如何在 Android GraphQL 中重新生成令牌？

Question

What is the better approach to regenerate the JWT token using refresh token in Apollo Graphql in Andriod Kotlin?.

Now we are using an Auth interceptor that extends ApolloInterceptor to attach the JWT token in the request header.

I want to check whether the Toke expires from here and it should call another mutation to generate a new token. Then it should proceed with the previous call with the new token.

Please refer to the code below

  class AuthInterceptor(private val jwtToken: String) : ApolloInterceptor {
        override fun interceptAsync(
            request: ApolloInterceptor.InterceptorRequest,
            chain: ApolloInterceptorChain,
            dispatcher: Executor,
            callBack: ApolloInterceptor.CallBack
        ) {
            val header = request.requestHeaders.toBuilder().addHeader(
                HEADER_AUTHORIZATION,
                "$HEADER_AUTHORIZATION_BEARER $jwtToken"
            ).build()
            chain.proceedAsync(request.toBuilder().requestHeaders(header).build(), dispatcher, callBack)
        }
    
        override fun dispose() {}
    
        companion object {
            private const val HEADER_AUTHORIZATION = "Authorization"
            private const val HEADER_AUTHORIZATION_BEARER = "Bearer"
        }
    }

Answer 1

If you are using Apollo Android Client V3 and Using Kotlin Coroutine then use Apollo Runtime Dependency and Try HttpInterceptor instead of ApolloInterceptor . I think this is the better/best approach. For Reference Click Here

In your app-level build.gradle file

plugins {
......
    id("com.apollographql.apollo3").version("3.5.0")
.....
}

dependencies {
  implementation("com.apollographql.apollo3:apollo-runtime")
}

Now write your interceptor for the Apollo client.

FYI: If you've added the Authorization header using Interceptor or using addHttpHeader in client already then remove it or don't add header here val response = chain.proceed(request.newBuilder().addHeader("Authorization", "Bearer $token").build()) , just build the request. Otherwise Authorization header will add multiple times in the request. So, be careful.

class AuthorizationInterceptor @Inject constructor(
    val tokenRepo: YourTokenRepo
) : HttpInterceptor {
      private val mutex = Mutex()
    
      override suspend fun intercept(request: HttpRequest, chain: HttpInterceptorChain): HttpResponse {
        var token = mutex.withLock {
          // get current token
        }
    
        val response = chain.proceed(request.newBuilder().addHeader("Authorization", "Bearer $token").build())
    
        return if (response.statusCode == 401) {
          token = mutex.withLock {
            // get new token from your refresh token API
          }
          chain.proceed(request.newBuilder().addHeader("Authorization", "Bearer $token").build())
        } else {
          response
        }
      }
    }

Configure your Apollo client like below.

ApolloClient.Builder()
            .httpServerUrl(BASE_GRAPHQL_URL)
            .webSocketServerUrl(BASE_GRAPHQL_WEBSOCKET_ENDPOINT) // if needed
            .addHttpHeader("Accept", "application/json")
            .addHttpHeader("Content-Type", "application/json")
            .addHttpHeader("User-Agent", userAgent)
            .addHttpInterceptor(AuthorizationInterceptor(YourTokenRepo))
            .httpExposeErrorBody(true)
            .build()