How to use Jackson to deserialise an array of objects

jackson, java, json

Solution

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));

Problem

The Jackson data binding documentation indicates that Jackson supports deserialising "Arrays of all supported types" but I can't figure out the exact syntax for this. For a single object I would do this: ``` //json input { "id" : "junk", "stuff" : "things" } //Java MyClass instance = objectMapper.readValue(json, MyClass.class); ``` Now for an array I want to do this: ``` //json input [{ "id" : "junk", "stuff" : "things" }, { "id" : "spam", "stuff" : "eggs" }] //Java List<MyClass> entries = ? ``` Anyone know if there is a magic missing command? If not then what is the solution?

Original source