XML文件 
      
          
               
      
       John
                
      
       B
                
      
       12
            
           
               
      
       Mary
                
      
       A
                
      
       11
            
           
               
      
       Simon
                
      
       A
                
      
       18
            
       
    

package net.viralpatel.java.xmlparser; import java.io.File;   import javax.xml.parsers.DocumentBuilder;  import javax.xml.parsers.DocumentBuilderFactory;      import org.w3c.dom.Document;   import org.w3c.dom.Element;   import org.w3c.dom.Node;   import org.w3c.dom.NodeList;     public class XMLParser {        	public void getAllUserNames(String fileName) {    		try {            			DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();             			DocumentBuilder db = dbf.newDocumentBuilder();          			File file = new File(fileName);               			if (file.exists()) {              				Document doc = db.parse(file);            				Element docEle = doc.getDocumentElement();                     				// Print root element of the document            				System.out.println("Root element of the document: "                         + docEle.getNodeName()); 				NodeList studentList = docEle.getElementsByTagName("student");       				// Print total student elements in document              				System.out.println("Total students: " + studentList.getLength()); 				if (studentList != null && studentList.getLength() > 0) {   					for (int i = 0; i < studentList.getLength(); i++) {    						Node node = studentList.item(i);                         						if (node.getNodeType() == Node.ELEMENT_NODE) {    							System.out.println("=====================");     							Element e = (Element) node;                              							NodeList nodeList = e.getElementsByTagName("name");							System.out.println("Name: "     + nodeList.item(0).getChildNodes().item(0).getNodeValue());                    							nodeList = e.getElementsByTagName("grade");   							System.out.println("Grade: " + nodeList.item(0).getChildNodes().item(0).getNodeValue());							nodeList = e.getElementsByTagName("age");    							System.out.println("Age: " + nodeList.item(0).getChildNodes().item(0).getNodeValue());             							}                       }                   					} else {            						System.exit(1);        						}               }        			} catch (Exception e) {          				System.out.println(e);        				}      			}      	public static void main(String[] args) {           		XMLParser parser = new XMLParser();           				}					parser.getAllUserNames("c:\\test.xml");     		}  	} }