arg1.setContentType("application/json; charset=UTF-8");
arg1.setHeader("Cache-Control", "no-cache");
PrintWriter out = arg1.getWriter();
XStream xstream = new XStream(new JsonHierarchicalStreamDriver() {
public HierarchicalStreamWriter createWriter(Writer writer) {
return new JsonWriter(writer, JsonWriter.DROP_ROOT_MODE);
}
});