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package org.jaxen.pattern; |
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|
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import java.util.Iterator; |
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import java.util.List; |
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import java.util.ListIterator; |
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|
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import org.jaxen.JaxenException; |
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import org.jaxen.JaxenHandler; |
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import org.jaxen.expr.DefaultAllNodeStep; |
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import org.jaxen.expr.DefaultCommentNodeStep; |
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import org.jaxen.expr.DefaultFilterExpr; |
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import org.jaxen.expr.DefaultNameStep; |
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import org.jaxen.expr.DefaultProcessingInstructionNodeStep; |
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import org.jaxen.expr.DefaultStep; |
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import org.jaxen.expr.DefaultTextNodeStep; |
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import org.jaxen.expr.DefaultXPathFactory; |
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import org.jaxen.expr.Expr; |
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import org.jaxen.expr.FilterExpr; |
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import org.jaxen.expr.LocationPath; |
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import org.jaxen.expr.Predicate; |
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import org.jaxen.expr.PredicateSet; |
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import org.jaxen.expr.Step; |
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import org.jaxen.expr.UnionExpr; |
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import org.jaxen.saxpath.Axis; |
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import org.jaxen.saxpath.XPathReader; |
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import org.jaxen.saxpath.helpers.XPathReaderFactory; |
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|
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|
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|
83 | 0 | public class PatternParser |
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{ |
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private static final boolean TRACE = false; |
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private static final boolean USE_HANDLER = false; |
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public static Pattern parse(String text) throws JaxenException, org.jaxen.saxpath.SAXPathException |
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{ |
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if ( USE_HANDLER ) |
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{ |
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XPathReader reader = XPathReaderFactory.createReader(); |
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PatternHandler handler = new PatternHandler(); |
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|
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handler.setXPathFactory( new DefaultXPathFactory() ); |
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reader.setXPathHandler( handler ); |
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reader.parse( text ); |
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|
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return handler.getPattern(); |
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} |
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else |
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{ |
102 | 46 | XPathReader reader = XPathReaderFactory.createReader(); |
103 | 46 | JaxenHandler handler = new JaxenHandler(); |
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|
105 | 46 | handler.setXPathFactory( new DefaultXPathFactory() ); |
106 | 46 | reader.setXPathHandler( handler ); |
107 | 46 | reader.parse( text ); |
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|
109 | 46 | Pattern pattern = convertExpr( handler.getXPathExpr().getRootExpr() ); |
110 | 46 | return pattern.simplify(); |
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} |
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} |
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|
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protected static Pattern convertExpr(Expr expr) throws JaxenException |
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{ |
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if ( TRACE ) |
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{ |
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System.out.println( "Converting: " + expr + " into a pattern." ); |
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} |
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|
121 | 58 | if ( expr instanceof LocationPath ) |
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{ |
123 | 52 | return convertExpr( (LocationPath) expr ); |
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} |
125 | 6 | else if ( expr instanceof FilterExpr ) |
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{ |
127 | 0 | LocationPathPattern answer = new LocationPathPattern(); |
128 | 0 | answer.addFilter( (FilterExpr) expr ); |
129 | 0 | return answer; |
130 | |
} |
131 | 6 | else if ( expr instanceof UnionExpr ) |
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{ |
133 | 6 | UnionExpr unionExpr = (UnionExpr) expr; |
134 | 6 | Pattern lhs = convertExpr( unionExpr.getLHS() ); |
135 | 6 | Pattern rhs = convertExpr( unionExpr.getRHS() ); |
136 | 6 | return new UnionPattern( lhs, rhs ); |
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} |
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else |
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{ |
140 | 0 | LocationPathPattern answer = new LocationPathPattern(); |
141 | 0 | answer.addFilter( new DefaultFilterExpr( expr, |
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new PredicateSet()) ); |
143 | 0 | return answer; |
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} |
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} |
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|
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protected static LocationPathPattern convertExpr(LocationPath locationPath) throws JaxenException |
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{ |
149 | 52 | LocationPathPattern answer = new LocationPathPattern(); |
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|
151 | 52 | List steps = locationPath.getSteps(); |
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|
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|
154 | 52 | LocationPathPattern path = answer; |
155 | 52 | boolean first = true; |
156 | 52 | for ( ListIterator iter = steps.listIterator( steps.size() ); iter.hasPrevious(); ) |
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{ |
158 | 72 | Step step = (Step) iter.previous(); |
159 | 72 | if ( first ) |
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{ |
161 | 48 | first = false; |
162 | 48 | path = convertStep( path, step ); |
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} |
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else |
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{ |
166 | 24 | if ( navigationStep( step ) ) |
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{ |
168 | 24 | LocationPathPattern parent = new LocationPathPattern(); |
169 | 24 | int axis = step.getAxis(); |
170 | 24 | if ( axis == Axis.DESCENDANT || axis == Axis.DESCENDANT_OR_SELF ) |
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{ |
172 | 4 | path.setAncestorPattern( parent ); |
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} |
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else |
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{ |
176 | 20 | path.setParentPattern( parent ); |
177 | |
} |
178 | 24 | path = parent; |
179 | |
} |
180 | 24 | path = convertStep( path, step ); |
181 | |
} |
182 | 72 | } |
183 | 52 | if ( locationPath.isAbsolute() ) |
184 | |
{ |
185 | 8 | LocationPathPattern parent = new LocationPathPattern( NodeTypeTest.DOCUMENT_TEST ); |
186 | 8 | path.setParentPattern( parent ); |
187 | |
} |
188 | 52 | return answer; |
189 | |
} |
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|
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protected static LocationPathPattern convertStep(LocationPathPattern path, Step step) throws JaxenException |
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{ |
193 | 72 | if ( step instanceof DefaultAllNodeStep ) |
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{ |
195 | 4 | int axis = step.getAxis(); |
196 | 4 | if ( axis == Axis.ATTRIBUTE ) |
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{ |
198 | 0 | path.setNodeTest( NodeTypeTest.ATTRIBUTE_TEST ); |
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} |
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else |
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{ |
202 | 4 | path.setNodeTest( NodeTypeTest.ELEMENT_TEST ); |
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} |
204 | 4 | } |
205 | 68 | else if ( step instanceof DefaultCommentNodeStep ) |
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{ |
207 | 0 | path.setNodeTest( NodeTypeTest.COMMENT_TEST ); |
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} |
209 | 68 | else if ( step instanceof DefaultProcessingInstructionNodeStep ) |
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{ |
211 | 0 | path.setNodeTest( NodeTypeTest.PROCESSING_INSTRUCTION_TEST ); |
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} |
213 | 68 | else if ( step instanceof DefaultTextNodeStep ) |
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{ |
215 | 4 | path.setNodeTest( TextNodeTest.SINGLETON ); |
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} |
217 | 64 | else if ( step instanceof DefaultCommentNodeStep ) |
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{ |
219 | 0 | path.setNodeTest( NodeTypeTest.COMMENT_TEST ); |
220 | |
} |
221 | 64 | else if ( step instanceof DefaultNameStep ) |
222 | |
{ |
223 | 64 | DefaultNameStep nameStep = (DefaultNameStep) step; |
224 | 64 | String localName = nameStep.getLocalName(); |
225 | 64 | String prefix = nameStep.getPrefix(); |
226 | 64 | int axis = nameStep.getAxis(); |
227 | 64 | short nodeType = Pattern.ELEMENT_NODE; |
228 | 64 | if ( axis == Axis.ATTRIBUTE ) |
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{ |
230 | 4 | nodeType = Pattern.ATTRIBUTE_NODE; |
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} |
232 | 64 | if ( nameStep.isMatchesAnyName() ) |
233 | |
{ |
234 | 16 | if ( prefix.length() == 0 || prefix.equals( "*" ) ) |
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{ |
236 | 14 | if ( axis == Axis.ATTRIBUTE ) |
237 | |
{ |
238 | 4 | path.setNodeTest( NodeTypeTest.ATTRIBUTE_TEST ); |
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} |
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else |
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{ |
242 | 10 | path.setNodeTest( NodeTypeTest.ELEMENT_TEST ); |
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} |
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} |
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else |
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{ |
247 | 2 | path.setNodeTest( new NamespaceTest( prefix, nodeType ) ); |
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} |
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} |
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else |
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{ |
252 | 48 | path.setNodeTest( new NameTest( localName, nodeType ) ); |
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|
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} |
255 | 64 | return convertDefaultStep(path, nameStep); |
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} |
257 | 0 | else if ( step instanceof DefaultStep ) |
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{ |
259 | 0 | return convertDefaultStep(path, (DefaultStep) step); |
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} |
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else |
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{ |
263 | 0 | throw new JaxenException( "Cannot convert: " + step + " to a Pattern" ); |
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} |
265 | 8 | return path; |
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} |
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|
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protected static LocationPathPattern convertDefaultStep(LocationPathPattern path, DefaultStep step) throws JaxenException |
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{ |
270 | 64 | List predicates = step.getPredicates(); |
271 | 64 | if ( ! predicates.isEmpty() ) |
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{ |
273 | 10 | FilterExpr filter = new DefaultFilterExpr(new PredicateSet()); |
274 | 10 | for ( Iterator iter = predicates.iterator(); iter.hasNext(); ) |
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{ |
276 | 10 | filter.addPredicate( (Predicate) iter.next() ); |
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} |
278 | 10 | path.addFilter( filter ); |
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} |
280 | 64 | return path; |
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} |
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|
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protected static boolean navigationStep( Step step ) |
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{ |
285 | 24 | if ( step instanceof DefaultNameStep ) |
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{ |
287 | 20 | return true; |
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} |
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else |
290 | 6 | if ( step.getClass().equals( DefaultStep.class ) ) |
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{ |
292 | 0 | return ! step.getPredicates().isEmpty(); |
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} |
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else |
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{ |
296 | 4 | return true; |
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} |
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} |
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|
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} |
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|