docs: public static String toXml(Object object) {
          if (object == null) {
              throw new NullPointerException("object对象不存在!");
          }
          JAXBContext jc = null;
          Marshaller m = null;
          String xml = null;
          try {
              jc = JAXBContext.newInstance(object.getClass());
              m = jc.createMarshaller();
              ByteArrayOutputStream bos = new ByteArrayOutputStream();
              m.marshal(object, bos);
              xml = new String(bos.toByteArray());
          } catch (Exception e) {
              throw new RuntimeException(e);
          }
          return xml;
      }