Convert json array string to java object using jackson API

Question

I have JSON string like below, and want to convert into Java object using jackson API.

 [
      {
        "Users": {
          "id": "1",
          "userId": "1424",
          "Firstname": "lms",

        }
      },
      {
        "Users": {
          "id": "2",
          "userId": "4527",
          "Firstname": "Matthew",
         }
      }
 ]

Can you please help me out.

e.g. http://stackoverflow.com/questions/17371134/java-json-parsing-with-jackson — Scary Wombat, Dec 06 '16 at 07:30
Possible duplicate of [How to use Jackson to deserialise an array of objects](http://stackoverflow.com/questions/6349421/how-to-use-jackson-to-deserialise-an-array-of-objects) — PMerlet, Dec 06 '16 at 07:30
I googled out and found the answer. Thanks all for help!! http://stackoverflow.com/questions/19333106/jsonmappingexception-out-of-start-array-token — Ankur jain, Dec 06 '16 at 07:50

score 0 · Accepted Answer · answered Dec 06 '16 at 07:53

This is the solution, works like charm:

try {
                TypeFactory typeFactory = mapper.getTypeFactory();
                CollectionType collectionType = typeFactory.constructCollectionType(
                                                    List.class, Users.class);
                List<Users> usersList =  mapper.readValue(new File("list.json"), collectionType);     

            } catch (IOException e) {
                e.printStackTrace();
            }

score -1 · Answer 2 · answered Dec 06 '16 at 07:35

-1

Google is your friend, this example shows a good demo

ObjectMapper mapper = new ObjectMapper();
String jsonInString = "{'name' : 'mkyong'}";

//JSON from String to Object
User user = mapper.readValue(jsonInString, User.class);

answered Dec 06 '16 at 07:35

Jerry

98
1
9

This is for single object. But in my case i have array. Please Do let me know how to convert array into java object – Ankur jain Dec 06 '16 at 07:36
Guess @Cubi has pointed out the solution for you then – Jerry Dec 06 '16 at 07:43

Convert json array string to java object using jackson API

2 Answers2