Force Jackson to add addional wrapping using annotations

With Jackson 2.x use can use the following to enable wrapper without adding addition properties in the ObjectMapper

import com.fasterxml.jackson.annotation.JsonTypeInfo;
import com.fasterxml.jackson.annotation.JsonTypeName;

@JsonTypeInfo(include = JsonTypeInfo.As.WRAPPER_OBJECT, use = JsonTypeInfo.Id.NAME)
@JsonTypeName(value = "student")
public class Student {
  private String name;
  private String id;
}

On workaround: you don't absolutely need those getters/setters, so could just have:

public class MessageWrapper {
  public Message message;
}

or perhaps add convenience constructor:

public class MessageWrapper {
  public Message message;
  @JsonCreator
  public MessageWrapper(@JsonProperty("message") Message m) { 
       message = m; 
  }
}

There is a way to add wrapping too; with 1.9 you can use SerializationConfig.Feature.WRAP_ROOT_ELEMENT and DeserializationConfig.Feature.UNWRAP_ROOT_ELEMENT. And if you want to change the wrapper name (by default it is simply unqualified class name), you can use @JsonRootName annotation

Jackson 2.0 adds further dynamic options via ObjectReader and ObjectWriter, as well as JAX-RS annotations.

It was sad to learn that you must write custom serialization for the simple goal of wrapping a class with a labeled object. After playing around with writing a custom serializer, I concluded that the simplest solution is a generic wrapper. Here's perhaps a more simple implementation of your example above:

public final class JsonObjectWrapper {
    private JsonObjectWrapper() {}

    public static <E> Map<String, E> withLabel(String label, E wrappedObject) {
        HashMap<String, E> map = new HashMap<String, E>();
        map.put(label, wrappedObject);
        return map;
    }
}

Provided you don't mind the json having a capital m in message, then the simplest way to do this is to annotate your class with @JsonTypeInfo.

You would add:

@JsonTypeInfo(include=As.WRAPPER_OBJECT, use=Id.NAME)
public class Message {
  // ...
}

to get {"Message":{"text":"Text"}}