xpath无法读取xml

package testdemo1;

import java.util.List;

import org.dom4j.Document;

import org.dom4j.DocumentException;

import org.dom4j.Element;

import org.dom4j.Node;

import org.dom4j.io.SAXReader;

public class xPathXml {

public void testXPathXml(String xPathStr) {

String file="d:/eclipse-workspace/xmlTest/src/plan.xml";

SAXReader sax = new SAXReader();

try {

Document dm = sax.read(file);

List<Node> nodes = dm.selectNodes(xPathStr);

System.out.println(nodes.size());

for(Node node : nodes) {

Element course = (Element)node;

System.out.print(course.attributeValue("id"));

System.out.print(course.elementText("course-name"));

System.out.print(course.elementText("class-hour"));

System.out.print(course.elementText("exam-form"));

}

} catch (Exception e) {

e.printStackTrace();

}

}

public static void main(String[] args) {

// TODO Auto-generated method stub

xPathXml xpathxml = new xPathXml();

xpathxml.testXPathXml("//scoure");

// xpathxml.testXPathXml("//scoure[class-hour<50]");

// xpathxml.testXPathXml("//scoure[course-name='高等数学']");

// xpathxml.testXPathXml("//scoure[@id='001']");

// xpathxml.testXPathXml("//scoure[position<3]");

}

}

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<?xml version="1.0" encoding="UTF-8"?>

<teaching-plan>

<course id="001">

<course-name>大学英语</course-name>

<class-hour>36</class-hour>

<exam-form>考试</exam-form>

</course>

<course id="002">

<course-name>高等数学</course-name>

<class-hour>70</class-hour>

<exam-form>考试</exam-form>

</course>

<course id="003">

<course-name>计算机应用基础</course-name>

<class-hour>108</class-hour>

<exam-form>上机考试</exam-form>

</course>

</teaching-plan>