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.Stack;
12 import java.util.Map.Entry;
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 || (initializationStatus == InitializationStatus.PARTIAL && navigator == null)) {
103 return;
104 }
105
106
107
108
109
110
111
112 nodeNameToXPaths = new HashMap<String, List<XPath>>();
113
114 BaseXPath originalXPath = createXPath(xpath, navigator);
115 indexXPath(originalXPath, AST_ROOT);
116
117 boolean useRuleChain = true;
118 Stack<Expr> pending = new Stack<Expr>();
119 pending.push(originalXPath.getRootExpr());
120 while (!pending.isEmpty()) {
121 Expr node = pending.pop();
122
123
124 boolean valid = false;
125
126
127 if (node instanceof LocationPath) {
128 LocationPath locationPath = (LocationPath) node;
129 if (locationPath.isAbsolute()) {
130
131 List<Step> steps = locationPath.getSteps();
132 if (steps.size() >= 2) {
133 Step step1 = steps.get(0);
134 Step step2 = steps.get(1);
135
136 if (step1 instanceof AllNodeStep && ((AllNodeStep) step1).getAxis() == Axis.DESCENDANT_OR_SELF) {
137
138 if (step2 instanceof NameStep && ((NameStep) step2).getAxis() == Axis.CHILD) {
139
140 XPathFactory xpathFactory = new DefaultXPathFactory();
141
142
143 LocationPath relativeLocationPath = xpathFactory.createRelativeLocationPath();
144
145 Step allNodeStep = xpathFactory.createAllNodeStep(Axis.SELF);
146
147 for (Iterator<Predicate> i = step2.getPredicates().iterator(); i.hasNext();) {
148 allNodeStep.addPredicate(i.next());
149 }
150 relativeLocationPath.addStep(allNodeStep);
151
152
153 for (int i = 2; i < steps.size(); i++) {
154 relativeLocationPath.addStep(steps.get(i));
155 }
156
157 BaseXPath xpath = createXPath(relativeLocationPath.getText(), navigator);
158 indexXPath(xpath, ((NameStep) step2).getLocalName());
159 valid = true;
160 }
161 }
162 }
163 }
164 } else if (node instanceof UnionExpr) {
165 UnionExpr unionExpr = (UnionExpr) node;
166 pending.push(unionExpr.getLHS());
167 pending.push(unionExpr.getRHS());
168 valid = true;
169 }
170 if (!valid) {
171 useRuleChain = false;
172 break;
173 }
174 }
175
176 if (useRuleChain) {
177
178 super.ruleChainVisits.addAll(nodeNameToXPaths.keySet());
179 } else {
180
181 nodeNameToXPaths.clear();
182 indexXPath(originalXPath, AST_ROOT);
183 if (LOG.isLoggable(Level.FINE)) {
184 LOG.log(Level.FINE, "Unable to use RuleChain for for XPath: " + xpath);
185 }
186 }
187
188 if (navigator == null) {
189 this.initializationStatus = InitializationStatus.PARTIAL;
190
191 nodeNameToXPaths = null;
192 } else {
193 this.initializationStatus = InitializationStatus.FULL;
194 }
195
196 }
197
198 private void indexXPath(XPath xpath, String nodeName) {
199 List<XPath> xpaths = nodeNameToXPaths.get(nodeName);
200 if (xpaths == null) {
201 xpaths = new ArrayList<XPath>();
202 nodeNameToXPaths.put(nodeName, xpaths);
203 }
204 xpaths.add(xpath);
205 }
206
207 private BaseXPath createXPath(String xpathQueryString, Navigator navigator) throws JaxenException {
208
209 BaseXPath xpath = new BaseXPath(xpathQueryString, navigator);
210 if (properties.size() > 1) {
211 SimpleVariableContext vc = new SimpleVariableContext();
212 for (Entry<PropertyDescriptor<?>, Object> e : properties.entrySet()) {
213 String propName = e.getKey().name();
214 if (!"xpath".equals(propName)) {
215 Object value = e.getValue();
216 vc.setVariableValue(propName, value != null ? value.toString() : null);
217 }
218 }
219 xpath.setVariableContext(vc);
220 }
221 return xpath;
222 }
223 }