Deserialize an object with children

Question

I have a Json list using object with children

{
 "id":"154",
 "name":"peter",
 "children": [
               {
                "id":"122",
                "name": "mick",
                "children":[]
               },
               {
                "id":"123",
                "name": "mick",
                "children":[]
               }
            ]
}

Here is the class of my object:

public class person{
                    private String id;
                    private String name;
                    private List<person> children;

//getters and setters
}

When I try to deserialize this object, I have the following error

Can not deserialize instance of person out of START_ARRAY token

What should I do ?

https://stackoverflow.com/questions/19333106/jsonmappingexception-out-of-start-array-token — Naveen Yadav, Apr 30 '18 at 09:35
Thanks for your help The Json I receive is OK and cannot be changed. I might have rewritten it with some mistakes though. — Jean, Apr 30 '18 at 09:52

score 1 · Answer 1 · answered Apr 30 '18 at 09:42

The JSON contains an array of persons. Your class a List of person.

Either change the JSON like @Naveed Yadav suggested or change the class to

public class Person{
             private String id;
             private String name;
             private Person[] children;

//getters and setters
}

(BTW the class name should be upper case in Java)

score 1 · Answer 2 · answered Apr 30 '18 at 09:55

Fix syntax errors in your JSON body and you'll be in a good shape:

{
 "id":"154",
 "name":"peter",
 "children": [
               {
                "id":"122",
                "name": "mick",
                "children":[], <== Excess comma
               } <== Missing comma 
               {
                "id":"123",
                "name": "mick",
                "children":[], <== Excess comma
               }
            ]
}

Valid one:

{
    "id": "154",
    "name": "peter",
    "children": [{
            "id": "122",
            "name": "mick",
            "children": []
        },
        {
            "id": "123",
            "name": "mick",
            "children": []
        }
    ]
}

score 0 · Answer 3 · answered Apr 30 '18 at 09:44

You need to change your POJO declaration like below:-

 public class person{
                private String id;
                private String name;
                private List<Children> children;

               //getters and setters

   private class Children{
                private String id;
                private String name;
                private String[] children;

}

score -1 · Answer 4 · answered Apr 30 '18 at 09:36

-1

{
 "id":"154",
 "name":"peter",
 "children": 
               {
                "id":"122",
                "name": "mick",
                "children":[],
               }
               {
                "id":"123",
                "name": "mick",
                "children":[],
               }

}

answered Apr 30 '18 at 09:36

Naveen Yadav

203
9
25

or change to `private person[] children;` – Datz Apr 30 '18 at 09:40

Deserialize an object with children

4 Answers4