Develop Reference

Retrofit "form-urlencoded" request with #Field-annotated parameter

I have two queries:
#POST("/auth/login")
suspend fun login(#Body user: LoginUserDto): AuthResponse<TokenDto>
#FormUrlEncoded
#POST("/auth/refresh")
suspend fun refreshToken(#Field("refreshtoken") refreshToken: String): AuthResponse<TokenDto>
The first one is working well which means baseUrl is OK.
The second one returns HTTP 404 Not Found. WHen I look at Chucker interceptor logs, the url is correct and the refreshToken is present in the request. When I try to trigger it manually from request.rest in vsCode like this:
POST http://localhost:4000/auth/refresh/eyJhbGciOiJIUzI1NiIsInR5...blablabla
... it works fine.
The code of the endpoint starts like this (node.js server):
app.post('/auth/refresh/:refreshtoken', async (req, res) => {
const refreshToken = req.params.refreshtoken;
// some code
I believe I made mistake in my retrofit call refreshToken(#Field("refreshtoken") refreshToken: String).
Could smb help how make such #FormUrlEncoded request with retrofit properly?
Appreciate any help.

#Field is used to send #FormUrlEncoded request in Retrofit which hides your parameter and not attach with url to provide security.Used for POST request.
#Query parameter appended to the URL.
If you are using #Field request than it will hides your parameter and not append with the url.
If you are using #Query request than all your parameter is append to your request and visible to users.
Depend on your api request you have to use one of above annotation. If the api request accept the #FormUrlEncoded data than use #Field or if they want to attached it with url than use #Query.

How to send request body in get method retrofit

I am using the retrofit library for network calls. In this, I need to pass Body in GET Method. But I am getting the error while I am passing this one. In Postman it is working while passing Body for GET Method.
#GET("http://192.168.0.141:3000/api/contacts/{page_num}/{limit}")
fun getAllContacts(#Path("page_num") page_num:Int,#Path("limit") limit:Int,#Body reqBody:ContactsInpRequest):Call<AllContactsDataResponse>
I am calling get method by passing body. But I am getting the below exception.
java.lang.IllegalArgumentException: Non-body HTTP method cannot contain #Body.

GET method does not contain body like the POST does. Here you can learn more about REST methods: https://restfulapi.net/http-methods/
EDIT: I see that you said that it works in Postman so take a look at this:
*CAN GET request have a body?
In other words, any HTTP request message is allowed to contain a message body, and thus must parse messages with that in mind. Server semantics for GET, however, are restricted such that a body, if any, has no semantic meaning to the request. ... Yes, you can send a request body with GET but it should not have any meaning.*

java.lang.IllegalArgumentException: Non-body HTTP method cannot contain #Body
This means your #GET or #DELETE should not have #Body parameter. You can use query type url or path type url or Query Map to fulfill your need. Else you can use other method annotation.

#Headers("Content-Type: application/json")
#GET("helper-url")
fun getHelperUrl(
#Query("api_token") apiToken: String,
#Query("authtype") authType: String,
#Query("channel") channel: String
): Call<ResponseHelperUrl>

What is the difference between #Field and #Query in retrofit

In some POST requests, I don't know when to use #Field with FormUrlEncoded and when to use #Query
For Example:
#POST("list-products-for-sale")
Call<ListAllProductsResponse> getNewProducts(#HeaderMap Map<String,
String> headers,#Query("lastProductId") String lastProductId);
When I tried to use #Field here it was not responding properly and when I switched it to #Query it's working great.
I want to know why #Field isn't working while Query can work perfectly and I did tested in POSTMAN where I sent the data as a formurlencoded and it's giving me the results fin.
EDIT
BTW I'm passing Content-Type:application/json, Accept: application/json with an Authorization key

#Field is used to send #FormUrlEncoded request in Retrofit which hides your parameter and not attach with url to provide security.Used for POST request.
#Query parameter appended to the URL.
If you are using #Field request than it will hides your parameter and not append with the url.
If you are using #Query request than all your parameter is append to your request and visible to users.
Depend on your api request you have to use one of above annotation. If the api request accept the #FormUrlEncoded data than use #Field or if they want to attached it with url than use #Query.
You can get more information from below link :
1) https://square.github.io/retrofit/2.x/retrofit/index.html?retrofit2/http/Query.html
2) https://square.github.io/retrofit/2.x/retrofit/retrofit2/http/Field.html

Adding dynamic header to POST request with body (Retrofit v2.4.0)

I am using Retrofit v2.4.0 in my project. I need to get token using one API call and using this token in header of the POST request I should use another API call where I should add one header and two parameter to the body of the request. The following code is of the second API call (JavaRx is used):
#FormUrlEncoded
#POST("auth/sendCode")
#Headers("Content-Type: application/json")
Single<SendCodeResponse> sendCode(#Header("token") String token,
#Field("phoneNumber") String phoneNumber,
#Field("langCode") String langCode);
However, it is not working. When I log my request, it is showing that the request body is not correct.
What is wrong with my code above?

Using #Path and #Url paramers together with retrofit2

I'm using retrofit2 to comunicate with a webapi.
I need to set the URL of the webapi dynamically beacuase the user can change it, so i use the #Url annotation to specify it like this:
#POST
Call<LoginResponse> login(#Url String url, #Body LoginRequest user);
In one of the operations, i need to send some path parameters to the server, so i do this:
#GET
Call<DataResponse> getOrder(#Url String url,
#Header(WEBAPI_EMAIL_HEDER) String email,
#Header(WEBAPI_TOKEN_ID_HEDER) String token,
#Path("id") int id);
When i call the operation getOrder(...), an exception is rised by retrofit because i am not suppoused to use #Url and #Path parameters in the same operation.
This is the exception:
java.lang.IllegalArgumentException: #Path parameters may not be used with #Url. (parameter #4)
One solution is to replace the id parameter on the url and use only the #Url parameter in the invokation. But i think this is not the best way, beacuase i will be doing this with all the operations with #Path parameters.
Is there any other cleaner solution? Maybe using another retrofit2 annotation?
Thanks in advance.

As described in the post Retrofit 2 - Dynamic URL, the #Url notation assumes that the String is a fully defined URL and does not check whether it contains #Path variables.
To use the #Path annotation, you have to configure an endpoint URL and include the #Path variable inside the #GET() annotation.

There is a workaround. Incase of a dynamic Url with some variable path, we can define a string format with paths denoted by %s arguments.
E.g:
Suppose the dynamic url with path is : https://www.example.com/users/{id}/whoami
Here we can just replace {id} with %s. So now it becomes,
val formatString = https://www.example.com/users/%s/whoami
Now we can use it as a format string and replace it with required id.
val url = formatString.format(id)
and in the retrofit interface, use #Url parameter in the function.
interface AnyService {
fun whoAmI(#Url url:String): Call<ResponseBody>
}
Incase you are using MVVM architecture, you can call the formatting code in the concerned repository.