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简易MVVM网络请求框架（基于Kotlin实现）

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使用kotlin以最少代码实现retrofit+okhttp的网络请求

简易MVVM网络请求框架（基于Kotlin实现）

使用kotlin以最少代码实现retrofit+okhttp的网络请求

retrofit+okhttp的初始化

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object ApiClient {
    private val okHttpClient: OkHttpClient
    private val retrofit: Retrofit

    init {
        val logger = HttpLoggingInterceptor()
        if (BuildConfig.DEBUG) {
            logger.level = HttpLoggingInterceptor.Level.BODY
        } else {
            logger.level = HttpLoggingInterceptor.Level.NONE
        }
        val cache = Cache(NicebuyApp.app.cacheDir, 10 * 1024 * 1024)
        okHttpClient = OkHttpClient.Builder().run {
            readTimeout(30, TimeUnit.SECONDS)
            writeTimeout(60, TimeUnit.SECONDS)
            addInterceptor(logger)
            cache(cache)
            build()
        }
        val gson = GsonBuilder()
                .setLenient()
                .create()
        retrofit = Retrofit.Builder().run {
            baseUrl("https://www.nicebuy.io")
            addConverterFactory(GsonConverterFactory.create(gson))
            client(okHttpClient)
            build()
        }
    }
    
    fun getRetrofit(): Retrofit {
        return retrofit
    }

    fun getOkHttpClient(): OkHttpClient {
        return okHttpClient
    }
}

接口service定义

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interface TestService {
    @GET("/v1/user/info")
    suspend fun getUserInfo(@Query("uid") uid: String): ApiResponse<UserInfo>
}

定义一个顶层函数callFromNet

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suspend fun <T> callFromNet(apiFunc: suspend () -> ApiResponse<T>): Resource<T> {
    return try {
        val result = apiFunc.invoke()
        if (result.code == 0) {
            Resource.success(result.data, result.code, result.status)
        } else {
            Resource.error(null, result.code, result.status)
        }
    } catch (error: HttpException) {
        if (BuildConfig.DEBUG) error.printStackTrace()
        handleError(error)
    } catch (throwable: Throwable) {
        if (BuildConfig.DEBUG) throwable.printStackTrace()
        Resource.error(null, 0, throwable.message ?: throwable.toString())
    }
}

private fun <T> handleError(error: HttpException): Resource<T> {
    return Resource.error(null, error.code(), error.message())
}

Repo的实现

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class TestRepo(val context: CoroutineContext) {
    private val service: TestService = ApiClient.getRetrofit().create()

    fun getUserInfo(uid: String): LiveData<Resource<UserInfo>> {
        return liveData(context) {
            emit(Resource.loading(null))
            //emitSource(loadFromDb())    //你可以从数据库加载
            val resource = callFromNet {
                service.getUserInfo()
            }
            emit(resource)
        }
    }
}

ViewModel实现

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class TestViewModel : ViewModel() {
    private val testRepo =  TestRepo(viewModelScope.coroutineContext)
    private val _uidData = MutableLiveData<String>()
    val userInfoData = _uidData.switchMap {
        testRepo.getUserInfo(it)
    }

    fun setUserId(uid: String) {
        _uidData.value = uid
    }
}

那么activity里面的使用就很简单了

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private val testViewModel : TestViewModel by viewModels()

private fun getUserInfo(uid: String) {
    testViewModel.userInfoData.observe(this, Observer {
        when (it.status) {
            Status.SUCCESS -> TODO()
            Status.ERROR -> TODO()
            Status.LOADING -> TODO()
        }
    })
    testViewModel.setUserId(uid)
}