Udacity Sunshine - 如何在Android中解决此错误？ java.net.MalformedURLException：找不到协议

Question

在Android上我在第一个列表项上收到错误：

  

java.net.MalformedURLException：未找到协议

这是我的来源：

package com.example.android.sunshine.app;

import android.net.Uri;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

/**
 * A placeholder fragment containing a simple view.
 */
public class ForecastFragment extends Fragment {

    private ArrayAdapter<String> mForecastAdapter;

    public ForecastFragment() {
    }
    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }
    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater){
        inflater.inflate(R.menu.forecastfragment, menu);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item){
        int id = item.getItemId();
        if(id == R.id.action_refresh){
            FetchWeatherTask weatherTask = new FetchWeatherTask();
            weatherTask.execute("94043");
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);

        String[] forecastArray = {
                "Today - Sunny - 88/63",
                "Tomorrow - Foggy - 70/40",
                "Wed - Sunny - 87/10",
                "Thu - Snowy - 104/150",
                "Fri - Boomy - 78/67",
                "Sat - CYCLONE - 60/51",
                "Sun - Sunny - 80/20"
        };

        List<String> weekforecast = new ArrayList<String>(
                Arrays.asList(forecastArray)
        );

        mForecastAdapter =
                new ArrayAdapter<String>(
                        getActivity(),
                        R.layout.list_item_forecast,
                        R.id.list_item_forecast_textview,
                        weekforecast
                );

        ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
        listView.setAdapter(mForecastAdapter);

        return rootView;
    }
    public class FetchWeatherTask extends AsyncTask<String, Void, Void>   {

        private final String LOG_TAG = FetchWeatherTask.class.getSimpleName();

        @Override
        protected Void doInBackground(String... params){
            // These two need to be declared outside the try/catch
// so that they can be closed in the finally block.
            HttpURLConnection urlConnection = null;
            BufferedReader reader = null;

// Will contain the raw JSON response as a string.
            String forecastJsonStr = null;
            String format ="json";
            String units = "metric";
            int numDays = 7;
            String appid = "86d7b4ab211c2b707e68fdf9e4a2e628";

            try {
                // Construct the URL for the OpenWeatherMap query
                // Possible parameters are available 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 Unit_Param = "units";
                final String Days_Param = "cnt";
                final String Api_Key = "APPID";

                Uri builtUri = Uri.parse(ForeCast_Base_URL).buildUpon()
                        .appendQueryParameter(Query_Param,params[0])
                        .appendQueryParameter(Format_Param,format)
                        .appendQueryParameter(Unit_Param, units)
                        .appendQueryParameter(Days_Param, Integer.toString(numDays))
                        .appendQueryParameter(Api_Key,appid)
                        .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();

                // Read the input stream into a String
                InputStream inputStream = urlConnection.getInputStream();
                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,"Forecast JSON String: " +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 attempting
                // 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);
                    }
                }
            }
            return null;
        }

    }
}

知道怎么解决吗？

Answer 1

我收到同样的错误。我认为这是因为自2015年10月以来的API变化。

尝试不使用URi构建器类。我知道它不是构建URL的正确方法，但连接字符串不会产生错误。