List of JsonString to list of User Objects conversion [duplicate]

Question

Not the duplicate of How to use Jackson to deserialise an array of objects.

Here in the list ,items are string within double quotes.

I am trying to convert a list of messages which are jsonString to List of UserDefined objects. I have input like this.

[
    "{\"id\":\"5\",\"type\":\"abc\",\"innerObject\":{\"id\":\"8\"}}"
]

What is the method to convert this list to List of MyClass.

class MyClass{
String id;
String type;
Inner inner;
//getters and setters
}
class Inner{
String id;
//getters and setters
}

I have tried

objectMapper.readValue(jsonFormattedString, new TypeReference<List<MyClass>>(){});

Also this

Type listType = new TypeToken<ArrayList<MyClass>>() {}.getType();
myList = new Gson().fromJson(jsonFormattedString, listType);

But not working.

Expected output is

[{"id":"5","type":"abc","innerObject":"8"}]

Answer 1

For the readValue method of ObjectMapper, the second argument should be the class and not a class instance. For example, if this were a single item you would call readValue as shown below:

objectMapper.readValue(jsonFormattedString, TransEvent.class);

For a generic list, this can be accomplished either of the following ways:

// list
objectMapper.readValue(jsonFormattedString, new TypeReference<List<TransEvent>>(){});

// list
objectMapper.readValue(jsonFormattedString, objectMapper.getTypeFactory().constructCollectionType(List.class, TransEvent.class));

// array
TransEvent[] transEvents = objectMapper.readValue(jsonFormattedString, TransEvent[].class);