Kotlin + Retrofit + RxJava简单封装使用详解

object RetrofitUtil {  val CONNECT_TIME_OUT = 30//连接超时时长x秒  val READ_TIME_OUT = 30//读数据超时时长x秒  val WRITE_TIME_OUT = 30//写数据接超时时长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为例        .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))    }    // 设置请求头    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()  }}

class Response<T> {  var error: Boolean = false  var results: T? = null}

class ApiException : Exception {  var code: Int = 0//错误码  var msg: String? = null//错误信息  constructor(throwable: Throwable, code: Int) : super(throwable) {    this.code = code  }  constructor(code: Int, msg: String) {    this.code = code    this.msg = msg  }}

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))  }}/** * 错误/异常处理工具 */class ExceptionEngine {  val UN_KNOWN_ERROR = 1000//未知错误  val ANALYTIC_SERVER_DATA_ERROR = 1001//解析(服务器)数据错误  val CONNECT_ERROR = 1002//网络连接错误  val TIME_OUT_ERROR = 1003//网络连接超时  fun handleException(e: Throwable): ApiException {    val ex: ApiException    if (e is ApiException) {  //服务器返回的错误      return e    } else if (e is HttpException) {       //HTTP错误      ex = ApiException(e, e.code())      ex.msg = "网络错误:" + ex.code      return ex    } else if (e is JsonParseException        || e is JSONException        || e is ParseException || e is MalformedJsonException) { //解析数据错误      ex = ApiException(e, ANALYTIC_SERVER_DATA_ERROR)      ex.msg = "解析错误"      return ex    } else if (e is ConnectException) {//连接网络错误      ex = ApiException(e, CONNECT_ERROR)      ex.msg = "连接失败"      return ex    } else if (e is SocketTimeoutException) {//网络超时      ex = ApiException(e, TIME_OUT_ERROR)      ex.msg = "网络超时"      return ex    } else { //未知错误      ex = ApiException(e, UN_KNOWN_ERROR)      ex.msg = e.message      return ex    }  }}

object Rx {  /**   * Rxlifecycle绑定生命周期   */  fun <T, E> get(observable: Observable<Response<T>>, lifecycleProvider: LifecycleProvider<E>): Observable<T> {    // 请求绑定生命周期，防止内存泄漏，同时返回回调之后页面已销毁造成的空指针错误    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())  }  /**   * 部分后台请求   */  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, "服务器异常") // 一般来说，自己的服务器异常会返回相应的code和message      else        response.results?.let {          subscriber.onNext(response.results!!)        } ?: subscriber.onComplete()    })  }}

abstract class HttpObserver<T> : Observer<T> {  /**   * 标记是否为特殊情况   */  private var resultNull: Boolean = true  override fun onComplete() {    // 特殊情况：当请求成功，但T == null时会跳过onNext，仍需当成功处理    if (resultNull)      onSuccess(null)  }  override fun onSubscribe(d: Disposable) {    // 可在此处加上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?)  /**   * 统一处理失败，比如登录失效等   *   * @param code   * @param msg   */  open fun onError(code: Int, msg: String?) {  }}

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  /**   * 妹子小图   */  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)  }}

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()      }    })  }