参考：
http://www.cnblogs.com/zixin/category/60411.html
import java.util.*; import org.jdom.*;
import org.jdom.xpath.*;
import org.jdom.input.*;
import org.jdom.output.*;
import java.io.*;
import org.jdom.xpath.*;
import org.saxpath.*;
public class TestXML {
public static void main(String[] args) {
try {
SAXBuilder sb = new SAXBuilder();
Document doc = sb.build(new FileInputStream("/book.xml"));
String strPath = "//book/author";
XPath path = XPath.newInstance(strPath);
List lst = path.selectNodes(doc);
for (Iterator it = lst.iterator(); it.hasNext();) {
Element at = (Element) it.next();
System.out.println(at.getText());
}
} catch (Exception e) {
e.printStackTrace();
}
}
}