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, Jan 22 '18 at 09:01
See https://stackoverflow.com/questions/6349421/how-to-use-jackson-to-deserialise-an-array-of-objects — jeet427, Jan 22 '18 at 09:14

senerh · Accepted Answer · 2018-01-22T09:32:31.567

1

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));

edited Jan 22 '18 at 09:32

answered Jan 22 '18 at 09:27

senerh

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score 0 · Answer 2 · answered Jan 22 '18 at 09:24

0

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

answered Jan 22 '18 at 09:24

Nuñito Calzada

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Parsing Json file with Jackson

2 Answers2