MVP for Kotlin

一、工具

• 网络层retrofit+rxjava
• 使用mvp
• 使用databing进行组件注入

二、结构
1、网络层
实例化 Retrofit 使用 companion object ，因为kotlin没有静态类，使用这种方式创造一个单例

class ApiClient {
   /.../

    companion object {
        fun retrofit() : Retrofit {
            return ApiClient().retrofit()
        }
    }

    fun retrofit() : Retrofit {
        val builder = OkHttpClient.Builder() builder.connectTimeout(S_DEFAULT_TIMEOUT, TimeUnit.SECONDS).writeTimeout(S_DEFAULT_TIMEOUT, TimeUnit.SECONDS).readTimeout(S_DEFAULT_TIMEOUT, TimeUnit.SECONDS)

        if (BuildConfig.DEBUG) {
            // Log信息拦截器
            val loggingInterceptor = HttpLoggingInterceptor() loggingInterceptor.level = HttpLoggingInterceptor.Level.BODY
            //设置 Debug Log 模式
            builder.addInterceptor(loggingInterceptor)
        }

        val okHttpClient = builder.build()

        return Retrofit.Builder().baseUrl(getHost()).addConverterFactory(GsonConverterFactory.create()).addCallAdapterFactory(RxJava2CallAdapterFactory.create()).client(okHttpClient).build()
    }

    /**
     * 根据当前配置设置host地址
     *
     * @return host 地址
     */
    fun getHost() : String {
        if (FORCEUSE_TEST_HOST) {
            return HS_HOST_TEST
        } else {
            if (BuildConfig.DEBUG) {
                return HS_HOST_TEST
            } else {
                return HS_HOST
            }
        }
    }
}

统一一个网络请求返回数据的接口，这里遇到了问题，但我使用一个kt文件的activity时，这里对model.data进行判空（== 、 !!） ，无论怎么样，model.data 都被判断成空的，但用一个普通的activity却可以

abstract class ApiCallback < T > {

    abstract fun onFailure(errorCode: Int) abstract fun onSuccess(model: T)

    fun onFinish() {}

    fun onNext(model: HttpBase < T > ?) {
        if (model == null) {
            onFailure(Error.S_ERROR_DATA) return
        }
        if (model.errorCode == 0) {
            try {
                onSuccess(model.data as T)
            } catch(e: Exception) {
                onFailure(Error.S_ERROR_DATA)
            }
        } else {
            onFailure(Error.S_ERROR_DATA)
        }
    }

    fun onError(e: Throwable) {
        e.printStackTrace() if (e is HttpException) {
            val code = e.code() LogUtils.i("network -> onError: " + code) onFailure(code)
        } else {
            onFailure(Error.S_UNKNOW_ERROR)
        }
    }

    fun onComplete() {
        onFinish()
    }
}

这个接口的返回值是HttpBase<User>，在HttpBase中做了请求错误码统一的判断，方便处理

@FormUrlEncoded
@POST("user/login.json")
fun login(@FieldMap params: Map<String, String>): Flowable<HttpBase<User>>

这里抛出一个异常就要写注解了 @Throws(Exception::class)

class HttpBase <T> {
    var errorCode: Int = 0
    var data: T ? =null
}

2、Presenter

open class BasePresenter<V>(var mvpView: V) {
    private val TAG = BasePresenter::class.java.simpleName

    var apiStores = ApiClient.retrofit().create(ApiStores::class.java)
    var mCompositeDisposable: CompositeDisposable = CompositeDisposable()

    fun detachView() {
        onUnsubscribe()
    }

    fun <T> addSubscription(flowable: Flowable<HttpBase<T>>, apiCallback: ApiCallback<T>) {
        mCompositeDisposable.add(flowable
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(object : Consumer<HttpBase<T>> {
                    @Throws(Exception::class)
                    override fun accept(t: HttpBase<T>?) {
                        apiCallback.onNext(t)
                    }
                }, object : Consumer<Throwable> {
                    @Throws(Exception::class)
                    override fun accept(t: Throwable) {
                        LogUtils.d(t)
                        apiCallback.onError(t)
                    }

                }, object : Action {
                    @Throws(Exception::class)
                    override fun run() {
                        apiCallback.onComplete()
                    }
                }))
    }

    fun addSubscription(disposable: Disposable) {
        mCompositeDisposable.add(disposable)
    }

    fun onUnsubscribe() {
        mCompositeDisposable.clear()
    }
}

3、Fragment/Activity

open class BaseFragment : Fragment() {
    private val TAG = BaseFragment::class.java.simpleName

    protected var apiStores = ApiClient.retrofit().create(ApiStores::class.java)
    private var mCompositeDisposable: CompositeDisposable = CompositeDisposable()

    override fun onDestroy() {
        onUnsubscribe()
        super.onDestroy()
    }

    fun <T> addSubscription(flowable: Flowable<HttpBase<T>>, apiCallback: ApiCallback<T>) {
        mCompositeDisposable.add(flowable
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(object : Consumer<HttpBase<T>> {
                    @Throws(Exception::class)
                    override fun accept(t: HttpBase<T>?) {
                        apiCallback.onNext(t)
                    }
                }, object : Consumer<Throwable> {
                    @Throws(Exception::class)
                    override fun accept(t: Throwable) {
                        apiCallback.onError(t)
                    }
                }, object : Action {
                    @Throws(Exception::class)
                    override fun run() {
                        apiCallback.onComplete()
                    }
                }))
    }

    fun addSubscription(disposable: Disposable) {
        mCompositeDisposable.add(disposable)
    }

    fun onUnsubscribe() {
        mCompositeDisposable.clear()
    }
}

open class BaseActivity : Activity() {
    private val TAG = BaseActivity::class.java.simpleName

    protected var apiStores = ApiClient.retrofit().create(ApiStores::class.java)
    private var mCompositeDisposable: CompositeDisposable = CompositeDisposable()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onDestroy() {
        onUnsubscribe()
        super.onDestroy()
    }

    fun <T> addSubscription(flowable: Flowable<HttpBase<T>>, apiCallback: ApiCallback<T>) {
        mCompositeDisposable.add(flowable
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(object : Consumer<HttpBase<T>> {
                    @Throws(Exception::class)
                    override fun accept(t: HttpBase<T>?) {
                        apiCallback.onNext(t)
                    }
                }, object : Consumer<Throwable> {
                    @Throws(Exception::class)
                    override fun accept(t: Throwable) {
                        apiCallback.onError(t)
                    }

                }, object : Action {
                    @Throws(Exception::class)
                    override fun run() {
                        apiCallback.onComplete()
                    }
                }))
    }

    fun addSubscription(disposable: Disposable) {
        mCompositeDisposable.add(disposable)
    }

    fun onUnsubscribe() {
        mCompositeDisposable.clear()
    }
}

三、问题
在kt的activcity中，导入databinding时显示异常， 查了一些资料，但是没什么结果，好在kt提供自己的view注入。但是在普通的activity中却无法使用

class MainActivity : MvpActivity<MainPresenter>(), MainView {

    override fun createPresenter(): MainPresenter {
        return MainPresenter(this)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        mvpPresenter.getName()
    }

    override fun setTextView(name: String) {
        LogUtils.d("name : " + name)
        text.setText(name)
    }

    override fun error(error: Int) {
        LogUtils.d(error)
    }
}