Udacity陽光 - 如何解決Android中的這個錯誤？未發現協議

Question

在Android上我越來越1日列表項的錯誤：java.net.MalformedURLException

java.net.MalformedURLException：協議沒有找到

這裏是我的來源：

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; 
     } 

    } 
} 

任何想法如何解決它？

Answer 1

我收到相同的錯誤。我認爲這是因爲2015年10月以來的API更改。

請嘗試不使用URi構建器類。我知道它不是構建url的正確方法，但是連接字符串不會產生錯誤。