Receiving error "Expected BEGIN_ARRAY but was BEGIN_OBJECT"

Question

I have this problem and cant seem to find a solution. I have Googled around but to no avail.

The API is returning an array of objects but gson has found an object.

My Model

public class Message {

private int id;
private String title;
private String details;  }

MessageClient

public interface MessageClient {

@GET("/api/test")
Call<List<Message>> getMessages();}

Implementation

Retrofit.Builder builder = new Retrofit.Builder()
            .baseUrl(Api.BASE_URL)
            .client(okHttpClient)
            .addConverterFactory(GsonConverterFactory.create());
    Retrofit retrofit = builder.build();

MessageClient client =  retrofit.create(MessageClient.class);
Call<List<Message>> call = client.getMessages();

call.enqueue(new Callback<List<Message>>() {
    @Override
    public void onResponse(Call<List<Message>> call, Response<List<Message>> response) {
        List<Message> messageList = response.body();
        Log.d(TAG, "LIST: "+messageList);
    }

    @Override
    public void onFailure(Call<List<Message>> call, Throwable t) {
        Log.d(TAG, "API ERROR: "+t.getMessage());
    }
});

Sample data from API

[
{
    "id": 1,
    "title": "Title 1",
    "details": "Message1.",
    "client_id": 1,

},
{
    "id": 2,
    "title": "Title 2",
    "details": "Message 2.",
    "client_id": 1,
}]

Where am I missing it? Please note the API sample data.

Also, note that recent versions of Retrofit make it very easy to log the raw HTTP conversation. — , Sep 15 '17 at 21:20
I am getting this error **Expected BEGIN_ARRAY but was BEGIN_OBJECT at line 1 column 2 path $** — FreddCha, Sep 15 '17 at 21:21
Please update the question with these details (Also, **where** are you seeing this error, and **when**?). Anyway, you are giving it an object, not an array. See: https://stackoverflow.com/q/36177629/1531971 — , Sep 15 '17 at 21:22
But from the sample data I provided, the API is returning an array of objects so I cant seem to understand this error, please help and be patient I am a bit new to programming — FreddCha, Sep 15 '17 at 21:32
You should try and understand the dup I found. It is almost certainly the same problem. — , Sep 15 '17 at 23:28
*cant seem to find a solution. I have Googled around but to no avail* what exactly are you googling? There are a million questions about this already, I don't believe you didn't find any of them — Tim, Sep 18 '17 at 09:42

ninjayoto · Answer 1 · 2017-09-19T07:44:29.167

Yes, the API is not returning one message, it is returning an array of messages. So you need to map it as a list, not as a single message.

So I suggest that: 1. You create an additional model, bean or pojo. You can call it MessageList, and it would look something like:

public class MessagesList {
  private List<Message> messageList;
//add getters and setters .. etc.
}

I think you should also change List<Message> in your code to MessageList instead.

This should allow the list of messages returned by the API to be mapped to the MessageList model, each individual message will be mapped to a Message object with it's (unique?) id, title and details. And you are able now to iterate through the list to get each Message.

Good luck

Thank you for you suggestion. But I realized that the code is ok as it is, only that I was using a wrong API url. — FreddCha, Sep 19 '17 at 11:59

Receiving error "Expected BEGIN_ARRAY but was BEGIN_OBJECT"

1 Answers1