Parsing Json file with Jackson

Question

I call a WS that returns a Json object like follows:

 { "id": "salton", "name": "salton", }

which I parse without any problem using

ObjectMapper mapper = new ObjectMapper(); return mapper.readValue(jsonStr, Show.class);

Then I have another WS that return a list of objects, as follows

{ "id": "saltonId", "name": "salton", }, { "id": "elCordeLaCiutat", "name": "elCordeLaCiutat", }

which I want to parse using

ObjectMapper mapper = new ObjectMapper(); return mapper.readValue(jsonStr, List<Show.class>.class);

but I got compilation problems

Multiple markers at this line - List cannot be resolved to a variable - Syntax error on token ">", byte expected after this token

Use mapper.readValue(jsonStr, mapper.getTypeFactory().constructCollectionType(List.class, Show.class)); — Rouliboy
– Rouliboy, Commented Jan 22, 2018 at 9:01

senerh · Accepted Answer · 2018-01-22 09:32:31Z

A list of objects should be wrapped in [] as follows

[ { "id": "saltonId", "name": "salton", }, { "id": "elCordeLaCiutat", "name": "elCordeLaCiutat", } ]

which you can unmarchal like that:

ObjectMapper mapper = new ObjectMapper(); List<Show> shows = Arrays.asList(mapper.readValue(json, Show[].class));

Nunyet Calçada · Accepted Answer · 2018-01-22 09:24:32Z

Type listType = new TypeToken<List<Show>>() {}.getType(); return mapper.readValue(jsonStr, listType.class);

2 Answers 2