this is how url should be appended

URIBuilder.java

// Will contain the raw JSON response as a string.
            String forecastJsonStr = null;
            String format = "json";
            String units = "metric";
            int numDays = 7;

            
                // Construct the URL for the OpenWeatherMap query
                // Possible parameters are avaiable at OWM's forecast API page, at
                // http://openweathermap.org/API#forecast
                //URL url = new URL("http://api.openweathermap.org/data/2.5/forecast/daily?q=94043&mode=json&units=metric&cnt=7");
                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";

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