使用OkHttpClient的奇怪连接阻塞/挂起

Question

我有一个由broadcastreceiver组成的应用程序，它在网络连接更改时被调用（基本上，我只想在连接到某个SSID时调用某些URL）。

我在挂起OkHttp请求时遇到了一个奇怪的问题。有时请求立即得到处理，有时需要10或20秒。我已经尝试为使用的OkHttpClient设置连接、读写超时，但没有成功。请求是在电话连接到网络之后发出的。我也尝试在延迟2秒的seperate线程中激发请求，但这并没有改变任何事情。

client = new OkHttpClient.Builder()
.writeTimeout(3, TimeUnit.SECONDS)
.readTimeout(3, TimeUnit.SECONDS)
.connectTimeout(3, TimeUnit.SECONDS)
.followRedirects(true)
.addNetworkInterceptor(new Interceptor() {
                @Override
                public Response intercept(Chain chain) throws IOException {
                    Request request = chain.request();
                    Log.d(TAG, "Request to URL: " + request.url());

                    Response response = chain.proceed(request);

                    return response;
                }
            })
.build();

public void onReceive(Context context, Intent intent) {
   /* ... */
   client.newCall(new Request.Builder()
                        .url(url)
                        .build()).enqueue(/* logging callback with
                        Log.d(TAG, response.toString()); on success*/);
}

货单中的接收者

        <receiver
        android:name=".WifiReceiver"
        android:enabled="true">
        <intent-filter>
            <action android:name="android.net.wifi.WIFI_STATE_CHANGED"/>
            <action android:name="android.net.conn.CONNECTIVITY_CHANGE"/>
        </intent-filter>
    </receiver>

Logcat结果，注意时差

11-24 22:19:49.717 17511 17511 I WifiReceiver:  -- Wifi connected ---
11-24 22:19:49.796 D WifiReceiver: Request to URL: http://172.217.22.78/
11-24 22:20:00.300 D WifiReceiver: Request to URL: http://www.google.com/
11-24 22:20:11.363 D WifiReceiver: Request to URL: http://www.google.de/?gfe_rd=cr&ei=gFk3WL3CDdHnugSQ262QCA
11-24 22:20:11.750 17511 18242 D WifiReceiver: Response{protocol=http/1.1, code=200, message=OK, url=http://www.google.de/SQ262QCA}

Answer 1

我刚刚验证了（通过添加一个自定义dns解析器）请求是否由于dns解析缓慢而阻塞。

11-24 22:29:39.317 D/WifiReceiver: Lookup 172.217.22.78
11-24 22:29:39.372 D/WifiReceiver: Request to URL: http://172.217.22.78/
11-24 22:29:39.425 D/WifiReceiver: Lookup www.google.com
11-24 22:29:49.953 D/WifiReceiver: Request to URL: http://www.google.com/
11-24 22:29:50.291 D/WifiReceiver: Lookup www.google.de
11-24 22:30:00.775 D/WifiReceiver: Request to URL: http://www.google.de/?gfe_rd=cr&ei=zVs3WLmoNdPLugTk8IKoCA
11-24 22:30:01.197 D/WifiReceiver: Response{protocol=http/1.1, code=200, message=OK, url=http://www.google.de/?gfe_rd=cr&ei=zVs3WLmoNdPLugTk8IKoCA}