How to use Gson convert Java object to Json String (serialize POJO) with root value included

If you are using Gson library (google-gsonA Java library to convert JSON to Java objects and vice-versa) and you want to serialize POJO with root value included like the following illustrated code for serializing XML.

@XmlRootElement
class Person implements Serializable {
    private String firstname;
    private String lastname;
    public Person() {
    firstname="firstname";
    lastname="lastname";
   }
}
......

It’s very simple, here is an example to do it with Gson:

    Gson gson = new Gson();
    JsonElement je = gson.toJsonTree(new Person());
    JsonObject jo = new JsonObject();
    jo.add("PersonRoot",je);