Java 正在获取IOException，但没有错误消息

使用Android Studio 2.0

没有得到任何输出

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

在浏览器上使用内置URI可以得到正确的结果

在

urlConnection.connect（）之前调用getRequestMethod（）会给我方法名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/FetchWeatherTask:错误

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关于这个错误的信息。所以这一部分可以忽略。
你不接受这一行的异常吗？Log.e（Log_标签，“Error”，e）；如果已正确设置过滤器，则错误消息始终显示在logcat中。肯定还有更多…@Opiatefuchs我没有在logcat上使用任何过滤器。@RobertoDeLaParra我已经发布了，我在logcat上得到了什么。@RobertoDeLaParra如果你想让我在那里使用其他东西，请让我知道。是的……三星设备……我在三星galaxy s3上也遇到了一些问题……它有自己的生活，试图让你烦恼……@Opiatefuchs知道这些问题不是新的，但仍然没有解决，这很糟糕。@Opiatefuchs尝试以管理员的身份运行Android Studio，它确实比平时快，这是我在这期间注意到的，因为我花了将近6个小时。