Question

我必须在后台线程中执行http请求（Retrofit 2）。

方法1：

 suspend fun getTraidersList(): TransportResponse = withContext(Dispatchers.IO) {
            val traderMonitorRestClient = RestClientFactory.createRestClient(TraderMonitorRestClient::class.java)
            executeOperation { traderMonitorRestClient.getTraidersList() }
        }


  suspend private fun executeOperation(transportOperation: suspend () -> Response<*>): TransportResponse {
            try {
                val response: Response<*> = transportOperation()
                return onResponse(response)
            } catch (e: Throwable) {
                return onNetworkFailure(e)
            }
        }
}

如您所见，方法getTraidersList()是由withContext(Dispatchers.IO)在后台线程中启动的。但是在方法executeOperation中，我没有使用withContext(Dispatchers.IO)。

好。很好。

方法2：

在方法withContext(Dispatchers.IO)中也使用executeOperation

suspend fun getTraidersList(): TransportResponse = withContext(Dispatchers.IO) {
            val traderMonitorRestClient = RestClientFactory.createRestClient(TraderMonitorRestClient::class.java)
            executeOperation { traderMonitorRestClient.getTraidersList() }
}

 suspend private fun executeOperation(transportOperation: suspend () -> Response<*>): TransportResponse = withContext(Dispatchers.IO) {
            try {
                val response: Response<*> = transportOperation()
                onResponse(response)
            } catch (e: Throwable) {
                onNetworkFailure(e)
            }
}

两种方法都能奏效。但是哪种方法是正确的？也许这两种方法都是正确的？

Answer 1

如果要在其他任何地方重用executeOperation方法，则可以将其放入另一个线程中，但是就您而言，暂时不需要。

如果您想重用executeOperation方法，这也可以工作。

suspend fun getTraidersList(): TransportResponse {
            val traderMonitorRestClient = RestClientFactory.createRestClient(TraderMonitorRestClient::class.java)
            executeOperation { traderMonitorRestClient.getTraidersList() }
}

 suspend private fun executeOperation(transportOperation: suspend () -> Response<*>): TransportResponse = withContext(Dispatchers.IO) {
            try {
                val response: Response<*> = transportOperation()
                onResponse(response)
            } catch (e: Throwable) {
                onNetworkFailure(e)
            }
}

一次使用withContext两次。两者都起作用，或者

1 个答案: