Retrofit2 OkHttp3响应正文Null错误

Question

我正在使用reverfit2调用一个微服务，它在PUT方法上返回一个200和一个空的响应体。但是，reverfit 2似乎无法处理这一点，并且在“enqueue”中转到onFailure分支
@override public void onFailure（Call Call,Throwable t）{

以下是日志：

Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: --> PUT http://127.0.0.1/test/ http/1.1
Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: Content-Type: application/vnd.tipico.notification-v1+json
Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: Content-Length: 87
Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: 
Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: {"state":"ACTIVE","externalId":"abcd","loginName":"gsdfgsdf","updatedAt":1495531062000}
Mai 27, 2017 3:26:49 PM okhttp3.internal.platform.Platform log
INFORMATION: --> END PUT (87-byte body)
Mai 27, 2017 3:26:50 PM okhttp3.internal.platform.Platform log
INFORMATION: <-- 200  http://127.0.0.1/test/ (197ms)
Mai 27, 2017 3:26:50 PM okhttp3.internal.platform.Platform log
INFORMATION: X-Application-Context: customer-care-notification-service:49980
Mai 27, 2017 3:26:50 PM okhttp3.internal.platform.Platform log
INFORMATION: Content-Length: 0
Mai 27, 2017 3:26:50 PM okhttp3.internal.platform.Platform log
INFORMATION: Date: Sat, 27 May 2017 13:26:49 GMT
Mai 27, 2017 3:26:50 PM okhttp3.internal.platform.Platform log
INFORMATION: <-- END HTTP (0-byte body)
15:26:50,030 ERROR com.test.app.Test - Failed CCNS call com.fasterxml.jackson.databind.JsonMappingException: No content to map due to end-of-input
 at [Source: okhttp3.ResponseBody$BomAwareReader@9eb187b; line: 1, column: 0]

有人知道这是什么原因造成的吗？因为请求被成功地提供了（见上文）。

Answer 1

我为此问题创建了一个空处理程序转换器：

public class NullOnEmptyConverterFactory extends Converter.Factory {

    @Override
    public Converter<ResponseBody, ?> responseBodyConverter(Type type, Annotation[] annotations, Retrofit retrofit) {
        final Converter<ResponseBody, ?> delegate = retrofit.nextResponseBodyConverter(this, type, annotations);
        return (Converter<ResponseBody, Object>) body -> {
            if (body.contentLength() == 0) return null;
            return delegate.convert(body);
        };
    }
}

您需要在Gson转换器之前添加此转换器

.addConverterFactory(new NullOnEmptyConverterFactory())