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1
57
59 import net.sf.saxon.om.NamespaceConstant;
60 import net.sf.saxon.xpath.XPathEvaluator;
61 import org.jdom.input.SAXBuilder;
62 import org.w3c.dom.Document  ;
63 import org.xml.sax.InputSource ;
64
65 import javax.xml.namespace.NamespaceContext ;
66 import javax.xml.namespace.QName ;
67 import javax.xml.parsers.DocumentBuilderFactory ;
68 import javax.xml.transform.OutputKeys ;
69 import javax.xml.transform.Transformer ;
70 import javax.xml.transform.TransformerFactory ;
71 import javax.xml.transform.stream.StreamSource ;
72 import javax.xml.xpath.*;
73 import java.io.File ;
74 import java.io.FileInputStream ;
75 import java.util.Iterator ;
76 import java.util.List ;
77
78
79
101 public class ApplyXPathJAXP {
102 protected String filename = null;
103 protected String xpathExpressionStr = null;
104 protected String objectModel = null;
105
106
109 public void doMain(String [] args)
110 throws Exception {
111 filename = args[0];
112 xpathExpressionStr = args[1];
113 String om = "saxon";
114 if (args.length > 2) {
115 om = args[2];
116 }
117 if (om.equals("saxon")) {
118 objectModel = NamespaceConstant.OBJECT_MODEL_SAXON;
119 } else if (om.equals("dom")) {
120 objectModel = XPathConstants.DOM_OBJECT_MODEL;
121 } else if (om.equals("jdom")) {
122 objectModel = NamespaceConstant.OBJECT_MODEL_JDOM;
123 } else if (om.equals("xom")) {
124 objectModel = NamespaceConstant.OBJECT_MODEL_XOM;
125 } else {
126 System.err.println("Unknown object model " + args[2]);
127 return;
128 }
129
130 if ((filename != null) && (filename.length() > 0)
131 && (xpathExpressionStr != null) && (xpathExpressionStr.length() > 0)) {
132 System.out.println("Loading classes, parsing " + filename + ", and setting up serializer");
136
137 Object document = null;
138 if (objectModel.equals(NamespaceConstant.OBJECT_MODEL_SAXON)) {
139 document = new XPathEvaluator().setSource(new StreamSource (new File (filename)));
140
141 } else if (objectModel.equals(XPathConstants.DOM_OBJECT_MODEL)) {
142 InputSource in = new InputSource (new FileInputStream (filename));
143 DocumentBuilderFactory dfactory = DocumentBuilderFactory.newInstance();
144 dfactory.setNamespaceAware(true);
145 Document doc = dfactory.newDocumentBuilder().parse(in);
146 document = doc;
147
148 } else if (objectModel.equals(NamespaceConstant.OBJECT_MODEL_JDOM)) {
149 InputSource in = new InputSource (new FileInputStream (filename));
150 SAXBuilder builder = new SAXBuilder();
151 document = builder.build(in);
152
153 } else if (objectModel.equals(NamespaceConstant.OBJECT_MODEL_XOM)) {
154 nu.xom.Builder builder = new nu.xom.Builder();
155 document = builder.build(new FileInputStream (filename));
156 }
157
158 Transformer serializer = TransformerFactory.newInstance().newTransformer();
160 serializer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
161
162 System.out.println("Querying " + om + " using " + xpathExpressionStr);
164
165 System.setProperty("javax.xml.xpath.XPathFactory:"+NamespaceConstant.OBJECT_MODEL_SAXON,
167 "net.sf.saxon.xpath.XPathFactoryImpl");
168 System.setProperty("javax.xml.xpath.XPathFactory:"+XPathConstants.DOM_OBJECT_MODEL,
169 "net.sf.saxon.xpath.XPathFactoryImpl");
170 System.setProperty("javax.xml.xpath.XPathFactory:"+NamespaceConstant.OBJECT_MODEL_JDOM,
171 "net.sf.saxon.xpath.XPathFactoryImpl");
172 System.setProperty("javax.xml.xpath.XPathFactory:"+NamespaceConstant.OBJECT_MODEL_XOM,
173 "net.sf.saxon.xpath.XPathFactoryImpl");
174
175 XPathFactory xpathFactory = XPathFactory.newInstance(objectModel);
178 XPath xpath = xpathFactory.newXPath();
179
180 xpath.setNamespaceContext(
182 new NamespaceContext () {
183 public String getNamespaceURI(String s) {
184 if (s.equals("f")) {
185 return "http://localhost/f";
186 } else {
187 return null;
188 }
189 }
190
191 public String getPrefix(String s) { return null; }
192
193 public Iterator getPrefixes(String s) { return null; }
194 }
195 );
196
197
199 final QName f_var = new QName ("http://localhost/f", "pi");
200 xpath.setXPathVariableResolver(
201 new XPathVariableResolver() {
202 public Object resolveVariable(QName qName) {
203 if (qName.equals(f_var)) {
204 return new Double (Math.PI);
205 } else {
206 return null;
207 }
208 }
209 }
210 );
211
212
214 final XPathFunction sqrt = new XPathFunction() {
215 public Object evaluate(List list) throws XPathFunctionException {
216 Object arg = list.get(0);
217 if (!(arg instanceof Double )) {
218 throw new XPathFunctionException("f:sqrt() expects an xs:double argument");
219 }
220 return new Double (Math.sqrt(((Double )arg).doubleValue()));
221 }
222 };
223
224 final QName f_sqrt = new QName ("http://localhost/f", "sqrt");
225 xpath.setXPathFunctionResolver(
226 new XPathFunctionResolver() {
227 public XPathFunction resolveFunction(QName qName, int arity) {
228 if (qName.equals(f_sqrt) && arity==1) {
229 return sqrt;
230 } else {
231 return null;
232 }
233 }
234 }
235 );
236
237
238 XPathExpression xpathExpression = xpath.compile(xpathExpressionStr);
240
241
242 String resultString = xpathExpression.evaluate(document);
244
245 System.out.println("<output>");
247 System.out.println("String Value => " + resultString);
248 System.out.println("</output>");
249 } else {
250 System.out.println("Bad input args: " + filename + ", " + xpathExpressionStr);
251 }
252 }
253
254
255
258 public static void main(String [] args)
259 throws Exception {
260 if (args.length != 2 && args.length != 3) {
261 System.out.println("java ApplyXPathJAXP filename.xml xpath [saxon|dom|jdom|xom]\n"
262 + "Reads filename.xml and applies the xpath; prints the String value of result.");
263 return;
264 }
265
266 ApplyXPathJAXP app = new ApplyXPathJAXP();
267 app.doMain(args);
268 }
269
270 }
272 |
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