Post request using retrofit

Question

Post request using retrofit

You need to create a POST request with sending a username,password and receiving a token, I was recommended to retrofit, since it can't be done using standard methods. But I don't understand how it creates a request (I looked at the documentation), for example

public interface API { 
   @POST("/v1/registration") 
   Response registerUser(); 
}

But I do not understand at least where the link to the site is and where the request parameters are set. Here I see a request for user registration, but where is all the data? does it take them from the method?

UPD:

   public interface API {
    @POST("/v1/registration")
    Response registerUser(@Body RegistrationBody registrationBody);
    Call<RegistrationResponse> registerUser();
}
public class RegistrationBody{
    public String login;
    public String password;
}
public class RegistrationResponse {
    public String token;
}
Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("https://myserver1.com")
        .build();
API api = retrofit.create(API.class);
@POST("/v1/registration")
Call<RegistrationResponse> registerUser(@Body RegistrationBody registrationBody) {
    return null;
}
Call<RegistrationResponse> call = api.registerUser();
call.enqueue(new Callback<RegistrationResponse() {
    @Override
    public void onResponse(Response<RegistrationResponse> response) {
        if (response.isSuccess()) {
            // tasks available
        } else {
            // error response, no access to resource?
        }
    }

Yes errors starting with call. enqueue

8

android java android-studio httpurlconnection retrofit

Author: Slava Nenashev, 2016-02-17

Source

1 answers

score 25 · Accepted Answer

For example, we have a server with a POST registration method - https://myserver1.com/v1/registration

For example this method accepts Json of the form:

{
  "logins": "ttt",
  "password": "123"
}

And returns a response of the form

{
    "token":"someToken"
}

Then in the project, you need to define an interface that describes this server method in this way

public interface API { 
   @POST("/v1/registration") 
   RegistrationResponse registerUser(@Body RegistrationBody registrationBody); 
}

Where RegistrationBody and RegistrationResponse are classes with the following fields:

public class RegistrationBody{
    public String login;
    public String password;
}

public class RegistrationResponse {
    public String token;
}

Next, to access the server, you first need to create an object Retrofit where to pass the name to servers and any other additional information.

Retrofit retrofit = Retrofit.Builder()
                .baseUrl("https://myserver1.com")
                .build();

Then, from this object, you can get the implementation of the interface with the methods

API api = retrofit.create(API.class);

And then call the necessary methods for the object api. Just remember that you can not go to the Internet in the main stream. To make the request to the server in a separate thread, you can use the tools that Retrofit provides. To do this, wrap the returned parameter in the interface in the type Call

@POST("/v1/registration") 
Call<RegistrationResponse> registerUser(@Body RegistrationBody registrationBody);

And then call

Call<RegistrationResponse> call = api.registerUser(...);
call.enqueue(new Callback<RegistrationResponse() {  
    @Override
    public void onResponse(Response<RegistrationResponse> response) {
        if (response.isSuccess()) {
            // tasks available
        } else {
            // error response, no access to resource?
        }
    }

    @Override
    public void onFailure(Throwable t) {
    }
}

UPD: In the api.registerUser(...) method, you must pass the object RegistrationBody after filling it with data:

RegistrationBody body = new RegistrationBody();
body.login = "myLogin";
body.password = "12345";

api.registerUser(body);

Serialization takes place using the GSON library. To learn how to properly serialize an object, read the official documentation.

To work in asynchronous mode, simply create a method in the API interface that will return Call<T> instead of T