利用java Api解析XML

import java.io.IOException;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
/**
 * Usage: You can get a instance of Document from a string of xml.
 * This class supply some method to read a document.
 *
 */
public class XMLParser {
 /**
  * Get a instance of Document from a string of xml.
  *
  * @param xmlStr
  * @return Document
  */
 public static Document parse(String xmlStr) {
  if (xmlStr == null) {
   return null;
  }
  StringReader reader = new StringReader(xmlStr);
  InputSource source = new InputSource(reader);
  DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
  DocumentBuilder builder = null;
  try {
   builder = factory.newDocumentBuilder();
   
  } catch (ParserConfigurationException e) {
   e.printStackTrace();
  }
  if(builder == null){
   return null;
  }
  Document doc = null;
  try {
   doc = builder.parse(source);
  } catch (SAXException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
  return doc;
 }
 
 /**
  * Get Item Value.
  * @param node
  * @return String
  */
 public static String getItemValue(Node node){
  String value = "";
  if(node == null){
   retur