stax解析xml時， 使用棧來處理，不錯的代碼

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.Queue;
import java.util.Stack;


import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;

public class Parse {
	
	public static void main(String[] args) throws FileNotFoundException {

		
		String s=Parse.class.getResource("/").getFile()+"data.xml";
		
		 Stack stack=	new Parse().parse(new FileInputStream(s));
	
		 while(!stack.isEmpty()){
			 System.out.println(""+stack.pop());
			 
		 }
		
	
	}
	
	public Stack parse(InputStream in)
    {
        Stack stack = new Stack();
       
        try
        {
            //1.得到XMLStreamReader
            XMLInputFactory inputFactory = XMLInputFactory.newInstance();
            
            XMLStreamReader reader = inputFactory.createXMLStreamReader(in);
            int i=0;
            
            while (reader.hasNext())
            {
                //2.根據事件類型做相應的處理，對於多數應用來說，處理完成可以直接break，跳出循環，提高性能
                switch (reader.getEventType())
                {
                case XMLStreamReader.START_ELEMENT:
                    String name = reader.getLocalName();
                    if ("order".equals(name))
                    {
                    	System.out.println(++i);
                        Order order = new Order();
                        stack.push(order);
                    } else if ("item".equals(name))
                    {
                    	System.out.println("item");
                        Item item = new Item();
                        String sku = reader.getAttributeValue(0);
                        String quantity = reader.getAttributeValue(1);
                        item.setSku(sku);
                        item.setQuantity(Integer.parseInt(quantity));
                        stack.push(item);
                    } else if ("description".equals(name))
                    {
                    	System.out.println("description");
                        String desc = reader.getElementText();
                        Item item = (Item) stack.pop();
                        item.setDescription(desc);
                        Order order = (Order) stack.peek();
                        order.addItem(item);
                    }
                    break;
                }
                reader.next();//獲取下一個解析事件
            }
        } catch (XMLStreamException e)
        {            
            e.printStackTrace();
        }
        if (!stack.empty())
        {
            return stack;
        } else
        {
            return null;
        }
    }

}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE po SYSTEM "src/sample.dtd">
<po id="po121" submitted="2001-10-05" xmlns="http://www.csdn.net">
	<billTo id="addr-1">
		<company>The Redzero Cop.</company>
		<street>Jianguo Road 1ST</street>
		<street>Building 1</street>
		<city>Haidian</city>
		<state>Beijing</state>
		<postalCode>100071</postalCode>
	</billTo>
	<shipTo href="addr-1" />
	<order>
		<item sku="o318-BP" quantity="5">
			<description>J2EE programmic</description>
		</item>
		<item sku="o947-TI" quantity="12">
			<description>Java WEB Service</description>
		</item>
		<item sku="o008-PR" quantity="133">
			<description>C++ develop</description>
		</item>
	</order>
	
	<order>
		<item sku="o318-BP22" quantity="5">
			<description>J2EE programmic</description>
		</item>
		<item sku="o947-TI22" quantity="12">
			<description>Java WEB Service</description>
		</item>
		<item sku="o008-PR22" quantity="133">
			<description>C++ develop</description>
		</item>
	</order>
</po>