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When I use retrofit2, the app is just shut down

I used retrofit2 to call API. But, when I called it, my app was just shut down. There are not errors in the Logcat. I googled it, but there is not a solution.
And Retrofit2 and converter-gson version is 2.9.0. I set internet permission in AndroidManifest.xml
MainActivity.kt
private fun loadMembers() {
val retrofit = Retrofit.Builder()
.baseUrl(MemberAPI.base_domain)
.addConverterFactory(GsonConverterFactory.create())
.build()
val retrofitService = retrofit.create(MemberInterface::class.java)
retrofitService
.getMember(Constants.api_key)
.enqueue(object: Callback<Member> {
override fun onResponse(call: Call<Member>, response: Response<Member>) {
val members = response.body() as Member
var names = ""
for (member in members.response.body.items.item) {
names += "\n${member.empNm}"
}
binding.text.text = names
}
override fun onFailure(call: Call<Member>, t: Throwable) {
Toast.makeText(baseContext, "실패", Toast.LENGTH_LONG).show()
}
})
}
Interface.kt
interface MemberInterface {
#GET("{api_key}&numOfRows=5&pageNo=1&_type=json")
fun getMember(#Path("api_key") Key: String): Call<Member>
}
Youtube
Video

Try to add an interceptor so you can see all calls logs (headers, body, URLs, etc...). The crash could be related with the parse of the JSON response to the object Member.
Add OkHtpp to your grade dependencies:
implementation "com.squareup.okhttp3:okhttp:5.0.0-alpha.2"
implementation "com.squareup.okhttp3:logging-interceptor:5.0.0-alpha.2"
And after that, when you create your Retrofit instance, add the interceptor, should look something like this:
val httpClient = OkHttpClient.Builder()
val interceptor = HttpLoggingInterceptor()
interceptor.setLevel(HttpLoggingInterceptor.Level.BODY)
httpClient.addInterceptor(interceptor)
httpClient.addInterceptor(Interceptor { chain: Interceptor.Chain ->
val original: Request = chain.request()
val request: Request = original.newBuilder()
.header("Content-Type", "application/json")
.method(original.method, original.body)
.build()
chain.proceed(request)
})
val okHttpClient = httpClient.build()
val retrofit = Retrofit.Builder()
.baseUrl(MemberAPI.base_domain)
.client(okHttpClient)
.addConverterFactory(GsonConverterFactory.create())
.build()

Retrofit response is always null

I'm trying to get user name from gitHub Api but retrofit response return always null. When I'm trying to show user name in toast I see : null. I tried change retrofit path but it didn't work. Everything looks fine but I don't know why I get this error all the time.
interface GitHubApi{
#GET("/users/{user}")
fun getUser(#Path("user") user: String): Call<User>
companion object Factory {
fun getClient(): GitHubApi {
val url = "https://api.github.com/"
val interceptor = HttpLoggingInterceptor()
.apply { level = HttpLoggingInterceptor.Level.BODY }
val okHttpClient = OkHttpClient.Builder()
.addInterceptor(interceptor)
.build()
val retrofit = Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.client(okHttpClient)
.build()
return retrofit.create(GitHubApi::class.java)
}
}}
user model:
data class User(val userName: String)
MainActivity:
private fun createApiService() : GitHubApi{
val url = "https://api.github.com/"
val interceptor = HttpLoggingInterceptor()
.apply { level = HttpLoggingInterceptor.Level.BODY }
val okHttpClient = OkHttpClient.Builder()
.addInterceptor(interceptor)
.build()
val retrofit = Retrofit.Builder()
.baseUrl(url)
.addConverterFactory(GsonConverterFactory.create())
.client(okHttpClient)
.build()
return retrofit.create(GitHubApi::class.java)
}
private fun loadData() {
val api = GitHubApi.getClient()
api.getUser("fabpot").enqueue(object : Callback<User> {
override fun onFailure(call: Call<User>, t: Throwable) {
t.printStackTrace()
}
override fun onResponse(
call: Call<User>,
response: Response<User>
) {
if (!response.isSuccessful) {
runOnUiThread { showErrorMessage(response.code().toString()) }
}
response.body()?.let { showErrorMessage(it.repoName) }
}
})
}

There is no key userName exist in github api.
try editing your data class this way.
data class User(val name: String)

Try removing the beginning slash "/" in your #GET method.

Retrofit Interceptor not adding query param to URL

I'm trying to add apikey in the URL using custom interceptor but it's not adding the params in the URL so response body is null.
CustomInterceptor
class CustomInterceptor : Interceptor {
override fun intercept(chain: Interceptor.Chain): Response {
val url = chain.request().url().newBuilder()
.addQueryParameter("apiKey", API_KEY)
.build()
val request = chain.request().newBuilder()
.url(url)
.build()
return chain.proceed(request)
}
}
Client
class Client {
companion object {
const val API_KEY = "123123"
private const val apiUrl = "https://www.omdbapi.com/"
fun <T> create(service: Class<T>): T {
val client = OkHttpClient.Builder()
.addInterceptor(CustomInterceptor())
.build()
return Retrofit.Builder()
.baseUrl(apiUrl)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build()
.create(service)
}
}
}
IMovie
interface IMovie {
#GET("/")
fun searchMovie(#Query("s") query: String): Call<SearchResult>
}
After sending the request the response body is null and this is the
Actual URL:- https://www.omdbapi.com/?s=Man
Expected URL:- https://www.omdbapi.com/?s=Man&apikey=123123

First create a new httpUrl instance from the existing request adding your query parameter and value:
var request = chain.request()
val httpUrl = request.url().newBuilder().addQueryParameter("token", authToken).build()
Then update the request:
request = request.newBuilder().url(httpUrl).build()
and proceed with it:
return chain.proceed(request)
When you recall the request from the chain (the one you proceed with after manipulation) you are getting the unmodified request again.

How to use enque method in retrofit in Kotlin android

I am trying to get a response from web service using retrofit and kotlin language. but i am unable to call enque method .
This is retrofit client
class WebService() {
companion object {
fun createService(isAddToken: Boolean): WebServiceApi {
val logging = HttpLoggingInterceptor()
val httpClient = OkHttpClient.Builder()
var retrofit: Retrofit
httpClient.addInterceptor { chain ->
val original = chain.request()
val requestBuilder = original.newBuilder()
.header(CONTENT_TYPE, "application/json")
.header(API_USER_NAME, AUTH_USERNAME)
.header(API_PASSWORD, AUTH_PASSWORD)
.header(LANGUAGE_CODE, "en")
if (isAddToken) {
requestBuilder.header(TOKEN,
"" /*DataGenerator.getAuthToken(context)*/)
}
requestBuilder.method(original.method(), original.body())
val request = requestBuilder.build()
chain.proceed(request)
}
// set your desired log level
if (BuildConfig.DEBUG) {
logging.level = HttpLoggingInterceptor.Level.BODY
// add logging as last interceptor
httpClient.addInterceptor(logging)
}
// Timeout handling
val client = httpClient.readTimeout(20,
TimeUnit.SECONDS)
.connectTimeout(20, TimeUnit.SECONDS)
.writeTimeout(20, TimeUnit.SECONDS)
.build()
if (BuildConfig.DEBUG) {
retrofit = Retrofit.Builder()
.baseUrl(WebServiceConstants.LIVE_BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build()
} else {
retrofit = Retrofit.Builder()
.baseUrl(WebServiceConstants.LIVE_BASE_URL)
.addConverterFactory(GsonConverterFactory.create())
.client(client)
.build()
}
return retrofit.create(WebServiceApi::class.java);
}
}
}
This is code of MainActivity where i am calling api on button
val parameterOTP = SendParameterOTP()
parameterOTP.phoneNumber = phoneNumber
var serviceAPI = WebService.createService(false)
serviceAPI.enque() \\Unable to understand how i call enques**
I tried example using rxjava ,it works fine .But i want to use enque method as i want to implement custom callback for retrying . Please help

try to use this:
val call = createService(isAddToken).methodNameInWebServiceApi(params)
call.enqueue(object : Callback<ResponseObject> {
override fun onFailure(call: Call<ResponseObject>?, t: Throwable?) {
Log.e("erroe", "")
}
override fun onResponse(call: Call<ResponseObject>?, response: Response<ResponseObject>?) {
}
})

i am provide retrofit class and api call using kotlin and make changes according to rxjava in your side.
class ApiClient {
companion object {
val BASE_URL = "https://simplifiedcoding.net/demos/"
var retrofit: Retrofit? = null
fun getClient(): Retrofit? {
if (retrofit == null) {
val interceptor = HttpLoggingInterceptor()
interceptor.level = HttpLoggingInterceptor.Level.BODY
val client = OkHttpClient.Builder().apply {
readTimeout(20, TimeUnit.SECONDS)
writeTimeout(20, TimeUnit.SECONDS)
connectTimeout(20, TimeUnit.SECONDS)
addInterceptor(interceptor)
addInterceptor { chain ->
var request = chain.request()
request = request.newBuilder()
.build()
val response = chain.proceed(request)
response
}
}
retrofit = Retrofit.Builder()
.baseUrl(BASE_URL)
.client(client.build())
.addConverterFactory(GsonConverterFactory.create())
.build()
}
return retrofit
}
}
}
then after used below code for api calling ..
var apiInterface: ApiInterface = ApiClient.getClient()!!.create(ApiInterface::class.java)
var hero: Call<List<Hero>>
hero = apiInterface.getData()
hero.enqueue(object : Callback<List<Hero>> {
override fun onFailure(call: Call<List<Hero>>?, t: Throwable?) {
closeDialog(dialog)
Toast.makeText(mContext, t?.message, Toast.LENGTH_SHORT).show()
Log.d("Error:::",t?.message)
}
override fun onResponse(call: Call<List<Hero>>?, response: Response<List<Hero>>?) {
mHeroDataList.clear()
if (response != null && response.isSuccessful && response.body() != null) {
closeDialog(dialog)
mHeroDataList .addAll(response.body()!!)
setAdapter(mHeroDataList)
}
}
})

app > build.gradle
// Retrofit
implementation ("com.squareup.retrofit2:retrofit:$retrofit_version") {
// exclude Retrofit’s OkHttp peer-dependency module and define your own module import
exclude module: "okhttp"
}
// OkHttp and a logging interceptor
implementation("com.squareup.okhttp3:okhttp:$okhttp_version")
implementation "com.squareup.okhttp3:logging-interceptor:$okhttp_version"
project > build.gradle
buildscript {
...
ext.retrofit_version = '2.6.0'
ext.okhttp_version = '4.0.0'
...
}
package.name > external > ApiClient.kt
object ApiClient {
private const val BASE_URL = "https://test.apiary-mock.com/"
private var retrofit: Retrofit? = null
val apiClient: Retrofit
get() {
if (retrofit == null) {
val logging = HttpLoggingInterceptor()
logging.apply {
level = if (BuildConfig.DEBUG) HttpLoggingInterceptor.Level.BODY else HttpLoggingInterceptor.Level.NONE
}
val client: OkHttpClient = OkHttpClient.Builder()
.addInterceptor(logging)
.build()
retrofit = Retrofit.Builder()
.baseUrl(BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create())
.build()
}
return retrofit!!
}
}
Usage
val carRestService = ApiClient.apiClient.create(CarRestService::class.java)
Sources
exclude module
okhttp
okhttp-logging-interceptor

Retrofit2 Authorization - Global Interceptor for access token

I'm trying to use Retrofit2,
I want to add Token to my Header Like this:
Authorization: Bearer Token
but the code below doesn't work:
public interface APIService {
#Headers({"Authorization", "Bearer "+ token})
#GET("api/Profiles/GetProfile?id={id}")
Call<UserProfile> getUser(#Path("id") String id);
}
My server is asp.net webApi. Please help what should I do?

You have two choices -- you can add it as a parameter to your call --
#GET("api/Profiles/GetProfile?id={id}")
Call<UserProfile> getUser(#Path("id") String id, #Header("Authorization") String authHeader);
This can be a bit annoying because you will have to pass in the "Bearer" + token on each call. This is suitable if you don't have very many calls that require the token.
If you want to add the header to all requests, you can use an okhttp interceptor --
OkHttpClient client = new OkHttpClient.Builder().addInterceptor(new Interceptor() {
#Override
public Response intercept(Chain chain) throws IOException {
Request newRequest = chain.request().newBuilder()
.addHeader("Authorization", "Bearer " + token)
.build();
return chain.proceed(newRequest);
}
}).build();
Retrofit retrofit = new Retrofit.Builder()
.client(client)
.baseUrl(/** your url **/)
.addConverterFactory(GsonConverterFactory.create())
.build();

If you want to add Bearer Token as a Header you can do those types of process.
This is one way to work with Bearer Token
In your Interface
#Headers({ "Content-Type: application/json;charset=UTF-8"})
#GET("api/Profiles/GetProfile")
Call<UserProfile> getUser(#Query("id") String id, #Header("Authorization") String auth);
After that you will call the Retrofit object in this way
Retrofit retrofit = new Retrofit.Builder()
.baseUrl("your Base URL")
.addConverterFactory(GsonConverterFactory.create())
.build();
APIService client = retrofit.create(APIService.class);
Call<UserProfile> calltargetResponse = client.getUser("0034", "Bearer "+token);
calltargetResponse.enqueue(new Callback<UserProfile>() {
#Override
public void onResponse(Call<UserProfile> call, retrofit2.Response<UserProfile> response) {
UserProfile UserResponse = response.body();
Toast.makeText(this, " "+response.body(), Toast.LENGTH_SHORT).show();
}
#Override
public void onFailure(Call<UserProfile> call, Throwable t) {
//Toast.makeText(this, "Failed ", Toast.LENGTH_SHORT).show();
}
});
Another Way is using intercept, which is similar the previous Answer. But, that time you just need to modify interface little bit like.
#Headers({ "Content-Type: application/json;charset=UTF-8"})
#GET("api/Profiles/GetProfile")
Call<UserProfile> getUser(#Query("id") String id);
Hope this will work for you.

Based on #iagreen solution kotlin version with different classes and structure suggested by #Daniel Wilson
Make Retrofit instance like this
object RetrofitClientInstance {
private var retrofit: Retrofit? = null
private val BASE_URL = "http://yoururl"
val retrofitInstance: Retrofit?
get() {
if (retrofit == null) {
var client = OkHttpClient.Builder()
.addInterceptor(ServiceInterceptor())
//.readTimeout(45,TimeUnit.SECONDS)
//.writeTimeout(45,TimeUnit.SECONDS)
.build()
retrofit = Retrofit.Builder()
.baseUrl(BASE_URL)
.client(client)
.addConverterFactory(GsonConverterFactory.create())
.build()
}
return retrofit
}
}
Add ServiceInterceptor class like below
class ServiceInterceptor : Interceptor{
var token : String = "";
fun Token(token: String ) {
this.token = token;
}
override fun intercept(chain: Interceptor.Chain): Response {
var request = chain.request()
if(request.header("No-Authentication")==null){
//val token = getTokenFromSharedPreference();
//or use Token Function
if(!token.isNullOrEmpty())
{
val finalToken = "Bearer "+token
request = request.newBuilder()
.addHeader("Authorization",finalToken)
.build()
}
}
return chain.proceed(request)
}
}
Login Interface and data class implementation
interface Login {
#POST("Login")
#Headers("No-Authentication: true")
fun login(#Body value: LoginModel): Call<LoginResponseModel>
#POST("refreshToken")
fun refreshToken(refreshToken: String):
Call<APIResponse<LoginResponseModel>>
}
data class LoginModel(val Email:String,val Password:String)
data class LoginResponseModel (val token:String,val
refreshToken:String)
call this in any activity like this
val service = RetrofitClientInstance.retrofitInstance?.create(Login::class.java)
val refreshToken = "yourRefreshToken"
val call = service?.refreshToken(refreshToken)
call?.enqueue(object: Callback<LoginResponseModel>{
override fun onFailure(call: Call<LoginResponseModel>, t: Throwable) {
print("throw Message"+t.message)
Toast.makeText(applicationContext,"Error reading JSON",Toast.LENGTH_LONG).show()
}
override fun onResponse(call: Call<LoginResponseModel>, response: Response<LoginResponseModel>) {
val body = response?.body()
if(body!=null){
//do your work
}
}
})
for detail this video will be helpful.

This adds your token to the builder and you can change it at any time in case of login/logout.
object ApiService {
var YOUR_TOKEN = ""
private var retrofit: Retrofit = Retrofit.Builder()
.baseUrl("YOUR_URL")
.addConverterFactory(GsonConverterFactory.create())
.client(OkHttpClient.Builder().addInterceptor { chain ->
val request = chain.request().newBuilder().addHeader("Authorization", "Bearer ${YOUR_TOKEN}").build()
chain.proceed(request)
}.build())
.build()
var service: AppAPI = retrofit.create(AppAPI::class.java)
private set
}

You will need to add an Interceptor into the OkHttpClient.
Add a class called OAuthInterceptor.
class OAuthInterceptor(private val tokenType: String, private val accessToken: String) : Interceptor {
override fun intercept(chain: Interceptor.Chain): okhttp3.Response {
var request = chain.request()
request = request.newBuilder().header("Authorization", "$tokenType $accessToken").build()
return chain.proceed(request)
}
}
Following that, when you initialise your RetrofitApiService interface, you will need this.
interface RetrofitApiService {
companion object {
private const val BASE_URL = "https://api.coursera.org/api/businesses.v1/"
fun create(accessToken: String): RetrofitApiService {
val client = OkHttpClient.Builder()
.addInterceptor(OAuthInterceptor("Bearer", accessToken))
.build()
val retrofit = Retrofit.Builder()
.addConverterFactory(GsonConverterFactory.create())
.baseUrl(BASE_URL)
.client(client)
.build()
return retrofit.create(RetrofitApiService::class.java)
}
}
}
Shout out to Java Code Monk, and visit the reference link for more details.
https://www.javacodemonk.com/retrofit-oauth2-authentication-okhttp-android-3b702350

The best approach is to use the new Authenticator API.
class TokenAuthenticator : Authenticator {
override fun authenticate(route: Route?, response: Response): Request? {
if (response.request.header("Authorization") != null) {
return null
}
return response.request.newBuilder().header("Authorization", "Bearer " + token).build()
}
}
OkHttpClient.Builder().authenticator(TokenAuthenticator()).build()
Reference: https://square.github.io/okhttp/recipes/#handling-authentication-kt-java