XmlPullParser
	事件解析-->
		可以获取每个节点事件,获取到属性或节点文本
		
		XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
		XmlPullParser parser = factory.newPullParser();
		parser.setInput(is, "utf-8");
		//获取类型
		int eventType = parser.getEventType();
		ArrayList<Student>list=new ArrayList<>();
		ArrayList<Friend>friends=new ArrayList<>();
		Student stu = null;
		Friend f = null;
		//不到达文档最后则继续循环操作
		while(eventType!=XmlPullParser.END_DOCUMENT){
			switch (eventType) {
			case XmlPullParser.START_TAG:
				switch (parser.getName()) {
				case "student":


XStream
	xml-->javabean	将每节点转换,属性转换不了
	
	public static ArrayList<Student> streamToObject2(InputStream is){
		XStream xStream = new XStream();
		xStream.alias("students", ArrayList.class);
		xStream.alias("student", Student.class);
		xStream.alias("friends", ArrayList.class);
		xStream.alias("friend", Friend.class);
		ArrayList<Student> list = (ArrayList<Student>) xStream.fromXML(is);
		
		return list;
	}