Question

我们已经编写了一个Kotlin库来处理一些网络逻辑。该库本身包含使用AsyncTask中的HttpURLConnection工具的java.net.*。

private inner class ClickstreamTask(
                                    headers: HashMap<String, String>,
                                    params: Request,
                                    success: (() -> Unit)? = null,
                                    failure: ((statusCode: Int?, json: 
HashMap<String, String>?) -> Unit)? = null) : AsyncTask<Void, Unit, Unit>() {

    private var headers: HashMap<String, String> = headers
    private var paramaters: Request = params
    private var success: (() -> Unit)? = success
    private var failure: ((statusCode: Int?, json: HashMap<String, String>?) -> Unit)? = failure

    override fun doInBackground(vararg params: Void){

        val url = try {
            URL(getURLString() + path)
        } catch (e: Exception) {
            failure?.invoke(null, hashMapOf("error" to "Invalid URL."))
            return Unit
        }

        var request = try{
            url.openConnection() as HttpURLConnection
        } catch (e: Exception){
            failure?.invoke(null, hashMapOf("error" to "Unable to establish connection"))
            return Unit
        }

        request.doInput = false
        request.doOutput = true
        val mapper = jacksonObjectMapper()

        request.requestMethod = "POST"
        val httpBody = try {
            mapper.writeValueAsBytes(paramaters)
        } catch (e: Exception) {
            failure?.invoke(null, hashMapOf("error" to "Invalid params."))
            return Unit
        }

        for ((key, value) in headers) {
            request.setRequestProperty(key, value)
        }

        try{
            request.outputStream.write(httpBody)
        }catch (e: Throwable){
            request.outputStream.close()
            failure?.invoke(null, hashMapOf("error" to "Issue writing to URL"))
            return Unit
        }
        request.outputStream.close()


        if (request.responseCode != 200){
            failure?.invoke(request.responseCode, hashMapOf("Failed request" to request.responseMessage))
            return Unit
        }

        success?.invoke()
        return Unit
    }
}

当我们使用在飞行模式下运行库的Android应用程序时，应用程序因未捕获的异常而崩溃＆＃34; UnknownHostException＆＃34;：

引起：java.net.UnknownHostException：无法解析主机＆＃34; ste03lbclkapp00.iteclientsys.local＆＃34;：没有与之关联的地址主机名在 java.net.Inet6AddressImpl.lookupHostByName（Inet6AddressImpl.java:141）在 java.net.Inet6AddressImpl.lookupAllHostAddr（Inet6AddressImpl.java:90）在java.net.InetAddress.getAllByName（InetAddress.java：787）at com.android.okhttp.Dns $ 1.lookup（Dns.java:39）at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress（RouteSelector.java:175）在 com.android.okhttp.internal.http.RouteSelector.nextProxy（RouteSelector.java:141）在 com.android.okhttp.internal.http.RouteSelector.next（RouteSelector.java:83）在 com.android.okhttp.internal.http.StreamAllocation.findConnection（StreamAllocation.java:174）在 com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection（StreamAllocation.java:126）在 com.android.okhttp.internal.http.StreamAllocation.newStream（StreamAllocation.java:95）在 com.android.okhttp.internal.http.HttpEngine.connect（HttpEngine.java:281）在 com.android.okhttp.internal.http.HttpEngine.sendRequest（HttpEngine.java:224）在 com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute（HttpURLConnectionImpl.java:461）在 com.android.okhttp.internal.huc.HttpURLConnectionImpl.connect（HttpURLConnectionImpl.java:127）在 com.android.okhttp.internal.huc.HttpURLConnectionImpl.getOutputStream（HttpURLConnectionImpl.java:258）在 com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getOutputStream（DelegatingHttpsURLConnection.java:218）在 com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getOutputStream（未知资料来源：0）at com.tdameritrade.amerivest.clickstreamshared.Network.NetworkManager $ ClickstreamTask.doInBackground（NetworkManager.kt：87）在 com.tdameritrade.amerivest.clickstreamshared.Network.NetworkManager $ ClickstreamTask.doInBackground（NetworkManager.kt：43）在android.os.AsyncTask $ 2.call（AsyncTask.java:333）at java.util.concurrent.FutureTask.run（FutureTask.java:266）... 4更多引起：android.system.GaiException：android_getaddrinfo失败： EAI_NODATA（与主机名无关的地址）at libcore.io.Linux.android_getaddrinfo（Native Method）at libcore.io.ForwardingOs.android_getaddrinfo（ForwardingOs.java:59）at at java.net.Inet6AddressImpl.lookupHostByName（Inet6AddressImpl.java:122） ......还有24个

抛出异常的行是request.outputStream.write(httpBody)。但是，我们将该行包装在处理try / catch的{{1}}中。

如果Throwable第87行将其包裹在捕获中时如何抛出异常？

Answer 1

此代码：

    try{
        request.outputStream.write(httpBody)
    }catch (e: Throwable){
        request.outputStream.close()
        failure?.invoke(null, hashMapOf("error" to "Issue writing to URL"))
        return Unit
    }

将尝试在catch块中执行操作，该操作也会生成异常：

        request.outputStream.close()

这是未被捕获的 - 但如果您在访问输出流时处理某些错误，这似乎也是不明智的。

异常跟踪表示更多的原因造成的，并且我猜你还要进一步挖掘这个。

Android库在try块中抛出异常，捕获所有Throwable

1 个答案: