandler() {
114 return _lexicalhandler;
115 }
116
117
120 public ErrorHandler getErrorHandler() {
121 return _errorhandler;
122 }
123
124 private void setHandlers(XMLResultSet resultSet) {
125 if (null !=_contentHandler ) resultSet.setContentHandler(_contentHandler);
126 if (null !=_lexicalhandler ) resultSet.setLexicalHandler(_lexicalhandler);
127 if (null !=_errorhandler ) resultSet.setErrorHandler(_errorhandler);
128 }
129
130
131
134 public void close() throws XMLDBCException {
135 if (_currenResultSet != null) {
136 _currenResultSet.close();
137 _currenResultSet = null;
138 }
139 }
140
141
142
143
146 public boolean isBeforeFirst() throws XMLDBCException {
147 return 0 == _positionAccumulater + _currenResultSet.getPosition() ? true : false;
148 }
149
150
153 public Document nextAsDocument() throws XMLDBCException {
154 return _currenResultSet.nextAsDocument();
155 }
156
157
158 public org.w3c.dom.Node nextAsDOM() throws XMLDBCException {
159 return _currenResultSet.nextAsDOM();
160 }
161
162 public void nextAsDOM(org.w3c.dom.Element parent) throws XMLDBCException {
163 _currenResultSet.nextAsDOM(parent);
164 }
165
166
169 public String nextAsString() throws XMLDBCException {
170 return _currenResultSet.nextAsString();
171 }
172
173 public void nextAsStream(Writer out) throws XMLDBCException {
174 _currenResultSet.nextAsStream(out);
175 }
176
177
180 public void nextAsSAX() throws XMLDBCException, SAXException {
181 _currenResultSet.nextAsSAX();
182 }
183
184
187 public boolean hasNext() throws XMLDBCException {
188 boolean retVal = false;
189
190 if (null == _currenResultSet) {
191 _currenResultSet = evaluate(_currentQueryIndex);
192 setHandlers(_currenResultSet);
193 }
194 retVal = _currenResultSet.hasNext();
195 if (!retVal) {
196 int position = _currenResultSet.getPosition();
197 _currenResultSet.close();
198 if (_currentQueryIndex < _cExprList.size() - 1 ) {
199 do {
200 _currentQueryIndex++;
201 _currenResultSet = evaluate(_currentQueryIndex);
202 }
203 while ((!_currenResultSet.hasNext()) && (_currentQueryIndex < _cExprList.size() - 1));
204 retVal = _currenResultSet.hasNext();
205 if (retVal)
206 setHandlers(_currenResultSet);
207
208 _positionAccumulater += position;
209 }
210 }
211 return retVal;
212 }
213
214
217 public int getPosition() throws XMLDBCException {
218 int retVal = _currenResultSet.getPosition();
219 retVal = -1 == retVal ? 0 : retVal;
220 retVal = _positionAccumulater + retVal;
221 retVal = 0 == retVal ? 1 : retVal;
222 return retVal;
223 }
224
225
232 public java.util.Map getPrefixMap() throws XMLDBCException {
233 return java.util.Collections.EMPTY_MAP;
234 }
235
236
248 public XMLDocument getFragmentsAsDocument(String namespace, String localName, String qName) throws XMLDBCException {
249 XMLDocument retVal = null;
250 return retVal;
251 }
252
253
260 public XMLDocument getMetaData() throws XMLDBCException {
261 return null;
262 }
263 public boolean hasRootTag() {
264 return false;
265 }
266
267 public boolean isDocument() {
268 return false;
269 }
270
271 public PSVInfoSetProvider getPSVInfoSetProvider() {
272 return null;
273 }
274
275 }
276 |
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