/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Node node = new Node();
node.setId(0);
node.setOs("ipad");
node.setPv(100);
node.setVv(1000);
node.setDate("2013-07-09");
JSONObject ja = JSONObject.fromObject(node);
System.out.println(ja.toString());
}