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Android HTTP Get to api

I´m trying to get data from my api. In postman the request works, here´s the response:
{
"ips_Beacons_BeaconID": 14,
"ips_Beacons_BeaconDescription": "b2",
"ips_Beacons_BeaconLat": 12.3123,
"ips_Beacons_BeaconLon": 32.123,
"ips_Beacons_BeaconImgX": 45,
"ips_Beacons_BeaconImgY": 123
}
I´ve tried and i got the response with Okhttp. However it stopped working for some reason.
Although i got the response, i wish to serialize the json string it and instanciate objects. But i couldn´t get the response out of the onSuccess method inside the callback.
This is what i had that workd but doens´t work anymore:
OkHttpClient client = new OkHttpClient();
String url ="http://192.168.1.95:44374/api/beacons";
Request request = new Request.Builder().url(url).build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Call call, IOException e) { e.printStackTrace();
}
#Override
public void onResponse(Call call, Response response) throws IOException {
if (response.isSuccessful()){
String myResponse = response.body().string();
listBeacons = objectMapper.readValue(myResponse, new TypeReference<List<Beacon>>(){});
Log.i(TAG, myResponse);
}
}
});
I need the listBeacons List to perform other operations outside this activity.

How to implement custom error handling with retroift2

I calling to the api with the basic retrofit Call object:
public interface dataApi {
#GET("animal/cats")
Call<AllAnimals> getAllData(
#Query("api_key") String apiKey
);
}
And I can get the response inside my view model like this:
call.enqueue(new Callback<AllAnimals>() {
#Override
public void onResponse(Call<AllAnimals> call, Response<AllAnimals> response) {
animals.setValue(response.body());
}
#Override
public void onFailure(Call<AllAnimals> call, Throwable t) {
Log.i(TAG, "onFailure: " + t);
}
});
Nothing speical here.
I've several problem with this approach
FIRST - if I give the wrong api key for example, the response should give me a response with the code of the problem, instead I just get null body.
SECOND I am planning to have more api calls, and it's a huge code duplication to handle errors every call I wrote.
How can I implement custom error handling for this situation, that will be apply to other calls too?

I think you can use okhttp interceptor and define yourself ResponseBody converter to fix your problem.
First,intercept you interested request and response;
Second,check the response,if response is failed then modify the response body to empty。
define a simple interceptor
Interceptor interceptor = new Interceptor() {
#Override
public okhttp3.Response intercept(Chain chain) throws IOException {
Request request = chain.request();
String url = request.url().toString();
System.out.println(request.url());
okhttp3.Response response = chain.proceed(request);
if (!response.isSuccessful() && url.contains("animal/cats")) {
// request failed begin to modify response body
response = response.newBuilder()
.body(ResponseBody.create(MediaType.parse("application/json"), new byte[] {}))
.build();
}
return response;
}
};
define self ResponseBody converter
most code from com.squareup.retrofit2:converter-jackson we just add two lines:
final class JacksonResponseBodyConverter<T> implements Converter<ResponseBody, T> {
private final ObjectReader adapter;
JacksonResponseBodyConverter(ObjectReader adapter) {
this.adapter = adapter;
}
#Override public T convert(ResponseBody value) throws IOException {
try {
if (value.contentLength() == 0) {
return null;
}
return adapter.readValue(value.charStream());
} finally {
value.close();
}
}
}
the below code is added：
if (value.contentLength() == 0) {
return null;
}

Android OkHttp library: GET Request - Exception EOFException: \n not found: size=0 content=

I'm using in my app OkHttp library (http://square.github.io/okhttp/) and in one simple GET request I get this exception:
Caused by: java.io.EOFException: \n not found: size=0 content=...
at okio.RealBufferedSource.readUtf8LineStrict(RealBufferedSource.java:201)
at com.squareup.okhttp.internal.http.HttpConnection.readResponse(HttpConnection.java:191)
...
unexpected end of stream on Connection{th.it-bedna.cz:80, proxy=DIRECT# hostAddress=85.118.128.42 cipherSuite=none protocol=http/1.1} (recycle count=0)
Other Get requests to the same address works OK. And if I type this request to the Chrome it works also OK. Do you know where is a problem?
Thanks for any advice.
Edit: code of the GET
public Call doGetRequest(String url, Callback callback) {
com.squareup.okhttp.Request request = new com.squareup.okhttp.Request.Builder()
.url(url)
.build();
Call call = client.newCall(request);
call.enqueue(callback);
return call;
}
Using:
void getData()
{
String url = "http://th.it-bedna.cz/api/v2/event/1/user?i=8";
Singleton.getInstance().doGetRequest(url, new Callback() {
#Override
public void onFailure(Request request, IOException e) {
Log.i("CDT", "onFailure: " + e);
}
#Override
public void onResponse(Response response) throws IOException {
}
});
}

If your server is th.it-bedna.cz as in your logcat info, you can try the following code:
OkHttpClient client = new OkHttpClient();
// GET request
Request request = new Request.Builder()
.url("http://th.it-bedna.cz")
.build();
client.newCall(request).enqueue(new Callback() {
#Override
public void onFailure(Request request, IOException e) {
Log.e(LOG_TAG, e.toString());
}
#Override
public void onResponse(Response response) throws IOException {
Log.w(LOG_TAG, response.body().string());
Log.i(LOG_TAG, response.toString());
}
});

I had the same issue with OkHttpClient and HttpURLConnection.
My android emulator was configured to use proxy, but my proxy wasn't accepting connections.
Doesn't mater if you use proxy or not if destination host refuses connection you will get that exception.

Change deferredResult HTTP status code on timeout

I am using deferredResult on Spring MVC, but using this code, the timeout still are sending back the HTTP code 503 to the client.
future.onCompletion(new Runnable() {
#Override
public void run() {
if(future.isSetOrExpired()){
response.setStatus(HttpServletResponse.SC_NO_CONTENT);
}
}
});
Any idea what else to try?

I ran into the same issue. My Spring MVC Controller method originally returned DeferredResult<Object>, but then I realised I wanted to control the HTTP status code. I found the answer here:
https://www.jayway.com/2014/09/09/asynchronous-spring-service/
#RequestMapping("/async")
DeferredResult<ResponseEntity<?>> async(#RequestParam("q") String query) {
DeferredResult<ResponseEntity<?>> deferredResult = new DeferredResult<>();
ListenableFuture<RepoListDto> repositoryListDto = repoListService.search(query);
repositoryListDto.addCallback(
new ListenableFutureCallback<RepoListDto>() {
#Override
public void onSuccess(RepoListDto result) {
ResponseEntity<RepoListDto> responseEntity =
new ResponseEntity<>(result, HttpStatus.OK);
deferredResult.setResult(responseEntity);
}
#Override
public void onFailure(Throwable t) {
log.error("Failed to fetch result from remote service", t);
ResponseEntity<Void> responseEntity =
new ResponseEntity<>(HttpStatus.SERVICE_UNAVAILABLE);
deferredResult.setResult(responseEntity);
}
}
);
return deferredResult;
}
Just use DeferredResult<ResponseEntity> and you can set both the response and the Http response code in the ResponseEntity.

Gwt and php rpc

I am using gwt with php.
I am trying to get data fom the http://typing.lc/userInfo.php url.
but the following code returns nothing, but response.getText() is 200, however when i ask http://typing.lc/userInfo.php through browser it returns value.
try
{
RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, "http://typing.lc/userInfo.php");
builder.setHeader("Content-Type", "application/x-www-form-urlencoded");
builder.sendRequest("", new RequestCallback()
{
#Override
public void onError(Request request, Throwable exception)
{
Window.alert("Error");
}
#Override
public void onResponseReceived(Request request, Response response)
{
Window.alert("Success: " + response.getText());
}
});
}
catch (RequestException e)
{
Window.alert("Exception");
}

You are probably running into a SOP (Same Origin Policy) issue.
See here for possible solutions.