@JsonWrapped for Jackson

A conterpart for @JsonUnwrapped for serialization.

Annotation used to indicate that a property should be serialized wrapped in a virtual object; that is, if it would be serialized it is instead included as a property of the virtual object.

In other words, it does create a virtual property of a JSON object and moves the original property into it.

No need for artificial wrapping objects or custom serializer quirks.

Usage (Example from @JsonUnwrapped)

For example, consider case of POJO like:

public class Parent {
    public int age;
    public String first, last;
}

which would normally be serialized as follows:

{
    "age": 18,
    "first": "Joey",
    "last": "Sixpack"
}

can be changed to this:

{
    "age": 18,
    "name": {
      "first": "Joey",
      "last": "Sixpack"
    }
}

by changing Parent class to:

public class Parent {
    public int age;
    @JsonWrapped("name")
    public String first, last;
}

or

@JsonWrapped(value="name", properties={"first","last"})
public class Parent {
    public int age;
    public String first, last;
}

Configuration

Simply register the annotation with a module:

new ObjectMapper().registerModule(new JsonWrappedModule());

Features

• @JsonWrapped annotations can be placed at property (field or method) level and type (class) level

• @JsonWrapped annotations at property and type level with the same virtual property name can be combined, configuration on property level has precedence

• multiple @JsonWrapped annotations with different names for the virtual property can be used, resulting in multiple virtual objects:

   @JsonWrapped(value="name", properties={"first","last})
   public class Parent {
       public int age;
       @JsonWrapped("name")
       public String first, last;
       @JsonWrapped("address")
       public String street, city;
   }
  

  would be serialized as

   {
       "age" : 18,
       "name": {
           "first": "Joey",
           "last": "Sixpack"
       },
       "address": {
           "street": "Sunset boulevard",
           "city": "Heaven"
       }
   }
  

• respects the standard annotations like @JsonProperty, @JsonIgnore, ...

• respects views via @JsonView on properties

• supports views on the created virtual property via @JsonWrapped(value="myVirtualProp",views={View.class}), views of multiple annotations with the same name for the virtual property are combined, configuration on property level has precedence

• supports filtering of properties by @JsonFilter and the created virtual properties

• supports wrapping of properties produced by @AnyGetter