改造-获取空错误响应正文（MalformedJsonException）

Question

I'm trying to get error response body in onFailure(RetrofitError error) , but getting null .

I am using the header Accept: text/plain for requests and from response I receive Content-Type: text/plain and can see body as text if I set LogLevel.FULL . Moreover, error.getResponse().getStatus() gives me correct status code.

But when I perform error.getBody() or error.getResponse.getBody() it returns null . Inside error I see that successType is java.lang.String , so I assume it should give me String , but error.getCause() shows me

com.google.gson.JsonSyntaxException: com.google.gson.stream.MalformedJsonException: Use JsonReader.setLenient(true) to accept malformed JSON at line 1 column 6 path $

Also, error.getKind() is CONVERSION , which stands for

/** An exception was thrown while (de)serializing a body. */

but I expect to get kind as HTTP

Question is why does it tries to convert into JSON when all headers are using text/plain and successType is String ? I need to get my response as plain text.

Code snippet:

RestAdapter restAdapter = new RestAdapter.Builder()
        .setEndpoint(url)
        .setLogLevel(RestAdapter.LogLevel.FULL)
        .setClient(new CustomOkHttpClient())
        .setRequestInterceptor(new TransactionsRequestInterceptor())
        .build();

TransactionsRestClient httpClient = restAdapter.create(TransactionsRestClient.class);
httpClient.createNewTransaction(request, new retrofit.Callback<String>() {
    @Override
    public void success(String transactionId, Response response) {

    }

    @Override
    public void failure(RetrofitError error) {
        // error.getBody() is null
    }
}
public interface TransactionsRestClient {
    @POST("/transactions")
    void createNewTransaction(@Body TransactionRequest request, Callback<String> transactionId);
}

public class TransactionsRequestInterceptor implements RequestInterceptor {
    @Override
    public void intercept(RequestFacade request) {
        request.addHeader(HOST, host);
        request.addHeader(TOKEN, token);
        request.addHeader(ACCEPT, TEXT);
        request.addHeader(CONTENT_TYPE, JSON);
    }

Logged requests/responses:

 ---> HTTP POST $url
Host: $host
Accept: text/plain
Content-Type: application/json
Content-Length: 133
$request_body
---> END HTTP (133-byte body)

<--- HTTP 202 $url //202 is expected
Access-Control-Allow-Origin:
Content-Type: text/plain
Date: Wed, 20 May 2015 16:08:46 GMT
Server: spray-can/1.3.1
Content-Length: 50
Connection: keep-alive
OkHttp-Selected-Protocol: http/1.1
OkHttp-Sent-Millis: 1432138139875
OkHttp-Received-Millis: 1432138140004
The record for test10 is not currently authorized. // this is body I have to get
<--- END HTTP (50-byte body)

Thanks.

Answer 1

By default Retrofit reads the response as a JSON and parses it automatically. You have to change it's default behavior.

This blog post might be helpful, and suggests you to get your String response as:

new String(((TypedByteArray) response.getBody()).getBytes());

Answer 2

In your code new RestAdapter.Builder() you do not specify a Converter ( setConverter() ).

Looking at Retrofit code, more specifically at RestAdapter and Platform I checked that if you do not specify a Converter it will use GSON as default:

@Override Converter defaultConverter() {
  return new GsonConverter(new Gson());
}

I believe the solution is to create a Custom Converter (extending Converter class) and do nothing with your response, just returning the raw String.

Here 's an example on how to create your own Converter.