快速打造Kotlin+MVP+Rxjava+Retrofit项目架构（引用Google推荐架构模式：契约接口）

文件目录：

主目录
mvp中的目录

主要代码示例：

• 1、一个登录模型（也叫bean、entity）

/**
 * 后台规定的接口命名的字段是大写开头
 */

class LoginModel : Base() {

    /**
     * Ext : {"Authority":3,"Token":"213bfc688a7e099b1f2a27b64f59c9e1"}
     * Message : 登录成功
     * State : true
     */

    var ext: ExtBean? = null


    class ExtBean {
        /**
         * Authority : 3
         * Token : 213bfc688a7e099b1f2a27b64f59c9e1
         */

        var authority: Int = 0
        var token: String? = null
    }
}

• 2、一个登录的契约接口

interface View : BaseContract.BaseView {
        fun loginSus(loginModel: LoginModel) //登录成功
        fun err(code: Int, message: String) //出错
    }

    interface Presenter : BaseContract.BasePresenter<View> {
        fun login(telephoneNumber: String, verificationCode: String, token: String) //登录
    }

顺便贴出BaseContract契约接口基类

/**
 * 对应mvp中的contract契约接口
 */

interface BaseContract {
    interface BasePresenter<in T> {
        /*该方法可以获取到View实例对象*/
        fun attachView(view: T)

        /*释放View对象的引用，gc才能回收View*/
        fun detachView()
    }

    interface BaseView {
        //view的一些共有方法
        fun showError(e: Throwable)
        fun complete()
    }
}

• 3、一个实现了View接口充当V层的Activity

/**
 * 模拟登录的view层
 */
class MainActivity : BaseActivity<LoginContract.View,LoginContract.Presenter>(),LoginContract.View {
    override fun err(code: Int, message: String) {
        ToastUtils.showShort("错误码：$code\n错误信息：$message")
    }

    override fun loginSus(loginModel: LoginModel) {
        disMissLoading()
        if (loginModel.State) {
            ToastUtils.showShort("登录成功")
        }else{
            ToastUtils.showShort(loginModel.Message)
        }
    }

    override fun showError(e: Throwable) {
        disMissLoading()
    }

    override fun complete() {

    }

    override fun getLayoutId(): Int = R.layout.activity_main

    override fun configView() {
        login.setOnClickListener({
            showLoading()
            mPresenter!!.login("18381309101","1111","") })
    }

    override fun initData() {

    }

    override fun initPresenter(): LoginContract.Presenter = LoginPresenter()

}

• 实现Presenter，充当P层的一个登录的Presenter

class LoginPresenter : RxPresenter<LoginContract.View>(), LoginContract.Presenter {

    /**
     * 登录
     * @param telephoneNumber
     * @param verificationCode
     * @param token
     */
    override fun login(telephoneNumber: String, verificationCode: String, token: String) {
        val subscription = HttpManager.getWorkHttpService()!!.signIn(telephoneNumber, verificationCode, token)
                .compose(ScheduleTransformer.instance)
                .subscribe(object : ObserverImp<Any>() {

                    override fun onErr(errCode: Int, str: String) {
                        mView!!.err(errCode,str)
                    }

                    override fun doNext(loginModel: Any) {
                        mView!!.loginSus(loginModel as LoginModel)
                    }
                })
        addSubscribe(subscription)
    }
}

到这里mvp构建就已经完成了，但是那些日常操作：统一错误处理、文件进度监听、Retorfit的自定义拦截器、内存泄漏处理、Retrofit自定义转换器等等还需要完成。。。

一些重要的代码：

• 统一错误处理

override fun onError(e: Throwable) {
        var e = e
        var throwable = e
        //获取最根源的异常
        while (throwable.cause != null) {
            if (e is HttpException) {
                break
            }
            e = throwable
            throwable = throwable.cause!!
        }
        if (e is HttpException) {
            when (e.code()) {
                UNAUTHORIZED -> onErr(UNAUTHORIZED, "")
                FORBIDDEN -> onErr(FORBIDDEN, "权限错误")          //权限错误，需要实现
                NOT_FOUND -> onErr(NOT_FOUND, "")
                REQUEST_TIMEOUT -> onErr(REQUEST_TIMEOUT, "")
                GATEWAY_TIMEOUT -> onErr(GATEWAY_TIMEOUT, "")
                INTERNAL_SERVER_ERROR -> onErr(INTERNAL_SERVER_ERROR, "")
                BAD_GATEWAY -> onErr(BAD_GATEWAY, "")
                SERVICE_UNAVAILABLE -> onErr(SERVICE_UNAVAILABLE, "")
                else -> onErr(ERR_CODE_NET, "")
            }
        } else if (e is SocketTimeoutException) {
            onErr(GATEWAY_TIMEOUT, "请求超时!")
        } else if (e is UnknownHostException) {
            onErr(ERR_CODE_NET, "网络连接失败!")
        } else {
            onErr(ERR_CODE_UNKNOWN, "未知错误!")
        }
    }

• 2、文件进度监听

 override fun read(sink: Buffer, byteCount: Long): Long {
                try {
                    val bytesRead = super.read(sink, byteCount)
                    if (totalBytesRead == 0L && listener != null) {
                        listener.DLoadStart()
                    }
                    totalBytesRead += if (bytesRead != -1L) bytesRead else 0

                    if (null != listener) {
                        if (bytesRead == -1L) {
                            listener.DLoadSuccess()
                        }
                        if ((totalBytesRead * 100L / responseBody.contentLength()).toInt() > lastPro) {
                            listener.DLoadProgress((totalBytesRead * 100L / responseBody.contentLength()).toInt())
                        }
                        lastPro = (totalBytesRead * 100L / responseBody.contentLength()).toInt()
                    }
                    return bytesRead
                } catch (e: IOException) {
                    listener?.DLoadFail()
                }

                return 0L

            }

• 3、自定义文件下载拦截器

/**
 * 文件下载拦截器
 */

class DownLoadInterceptor(private val listener: DLProListener) : Interceptor {

    @Throws(IOException::class)
    override fun intercept(chain: Interceptor.Chain): Response {
        val originalResponse = chain.proceed(chain.request())

        return originalResponse.newBuilder()
                .body(FileResBody(originalResponse.body(), listener))
                .build()
    }
}

• 4、内存泄漏处理，释放对activity 的引用

 override fun attachView(view: T) {
        this.mView = view
    }

    override fun detachView() {
        this.mView = null
        unSubscribe()
    }

• 5、自定义单例的Retrofit转换器

/**
 * 单例实现的转换器，统一指定每一个接口请求实在io线程，回调在ui线程
 */

class ScheduleTransformer<T>
/**
 * 私有的构造函数
 */
private constructor() : Observable.Transformer<T, T> {
    /**
     *懒加载内部单例
     */
    private object TransformerHolder {
        private val instance: ScheduleTransformer<Any>? = null
        fun getInstance(): ScheduleTransformer<Any> {
            return instance ?: ScheduleTransformer<Any>()
        }
    }

    override fun call(tObservable: Observable<T>): Observable<T> {
        return tObservable.subscribeOn(Schedulers.io())
                .unsubscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
    }

    /**
     * 伴生
     */
    companion object {
        val instance: ScheduleTransformer<Any>
            get() = TransformerHolder.getInstance()
    }
}

该架构用起来十分方便和灵活，里面还有常用的一些基类和处理类，已经在正式项目中使用，请大胆尝试，Github地址：实战MVP架构，包含JAVA版本，欢迎打星鼓励！