FiiPractic 2015 - Adroid Pro - Day 3 - API Day

1. Android Pro
API Day

2. – Test Android
“Aplicatia ta foloseste un API (lastfm), sa
spunem ca in format JSON. Cum procedezi sa
consumi aceste date?”

3. Http?
REST?

4. Request + Raspuns
[Header]+[Body] ——URL—> [Server]
[Header]+[Body] <————— [Server]
^JSON

5. Exemplu
http://rest-service.guides.spring.io/greeting
{
"content": "Hello, World!",
"id": 3123
}

6. JSON?
JSONObject jObj = new JSONObject(data);
Greeting greeting = new Greeting();
greeting.content = jObj.getString(“content");
greeting.id = jObj.getLong("id");

7. Http?
HttpClient httpclient = new DefaultHttpClient();
HttpResponse response = httpclient.execute(new HttpGet(URL));
ByteArrayOutputStream out = new ByteArrayOutputStream();
response.getEntity().writeTo(out);
responseString = out.toString();
out.close();

8. Gson
class Greeting{
String content;
long id;
}
Gson gson = new Gson();
Greeting greeting = gson.fromJson(response, Greeting.class);

9. Jackson
class Greeting{
String content;
long id;
}
ObjectMapper mapper = new ObjectMapper();
Greeting greeting = mapper.readValue(responseString, Greeting.class);

10. Retrofit
interface GreetService {
@GET("/greeting")
Greeting getGreeting();
@GET("/altceva")
Altceva getAltceva();
}
RestAdapter restAdapter = new RestAdapter.Builder()
.setServer("http://rest-service.guides.spring.io")
.build();
GreetService greetService = restAdapter.create(GreetService.class);

11. Retrofit
parametri
http://rest-service.guides.spring.io/greeting?name=Bob
public interface GreetService {
@GET("/greeting")
Greeting getGreeting(@Query(“name") String name);
}

12. Retrofit
Async
public interface GreetService {
@GET("/greeting")
void getGreeting(@Query("name") name, Callback<Greeting>
callback);
}

13. Retrofit
@GET, @POST, @PUT, @DELETE, @HEAD
@Query, @Path, @Body, @Header
@Headers
…

14. Spring Android
RestTemplate restTemplate = new RestTemplate();
restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());
Greeting greeting = restTemplate.getForObject(url, Greeting.class);

15. Feign
interface GreetService {
@GET("/greeting")
Greeting getGreeting();
}
GS gs = Feign.builder()
.decoder(new GsonDecoder())
.target(GreetService.class, “https://…");
gs.getGreeting();

16. Volley, Retrofit, Ion (koush) si alte librarii
similare trateaza mai mult partea de networking decat
cea de REST si discutam la cursul 4 despre toate.

17. Work

18. Level 1:
- Incarcati greeting de pe: http://rest-
service.guides.spring.io/greeting
Level 2:
- Faceti un consumator pentru GitHub, Flickr sau LastFM.
- Implementati autentificarea pentru serviciul ales (Nu ma refer la un
ecran de login, hardcodati credentialele)
Level badass:
- Consumati un serviciu pe format XML
- Folositi adnotari Jackson ca sa aveti un denumiri diferite in POJO
fata de JSON
- Extra bonus la tabla, referitor la cast automat.