Can you build the array as an object before writing it, rather than bothering with all the individual pieces?

ObjectMapper mapper = new ObjectMapper();
ArrayNode array = mapper.createArrayNode();

int i = 0;
while (i < 6) {
    array.add(mapper.createArrayNode().add("" + i++).add("" + i++));
}
System.out.println(array);

Results in:

[["0","1"],["2","3"],["4","5"]]

If you're not dealing with several megabytes of data or very tight memory constraints, this might turn out to be more maintainable as well.

First create a mapper :

import com.fasterxml.jackson.databind.ObjectMapper;// in play 2.3
ObjectMapper mapper = new ObjectMapper();

As Array:

MyClass[] myObjects = mapper.readValue(json, MyClass[].class);

As List:

List<MyClass> myObjects = mapper.readValue(jsonInput, new TypeReference<List<MyClass>>(){});

Another way to specify the List type:

List<MyClass> myObjects = mapper.readValue(jsonInput, mapper.getTypeFactory().constructCollectionType(List.class, MyClass.class));

I finally got it:

ObjectMapper objectMapper = new ObjectMapper();
TypeFactory typeFactory = objectMapper.getTypeFactory();
List<SomeClass> someClassList = objectMapper.readValue(jsonString, typeFactory.constructCollectionType(List.class, SomeClass.class));

http://www.baeldung.com/jackson-inheritance

You'll need to have those types inherit from one base class though.

Also; that is really bad JSON.

I got it working by adding a custom serializer:

class Foo {
    @JsonSerialize(using = MySerializer.class)
    private List<String> fooElements;
}

public class MySerializer extends JsonSerializer<Object> {

    @Override
    public void serialize(Object value, JsonGenerator jgen, SerializerProvider provider)
            throws IOException, JsonProcessingException {
        List<String> fooList = (List<String>) value;

        if (fooList.isEmpty()) {
            return;
        }

        String fooValue = fooList.get(0);
        String[] fooElements = fooValue.split(",");

        jgen.writeStartArray();
        for (String fooValue : fooElements) {
            jgen.writeString(fooValue);
        }
        jgen.writeEndArray();
    }
}