Extensible Markup Language (XML) 是一组将文档编码成机器可读形式的规则，也是一种在网络上共享数据的普遍格式。经常更新内容的网站比如新闻网站和博客上都提供XML Feed来记录更新的信息，以便用户进行订阅读取。

解析器我们用XMLPullParser ，Android 官网推荐。如果对xml不熟悉可以先看下http://www.w3cschool.cc/xml/xml-tutorial.html;

今天写的demo是基于上次的AsyncTask之下载HTML的扩充 ，首先我写了一个persons.xml

<?xml version="1.0" encoding="UTF-8"?>  
<persons>  
    <person id="1">  
        <name>Tom</name>  
        <age>21</age>  
    </person>  
    <person id="2">  
        <name>Rose</name>  
        <age>22</age>  
    </person>  
     <person id="3">  
        <name>Jack</name>  
        <age>20</age>  
    </person> 
</persons> 

接下来在工程下写一个Person JavaBean:

public class Person {
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}	
	public Short getAge() {
		return age;
	}
	public void setAge(Short age) {
		this.age = age;
	}
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	private Integer id;
	private String name;
	private Short age;
}

在MainActivity加入 readXML():

	public List<Person> readXML(InputStream inStream) {
//		Log.i("LIST","startReadXML");
		//创建解析器对象，生成实例
		XmlPullParser parser = Xml.newPullParser();
		try {
			parser.setInput(inStream,"UTF-8");// 设置数据源编码
			int eventType = parser.getEventType();// 获取事件类型
			Person currentPerson = null;
			List<Person> persons = null;
			while (eventType != XmlPullParser.END_DOCUMENT) {
				switch (eventType) {
				case XmlPullParser.START_DOCUMENT:// 文档开始事件,可以进行数据初始化处理
					persons = new ArrayList<Person>();// 实例化集合类
					break;
				case XmlPullParser.START_TAG:// 开始读取某个标签
					// 通过getName判断读到哪个标签，然后通过nextText()获取文本节点值，或通过getAttributeValue(i)获取属性节点值
					String name = parser.getName();
					if (name.equalsIgnoreCase("person")) {
						currentPerson = new Person();
						currentPerson.setId(new Integer(parser
								.getAttributeValue(null,"id")));
					} else if (currentPerson != null) {
						if (name.equalsIgnoreCase("name")) {
							currentPerson.setName(parser.nextText());// 如果后面是Text元素,即返回它的值
							Log.i("LIST",currentPerson.getName());
						} else if (name.equalsIgnoreCase("age")) {
							currentPerson.setAge(new Short(parser.nextText()));
						}
					}
					break;
				case XmlPullParser.END_TAG:// 结束元素事件
					// 读完一个Person，可以将其添加到集合类中
					if (parser.getName().equalsIgnoreCase("person")
							&& currentPerson != null) {
						persons.add(currentPerson);
						currentPerson = null;
					}
					break;
				}
				eventType = parser.next();
			}
			inStream.close();
			return persons;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

			//获取InputSream
			is = conn.getInputStream();
			//把InputStream 转为 String
//			String contentAsString = readIt(is,len);
			StringBuilder strBuilder = new StringBuilder();
			List<Person> list = readXML(is);
			for (int i = 0; i < list.size(); i++) {
				strBuilder.append("id:" + list.get(i).getId() + "\n");
				strBuilder.append("name:" + list.get(i).getName() + "\n");
				strBuilder.append("age:" + list.get(i).getAge() + "\n");
				strBuilder.append("==========\n");
			}
			return strBuilder.toString();