获取 IOException 且没有错误消息 Android

Question

使用 Android Studio 2.0

没有输出

Log.v(LOG_TAG, "Response Code" + urlConnection.getResponseCode());
Log.v(LOG_TAG, "Error Stream" + urlConnection.getErrorStream());
Log.v(LOG_TAG, "Request Method" + urlConnection.getRequestMethod());    

在浏览器上使用 Built URI 可以得到正确的结果。

在 urlConnection.connect(); 调用 getRequestMethod() 之前给我方法名称 GET 。

代码

try {
    // Construct the URL for the OpenWeatherMap query
    // Possible parameters are avaiable at OWM's forecast API page, at
    // http://openweathermap.org/API#forecast
    final String FORECAST_BASE_URL = "http://api.openweathermap.org/data/2.5/forecast/daily?";
    final String QUERY_PARAM = "q";
    final String FORMAT_PARAM = "mode";
    final String UNITS_PARAM = "units";
    final String DAYS_PARAM = "cnt";
    final String APPID_PARAM = "APPID";

    Uri builtUri = Uri
            .parse(FORECAST_BASE_URL)
            .buildUpon()
            .appendQueryParameter(QUERY_PARAM, params[0])
            .appendQueryParameter(FORMAT_PARAM, format)
            .appendQueryParameter(UNITS_PARAM, units)
            .appendQueryParameter(DAYS_PARAM, Integer.toString(numDays))
            .appendQueryParameter(APPID_PARAM,
                    BuildConfig.OPEN_WEATHER_MAP_API_KEY).build();

    URL url = new URL(builtUri.toString());

    Log.v(LOG_TAG, "Built URI " + builtUri.toString());

    // Create the request to OpenWeatherMap, and open the connection
    urlConnection = (HttpURLConnection) url.openConnection();
    // urlConnection.setRequestMethod("GET");
    urlConnection.connect();
    Log.v(LOG_TAG, "Response Code" + urlConnection.getResponseCode());
    Log.v(LOG_TAG, "Error Stream" + urlConnection.getErrorStream());
    Log.v(LOG_TAG, "Request Method" + urlConnection.getRequestMethod());

    // Read the input stream into a String
    // InputStream inputStream = urlConnection.getInputStream();
    InputStream inputStream;
    if (urlConnection.getResponseCode() >= 400) {
        inputStream = urlConnection.getErrorStream();
    } else {
        inputStream = urlConnection.getInputStream();
    }
    // Log.v(LOG_TAG, "Response Code" +urlConnection.getHeaderFields());

    StringBuffer buffer = new StringBuffer();
    if (inputStream == null) {
        // Nothing to do.
        return null;
    }
    reader = new BufferedReader(new InputStreamReader(inputStream));

    String line;
    while ((line = reader.readLine()) != null) {
        // Since it's JSON, adding a newline isn't necessary (it won't
        // affect parsing)
        // But it does make debugging a *lot* easier if you print out
        // the completed
        // buffer for debugging.
        buffer.append(line + "\n");
    }

    if (buffer.length() == 0) {
        // Stream was empty. No point in parsing.

        return null;
    }
    forecastJsonStr = buffer.toString();
    Log.v(LOG_TAG, "JSON Response " + forecastJsonStr);
} catch (IOException e) {
    Log.e(LOG_TAG, "Error", e);
    // If the code didn't successfully get the weather data, there's no
    // point in attemping
    // to parse it.
    return null;
} finally {
    if (urlConnection != null) {
        urlConnection.disconnect();
    }
    if (reader != null) {
        try {
            reader.close();
        } catch (final IOException e) {
            Log.e(LOG_TAG, "Error closing stream", e);
        }
    }
}

错误日志

04-22 18:42:16.444 9011-9011/com.android.serverwarrior.sunshine E/ViewRootImpl: sendUserActionEvent() mView == null

04-22 18:42:17.405 9011-9314/com.android.serverwarrior.sunshine E/FetchWeatherTask：错误

Answer 1

不知道，但是，我将手机连接到 wifi 网络，然后再次发送请求，我得到了 JSON 响应。

我确认了，没有网络连接，我没有得到输出。

关于

04-22 18:42:16.444 9011-9011/com.android.serverwarrior.sunshine E/ViewRootImpl: sendUserActionEvent() mView == null

这是因为三星设备，我从其他帖子中得到的这个错误。所以这部分可以忽略。