Using addHeader() in an interceptor with retrofit doesn't give the right request-CodePudding

I'm trying to use global headers with a headerInterceptor but when I test it, they don't seem to be working. When I use @Headers("Content-Type: application/json") in the apiService, it works. I've followed several tutorials and I can't find any differences in code.

fun getRetrofit(): Retrofit{
return Retrofit.Builder()
    .baseUrl(BASE_URL)
    .client(client)
    .addConverterFactory(GsonConverterFactory.create())
    .build()
}


private val client = OkHttpClient.Builder()
    .addInterceptor(HeaderInterceptor())
    .build()



class HeaderInterceptor : Interceptor {
    override fun intercept(chain: Interceptor.Chain): Response {
        val request = chain.request()
            .newBuilder()
            .addHeader("Content-Type", "application/json")//This doesn't work
            .build()
        return chain.proceed(request)
    }
}

I call getRetrofit() like this, within a coroutine:

val respuesta = getRetrofit().create(KiritoApiService::class.java).requestMyToken(salida).execute()

The related dependencies I'm using are these:

implementation "com.squareup.retrofit2:retrofit:2.9.0"
implementation "com.squareup.retrofit2:converter-gson:2.9.0"
implementation "com.squareup.okhttp3:logging-interceptor:4.5.0"

I've also tried changing .addHeader() for .header() with no success. I've made it work with @Headers() tags in the @POST requests, but I want this to work, as it's more readable and I can make less mistakes. Many thanks in advance!!

Edit: I'm adding the results of the logging interceptor. They are exactly the same, except for the order between "Content-Type" and "Content-Length". I've also ruled that out with another test, so I think the problem isn't in the headers. I dont know what else can I be missing.

Using @headers("Content-Type: application/json") I get the correct answer from the server:

2022-09-23 14:53:29.599 3829-3888/es.kirito.kirito D/OkHttp: --> POST https://kirito.es/chasca/api.php
2022-09-23 14:53:29.599 3829-3888/es.kirito.kirito D/OkHttp: Content-Type: application/json
2022-09-23 14:53:29.599 3829-3888/es.kirito.kirito D/OkHttp: Content-Length: 156
2022-09-23 14:53:29.600 3829-3888/es.kirito.kirito D/OkHttp: {"descripcion_dispositivo":"AOSP on IA Emulator","id_dispositivo":"78b69555b3082d5a","password":"123456","peticion":"usuarios.login","usuario":"1234567"}
2022-09-23 14:53:29.600 3829-3888/es.kirito.kirito D/OkHttp: --> END POST (156-byte body)
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: <-- 200 https://kirito.es/chasca/api.php (120ms)
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: server: nginx
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: date: Fri, 23 Sep 2022 12:53:31 GMT
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: content-type: application/json; charset=utf-8
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: vary: Accept-Encoding
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: set-cookie: a=8a9935e7a5391b78e6cd3948b4331a3e; path=/chasca/
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: content-security-policy: upgrade-insecure-requests;
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: x-frame-options: SAMEORIGIN
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: x-xss-protection: 1; mode=block
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: strict-transport-security: max-age=31536000; includeSubDomains; preload
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: x-xss-protection: 1; mode=block
2022-09-23 14:53:29.720 3829-3888/es.kirito.kirito D/OkHttp: x-content-type-options: nosniff
2022-09-23 14:53:29.721 3829-3888/es.kirito.kirito D/OkHttp: x-server-powered-by: Engintron
2022-09-23 14:53:29.722 3829-3888/es.kirito.kirito D/OkHttp: {"error":{"error":"0","errorCode":"0","errorDesc":"Sin error"},"query":{"fecha":"23-09-2022","hora":"14:53:31","query":"usuarios.login"},"respuesta":{"login":{"id_usuario":"11","token":"eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpZF91c3VhcmlvIjoiMTEiLCJwYXRoX2luc3RhbGFjaW9uIjoiY2hhc2NhIn0=.A2OIiiPdVkuZ82xz4RqpfcA2BChl7Kcv9HIVPwAz9IE="}}}
2022-09-23 14:53:29.722 3829-3888/es.kirito.kirito D/OkHttp: <-- END HTTP (336-byte body)

Using the header interceptor .addHeader("Content-Type", "application/json"):

2022-09-23 15:52:59.650 4133-4182/es.kirito.kirito D/OkHttp: --> POST https://kirito.es/chasca/api.php
2022-09-23 15:52:59.650 4133-4182/es.kirito.kirito D/OkHttp: Content-Length: 156
2022-09-23 15:52:59.650 4133-4182/es.kirito.kirito D/OkHttp: Content-Type: application/json
2022-09-23 15:52:59.651 4133-4182/es.kirito.kirito D/OkHttp: {"descripcion_dispositivo":"AOSP on IA Emulator","id_dispositivo":"78b69555b3082d5a","password":"123456","peticion":"usuarios.login","usuario":"1234567"}
2022-09-23 15:52:59.651 4133-4182/es.kirito.kirito D/OkHttp: --> END POST (156-byte body)
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: <-- 200 https://kirito.es/chasca/api.php (44ms)
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: server: nginx
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: date: Fri, 23 Sep 2022 13:53:01 GMT
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: content-type: application/json; charset=utf-8
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: vary: Accept-Encoding
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: set-cookie: a=dc971fbc6b3f5bf05bab74bc1793da5c; path=/chasca/
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: content-security-policy: upgrade-insecure-requests;
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: x-frame-options: SAMEORIGIN
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: x-xss-protection: 1; mode=block
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: strict-transport-security: max-age=31536000; includeSubDomains; preload
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: x-xss-protection: 1; mode=block
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: x-content-type-options: nosniff
2022-09-23 15:52:59.696 4133-4182/es.kirito.kirito D/OkHttp: x-server-powered-by: Engintron
2022-09-23 15:52:59.697 4133-4182/es.kirito.kirito D/OkHttp: {"error":{"error":"1","errorCode":"3","errorDesc":"Peticion incorrecta"},"query":{"fecha":"23-09-2022","hora":"15:53:01","query":null},"respuesta":null}
2022-09-23 15:52:59.697 4133-4182/es.kirito.kirito D/OkHttp: <-- END HTTP (152-byte body)

Final edit: The problem at the end was on the server side. The slight difference is that when I send the headers with the interceptor, it actually sends "application\json; charset=UTF-8", together, and the server didn't recognise then either of the configurations.

CodePudding user response：

How do you know that it doesn't work? Your code seems legit, but there might be some hidden pitfalls after all.

To narrow down the problem, I would suggest to add a logging interceptor additionally (you already have the depencency):

private val client = OkHttpClient.Builder()
    .addInterceptor(HeaderInterceptor())
    .addInterceptor(HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY))
    .build()

I reproduced your code on my machine and logging shows me that the header is set as it should be:

I/okhttp.OkHttpClient: Content-Type: application/json

This indicates that the problem might not be with the header. Maybe there is something else wrong with your request. As I said, please add the logger interceptor as described above. Maybe you can share this output here for further debugging.