How to unwrap single item array and extract value field into one simple field?

Question

I have a JSON document similar to the following:

{
  \"aaa\": [
    {
      \"value\": \"wewfewfew\"
    }
  ],
  \"bbb\": [
    {
      \"value\": \"wefwefw\"
          


        

Answer 1

For completeness, if you use jackson, you can enable the deserialization feature UNWRAP_SINGLE_VALUE_ARRAYS. To do that, you have to enable it for the ObjectMapper like so:

ObjectMapper objMapper = new ObjectMapper()
    .enable(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS);

With that, you can just read the class as you are being used to in Jackson. For example, assuming the class Person:

public class Person {
    private String name;
    // assume getter, setter et al.
}

and a json personJson:

{
    "name" : [
        "John Doe"
    ]
}

We can deserialize it via:

ObjectMapper objMapper = new ObjectMapper()
    .enable(DeserializationFeature.UNWRAP_SINGLE_VALUE_ARRAYS);

Person p = objMapper.readValue(personJson, Person.class);