1
2
3
4 package net.sourceforge.pmd.lang.rule.xpath;
5
6 import java.util.ArrayList;
7 import java.util.HashMap;
8 import java.util.Iterator;
9 import java.util.List;
10 import java.util.Map;
11 import java.util.Map.Entry;
12 import java.util.Stack;
13 import java.util.logging.Level;
14 import java.util.logging.Logger;
15
16 import net.sourceforge.pmd.PropertyDescriptor;
17 import net.sourceforge.pmd.RuleContext;
18 import net.sourceforge.pmd.lang.ast.Node;
19
20 import org.jaxen.BaseXPath;
21 import org.jaxen.JaxenException;
22 import org.jaxen.Navigator;
23 import org.jaxen.SimpleVariableContext;
24 import org.jaxen.XPath;
25 import org.jaxen.expr.AllNodeStep;
26 import org.jaxen.expr.DefaultXPathFactory;
27 import org.jaxen.expr.Expr;
28 import org.jaxen.expr.LocationPath;
29 import org.jaxen.expr.NameStep;
30 import org.jaxen.expr.Predicate;
31 import org.jaxen.expr.Step;
32 import org.jaxen.expr.UnionExpr;
33 import org.jaxen.expr.XPathFactory;
34 import org.jaxen.saxpath.Axis;
35
36
37
38
39 public class JaxenXPathRuleQuery extends AbstractXPathRuleQuery {
40
41 private static final Logger LOG = Logger.getLogger(JaxenXPathRuleQuery.class.getName());
42
43 private static enum InitializationStatus {
44 NONE, PARTIAL, FULL
45 };
46
47
48 private InitializationStatus initializationStatus = InitializationStatus.NONE;
49 private Map<String, List<XPath>> nodeNameToXPaths;
50
51 private static final String AST_ROOT = "_AST_ROOT_";
52
53
54
55
56 @Override
57 public boolean isSupportedVersion(String version) {
58 return XPATH_1_0.equals(version);
59 }
60
61
62
63
64 @Override
65 @SuppressWarnings("unchecked")
66 public List<Node> evaluate(Node node, RuleContext data) {
67 List<Node> results = new ArrayList<Node>();
68 try {
69 initializeXPathExpression(data.getLanguageVersion().getLanguageVersionHandler().getXPathHandler()
70 .getNavigator());
71 List<XPath> xpaths = nodeNameToXPaths.get(node.toString());
72 if (xpaths == null) {
73 xpaths = nodeNameToXPaths.get(AST_ROOT);
74 }
75 for (XPath xpath : xpaths) {
76 List<Node> nodes = xpath.selectNodes(node);
77 results.addAll(nodes);
78 }
79 } catch (JaxenException ex) {
80 throw new RuntimeException(ex);
81 }
82 return results;
83 }
84
85
86
87
88 @Override
89 public List<String> getRuleChainVisits() {
90 try {
91
92 initializeXPathExpression(null);
93 return super.getRuleChainVisits();
94 } catch (JaxenException ex) {
95 throw new RuntimeException(ex);
96 }
97 }
98
99 @SuppressWarnings("unchecked")
100 private void initializeXPathExpression(Navigator navigator) throws JaxenException {
101 if (initializationStatus == InitializationStatus.FULL) {
102 return;
103 } else if (initializationStatus == InitializationStatus.PARTIAL && navigator == null) {
104 LOG.severe("XPathRule is not initialized because no navigator was provided. "
105 + "Please make sure to implement getXPathHandler in the handler of the language. "
106 + "See also AbstractLanguageVersionHandler.");
107 return;
108 }
109
110
111
112
113
114
115
116 nodeNameToXPaths = new HashMap<String, List<XPath>>();
117
118 BaseXPath originalXPath = createXPath(xpath, navigator);
119 indexXPath(originalXPath, AST_ROOT);
120
121 boolean useRuleChain = true;
122 Stack<Expr> pending = new Stack<Expr>();
123 pending.push(originalXPath.getRootExpr());
124 while (!pending.isEmpty()) {
125 Expr node = pending.pop();
126
127
128 boolean valid = false;
129
130
131 if (node instanceof LocationPath) {
132 LocationPath locationPath = (LocationPath) node;
133 if (locationPath.isAbsolute()) {
134
135 List<Step> steps = locationPath.getSteps();
136 if (steps.size() >= 2) {
137 Step step1 = steps.get(0);
138 Step step2 = steps.get(1);
139
140 if (step1 instanceof AllNodeStep && ((AllNodeStep) step1).getAxis() == Axis.DESCENDANT_OR_SELF) {
141
142 if (step2 instanceof NameStep && ((NameStep) step2).getAxis() == Axis.CHILD) {
143
144 XPathFactory xpathFactory = new DefaultXPathFactory();
145
146
147 LocationPath relativeLocationPath = xpathFactory.createRelativeLocationPath();
148
149 Step allNodeStep = xpathFactory.createAllNodeStep(Axis.SELF);
150
151 for (Iterator<Predicate> i = step2.getPredicates().iterator(); i.hasNext();) {
152 allNodeStep.addPredicate(i.next());
153 }
154 relativeLocationPath.addStep(allNodeStep);
155
156
157 for (int i = 2; i < steps.size(); i++) {
158 relativeLocationPath.addStep(steps.get(i));
159 }
160
161 BaseXPath xpath = createXPath(relativeLocationPath.getText(), navigator);
162 indexXPath(xpath, ((NameStep) step2).getLocalName());
163 valid = true;
164 }
165 }
166 }
167 }
168 } else if (node instanceof UnionExpr) {
169 UnionExpr unionExpr = (UnionExpr) node;
170 pending.push(unionExpr.getLHS());
171 pending.push(unionExpr.getRHS());
172 valid = true;
173 }
174 if (!valid) {
175 useRuleChain = false;
176 break;
177 }
178 }
179
180 if (useRuleChain) {
181
182 super.ruleChainVisits.addAll(nodeNameToXPaths.keySet());
183 } else {
184
185 nodeNameToXPaths.clear();
186 indexXPath(originalXPath, AST_ROOT);
187 if (LOG.isLoggable(Level.FINE)) {
188 LOG.log(Level.FINE, "Unable to use RuleChain for for XPath: " + xpath);
189 }
190 }
191
192 if (navigator == null) {
193 this.initializationStatus = InitializationStatus.PARTIAL;
194
195 nodeNameToXPaths = null;
196 } else {
197 this.initializationStatus = InitializationStatus.FULL;
198 }
199
200 }
201
202 private void indexXPath(XPath xpath, String nodeName) {
203 List<XPath> xpaths = nodeNameToXPaths.get(nodeName);
204 if (xpaths == null) {
205 xpaths = new ArrayList<XPath>();
206 nodeNameToXPaths.put(nodeName, xpaths);
207 }
208 xpaths.add(xpath);
209 }
210
211 private BaseXPath createXPath(String xpathQueryString, Navigator navigator) throws JaxenException {
212
213 BaseXPath xpath = new BaseXPath(xpathQueryString, navigator);
214 if (properties.size() > 1) {
215 SimpleVariableContext vc = new SimpleVariableContext();
216 for (Entry<PropertyDescriptor<?>, Object> e : properties.entrySet()) {
217 String propName = e.getKey().name();
218 if (!"xpath".equals(propName)) {
219 Object value = e.getValue();
220 vc.setVariableValue(propName, value != null ? value.toString() : null);
221 }
222 }
223 xpath.setVariableContext(vc);
224 }
225 return xpath;
226 }
227 }