Jackson : Pojo property multitype

Question

I use Jackson Library for serialization/deserialization.

I have a Pojo class with a property that i'm looking to be an Array and also support an object (through annotation if possible, for example : @Support(Actualite) ) in the same-time.

@JsonProperty @Support(Actualite)
    private ArrayList<Actualite> actualites;

Is there a way to do this ?

Please elaborate the question with an example so we can understand in a better way. — Sudhakar, May 12 '14 at 15:13
What do you mean by 'support an object'? Btw: There is no `@Support` annotation defined by Jackson. — Dirk Lachowski, May 12 '14 at 15:17
@DirkLachowski i mean that i can deseiralize an Actualite instance (`{`... }`) into my variable : `actualities` — TooCool, May 12 '14 at 15:20
@Editor i m looking to annotation not through code. Thank you — TooCool, May 12 '14 at 15:23

sksamuel · Answer 1 · 2014-05-12T15:41:00.093

1

I think what you are asking for is for Jackson to support a property as both an array, and an object for when there is only one value, eg

{ people : { name : "sam" } }

and

{ people : [ { name : "sam" }, { name : "bob" } ] }

In which case you'll want to add this to your mapper:

  mapper.configure(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED, true);
  mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);

Edit for Spring

You should be able to do something like this if you are using RestTemplate in Spring for Android:

// use false to turn off the default converts
RestTemplate restTemplate = new RestTemplate(false);

// create a new converter with the required features
MappingJacksonHttpMessageConverter converter = new MappingJacksonHttpMessageConverter();
ObjectMapper mapper = new ObjectMapper();
mapper.configure(SerializationFeature.WRITE_SINGLE_ELEM_ARRAYS_UNWRAPPED, true);
mapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
converter.setObjectMapper(mapper);

// register that as your converter
restTemplate.getMessageConverters().add(converter);

edited May 12 '14 at 15:41

answered May 12 '14 at 15:19

sksamuel

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i need an annotation please .. because i use Spring for android that integrate jackson mapper :) – TooCool May 12 '14 at 15:25
There must be a way of configuring the mapper that spring for android uses, or providing your own. – sksamuel May 12 '14 at 15:30
Are you using RestTemplate? – sksamuel May 12 '14 at 15:36
yes i use RestTemplate – TooCool May 12 '14 at 15:41
i get problem into converter.setObjectMapper(mapper); ?? – TooCool May 12 '14 at 15:46
What's the error message – sksamuel May 12 '14 at 16:13
any error they till me add build path – TooCool May 12 '14 at 16:19
That's not very useful. What's the actual error. – sksamuel May 12 '14 at 16:28
you can check http://postimg.org/image/flugpuadv/ – TooCool May 12 '14 at 17:08
let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/52540/discussion-between-abdellah-selassi-and-monkjack) – TooCool May 12 '14 at 17:49

Jackson : Pojo property multitype

1 Answers1