如何在 RxJava 2 自定义运算符的 onSubscribe 上获取 RetroFit 请求的 URL 和方法？

Question

因此，我尝试集成 Http 请求的 Firebase 性能并手动添加它们，如此处所示（步骤 9）。

我正在使用 Retrofit 2 和 RxJava 2，所以我想到了做一个自定义运算符，检查下面的代码：

改造 2 客户端

@GET("branch-{environment}/v2/branches")
    fun getBranch(@Path("environment") environment: String, @Query("location") location: String, @Query("fulfilment_type") fulfilmentType: String): Single<Response<GetBranchResponse>>

RxJava 调用 Retrofit 客户端

private val client: BranchClient = clientFactory.create(urlProvider.apiUrl)

override fun getBranch(postCode: String, fulfilmentType: FulfilmentType): Single<GetBranchResponse> {
        return client
                .getBranch(environment, postCode.toUpperCase(), fulfilmentType.toString())
                .lift(RxHttpPerformanceSingleOperator(URL?, METHOD?))
                .map { it.body() }
                .subscribeIO() //custom Kotlin extension 
                .observeMain() //custom Kotlin extension 
                ...
    } 

RxJava 2 自定义操作符通过 lift：

class RxHttpPerformanceSingleOperator<T>(private val url: String, private val method: String) : SingleOperator<Response<T>, Response<T>> {


    private lateinit var metric: HttpMetric

    @Throws(Exception::class)
    override fun apply(observer: SingleObserver<in Response<T>>): SingleObserver<in Response<T>> {
        return object : SingleObserver<Response<T>> {

            override fun onSubscribe(d: Disposable) {

                    metric = FirebasePerformance.getInstance().newHttpMetric(url,
                            method.toUpperCase())
                    metric.start()


                observer.onSubscribe(d)
            }

            override fun onSuccess(t: Response<T>) {
                observer.onSuccess(t)

                //More info: https://firebase.google.com/docs/perf-mon/get-started-android
                metric.setRequestPayloadSize(t.raw().body().contentLength())
                metric.setHttpResponseCode(t.code())
                metric.stop()
            }

            override fun onError(e: Throwable) {
                observer.onError(e)
                metric.stop()
            }


        }
    }

所以目前我不确定如何以正确的方式获取请求的 URL 和方法（标记为 URL？和 METHOD？）发送给操作员，

我需要他们在 onSubscribe 上启动指标..但我没有得到回应...

---

目前 UGLYYYYYYYY 我的做法是：

添加到改造客户端：

@GET("branch-{environment}/v2/branches")
    fun getBranchURL(@Path("environment") environment: String, @Query("location") location: String, @Query("fulfilment_type") fulfilmentType: String): Call<JsonObject>

添加参数如下：

val request = client.getBranchURL(environment, postCode.toUpperCase(), fulfilmentType.toString()).request()

url = request.url().toString()
method = request.method()

这使得我在客户端上每个请求都有 2 个条目......这没有意义。

---

一路上有一些有用的线索： -如何使用 rxjava 在 Retrofit 2.0 中获取请求 url？

Answer 1

添加一个 RetrofitInterceptor到你的HttpClient.Builder并在那里FirebaseInstance生成你的HttpMetrics：

class FirebasePerformanceInterceptor(val performanceInstance: FirebasePerformance) : Interceptor {
    override fun intercept(chain: Interceptor.Chain): Response {
        val request = chain.request()
        //Get request values
        val url = request.url().url()
        val requestPayloadSize = request.body()?.contentLength() ?: 0L
        val httpMethod = request.method()

        //Initialize http trace
        val trace = performanceInstance.newHttpMetric(url, httpMethod)
        trace.setRequestPayloadSize(requestPayloadSize)
        trace.start()

        //Proceed
        val response = chain.proceed(chain.request())

        //Get response values
        val responseCode = response.code()
        val responsePayloadSize = response.body()?.contentLength() ?: 0L

        //Add response values to trace and close it
        trace.setHttpResponseCode(responseCode)
        trace.setResponsePayloadSize(responsePayloadSize)
        trace.stop()

        return response
    }
}

您可以直接复制并粘贴此代码即可运行。享受！