步骤：

1.获取xml文件的pull解析器

2.指定要解析的xml文件（传入的输入流），编码方式

3.当没到文档结尾，就一直循环，获取对应标签的信息，存入javabean中

	public static List<WeatherInfo> getWeatherInfos(InputStream is) throws Exception{
		XmlPullParser parser = Xml.newPullParser();
		//初始化解析器
		parser.setInput(is,"utf-8");
		List<WeatherInfo> weatherInfos = null;
		WeatherInfo weatherInfo = null;
		int type = parser.getEventType();
		while (type!=XmlPullParser.END_DOCUMENT) {
			switch (type) {
			case XmlPullParser.START_TAG:
				if("infos".equals(parser.getName())){
					//解析到全局开始的标签
					weatherInfos = new ArrayList<WeatherInfo>();
				}else if("city".equals(parser.getName())){
					weatherInfo = new WeatherInfo();
					String idStr = parser.getAttributeValue(0);
					weatherInfo.setId(Integer.parseInt(idStr));
				}else if("temp".equals(parser.getName())){
					String temp = parser.nextText();
					weatherInfo.setTemp(temp);
				}else if("weather".equals(parser.getName())){
					String weather = parser.nextText();
					weatherInfo.setWeather(weather);
				}else if("wind".equals(parser.getName())){
					String wind = parser.nextText();
					weatherInfo.setWind(wind);
				}else if("name".equals(parser.getName())){
					String name = parser.nextText();
					weatherInfo.setName(name);
				}else if("pm".equals(parser.getName())){
					String pm = parser.nextText();
					weatherInfo.setPm(pm);
				}
				break;

			case XmlPullParser.END_TAG:
				if("city".equals(parser.getName())){
					weatherInfos.add(weatherInfo);
					weatherInfo = null;
				}
				break;
			}
			
			type = parser.next();
		}
		return weatherInfos;
	}