本文介紹了Kotlin + Retrofit + RxJava簡單封裝使用詳解，分享給大家，具體如下：
實例化Retrofit
object RetrofitUtil { val CONNECT_TIME_OUT = 30//連接超時時長x秒val READ_TIME_OUT = 30//讀數據超時時長x秒val WRITE_TIME_OUT = 30//寫數據接超時時長x秒val retrofit: Retrofit by lazy { Log.d("RetrofitUtil", "retrofit init lazy") Retrofit.Builder() .baseUrl("http://gank.io/api/") //本文以GitHub API為例.addConverterFactory(GsonConverterFactory.create()) .addCallAdapterFactory(RxJava2CallAdapterFactory.create()) .client(getOkHttpClient()) .build() } private fun getOkHttpClient(): OkHttpClient { val builder = OkHttpClient.Builder() builder.connectTimeout(CONNECT_TIME_OUT.toLong(), TimeUnit.SECONDS) .writeTimeout(WRITE_TIME_OUT.toLong(), TimeUnit.SECONDS) .readTimeout(READ_TIME_OUT.toLong(), TimeUnit.SECONDS) if (BuildConfig.DEBUG) { builder.addInterceptor(HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.BODY)) } else { builder.addInterceptor(HttpLoggingInterceptor().setLevel(HttpLoggingInterceptor.Level.NONE)) } // 設置請求頭builder.addInterceptor { chain -> val time = (System.currentTimeMillis() / 1000).toString() + "" val requestBuilder = chain.request().newBuilder() requestBuilder.addHeader("time", time) chain.proceed(requestBuilder.build()) } return builder.build() }}返回數據封裝
class Response<T> { var error: Boolean = false var results: T? = null}demo中用了gank.io的開發api，之前一般項目的返回格式是code + message + T的格式。
api接口錯誤/異常統一處理類
class ApiException : Exception { var code: Int = 0//錯誤碼var msg: String? = null//錯誤信息constructor(throwable: Throwable, code: Int) : super(throwable) { this.code = code } constructor(code: Int, msg: String) { this.code = code this.msg = msg }}定義ExceptionFunction處理onErrorResumeNext：
class ExceptionFunction<T> : Function<Throwable, Observable<T>> { override fun apply(@NonNull throwable: Throwable): Observable<T> { Log.e("ExceptionFunction", throwable.message) return Observable.error(ExceptionEngine().handleException(throwable)) }}/** * 錯誤/異常處理工具*/class ExceptionEngine { val UN_KNOWN_ERROR = 1000//未知錯誤val ANALYTIC_SERVER_DATA_ERROR = 1001//解析(服務器)數據錯誤val CONNECT_ERROR = 1002//網絡連接錯誤val TIME_OUT_ERROR = 1003//網絡連接超時fun handleException(e: Throwable): ApiException { val ex: ApiException if (e is ApiException) { //服務器返回的錯誤return e } else if (e is HttpException) { //HTTP錯誤ex = ApiException(e, e.code()) ex.msg = "網絡錯誤:" + ex.code return ex } else if (e is JsonParseException || e is JSONException || e is ParseException || e is MalformedJsonException) { //解析數據錯誤ex = ApiException(e, ANALYTIC_SERVER_DATA_ERROR) ex.msg = "解析錯誤" return ex } else if (e is ConnectException) {//連接網絡錯誤ex = ApiException(e, CONNECT_ERROR) ex.msg = "連接失敗" return ex } else if (e is SocketTimeoutException) {//網絡超時ex = ApiException(e, TIME_OUT_ERROR) ex.msg = "網絡超時" return ex } else { //未知錯誤ex = ApiException(e, UN_KNOWN_ERROR) ex.msg = e.message return ex } }}封裝請求處理
object Rx { /** * Rxlifecycle綁定生命週期*/ fun <T, E> get(observable: Observable<Response<T>>, lifecycleProvider: LifecycleProvider<E>): Observable<T> { // 請求綁定生命週期，防止內存洩漏，同時返回回調之後頁面已銷毀造成的空指針錯誤if (lifecycleProvider is RxAppCompatActivity) { val rxAppCompatActivity = lifecycleProvider as RxAppCompatActivity observable.compose(rxAppCompatActivity.bindUntilEvent(ActivityEvent.DESTROY)) } else if (lifecycleProvider is RxFragment) { val rxFragment = lifecycleProvider as RxFragment observable.compose(rxFragment.bindUntilEvent(FragmentEvent.DESTROY)) } return observable .compose(HandleResult()) .onErrorResumeNext(ExceptionFunction()) } /** * 部分後台請求*/ fun <T> get(observable: Observable<Response<T>>): Observable<T> { return observable .compose(HandleResult()) .onErrorResumeNext(ExceptionFunction()) } private class HandleResult<T> : ObservableTransformer<Response<T>, T> { override fun apply(upstream: Observable<Response<T>>): ObservableSource<T> { return upstream.flatMap { response -> createResult(response) } .subscribeOn(Schedulers.io()) .unsubscribeOn(Schedulers.io()) .observeOn(AndroidSchedulers.mainThread()) } } private fun <T> createResult(response: Response<T>): Observable<T> { return Observable.create({ subscriber -> if (response.error) throw ApiException(-1, "服務器異常") // 一般來說，自己的服務器異常會返回相應的code和message else response.results?.let { subscriber.onNext(response.results!!) } ?: subscriber.onComplete() }) }}定義HttpObserver統一處理返回
abstract class HttpObserver<T> : Observer<T> { /** * 標記是否為特殊情況*/ private var resultNull: Boolean = true override fun onComplete() { // 特殊情況：當請求成功，但T == null時會跳過onNext，仍需當成功處理if (resultNull) onSuccess(null) } override fun onSubscribe(d: Disposable) { // 可在此處加上dialog } override fun onError(e: Throwable) { if (e is ApiException) { onError(e.code, e.msg) } else { onError(0, e.message) } } override fun onNext(t: T) { resultNull = false onSuccess(t) } abstract fun onSuccess(t: T?) /** * 統一處理失敗，比如登錄失效等* * @param code * @param msg */ open fun onError(code: Int, msg: String?) { }} Api
class Result { var _id: String? = null var createdAt: String? = null var desc: String? = null var publishedAt: String? = null var source: String? = null var type: String? = null var url: String = "" var isUsed: Boolean = false var who: String? = null var images: List<String>? = null /** * 妹子小圖*/ fun meiziSmallUrl(): String { val meizi = url return meizi.replace("large", "small") }}interface Apiservice { @GET("data/{type}/10/{page}") fun getGank(@Path("type") type: String, @Path("page") page: Int): Observable<Response<List<Result>>>}object Api { val apiservice: Apiservice by lazy { Log.d("Api", "apiservice create lazy") RetrofitUtil.retrofit.create(Apiservice::class.java) }}使用
override fun loadData() { Rx.get(Api.apiservice.getGank(getType(), mIntPage), this).subscribe(object : HttpObserver<List<Result>>() { override fun onSuccess(t: List<Result>?) { //getDataSuccess(t) } override fun onError(code: Int, msg: String?) { super.onError(code, msg) //getDataFailed() } }) }使用了Rxlifecycle綁定生命週期來處理可能發生的內存洩漏問題，Fragment跟Activity需要繼承Rx相應的基類。
練手項目
Meizikt Gank.io Android客戶端，使用Kotlin + Retrofit2 + RxJava
以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。