java.net.MalformedURLExceptionを取得し続ける：変数を使用してURLを設定するときにプロトコルがありません

Question

文字列からURLに変更しようとすると、URL上でプロトコルが取得されません。どんな助けでも大歓迎です！

icon_image = weather.weather_pic(); 
//^ The string icon_image is = http://icons.wxug.com/i/c/k/clear.gif 

URL url = new URL("http://icons.wxug.com/i/c/k/clear.gif"); 


// when I try URL url = new URL(icon_image); it gives me malformed unknown protocal. 
// but if i set it like this URL url = new URL("http://icons.wxug.com/i/c/k/clear.gif") it works ?? 

私はそのは

public static String weather_pic() throws IOException { 

    // Connect to the URL using java's native library 
    String sURL = "http://api.wunderground.com/api/84b167e6ec916b78/conditions/q/NV/Reno.json"; //just a string 
    URL url = null; 
    try { 
     url = new URL(sURL); 
    } catch (MalformedURLException e) { 
     e.printStackTrace(); 
    } 
    HttpURLConnection request = null; 
    try { 
     request = (HttpURLConnection) url.openConnection(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
    try { 
     request.connect(); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    // Convert to a JSON object to print data 
    JsonParser jp = new JsonParser(); //from gson 
    JsonElement root = null; //Convert the input stream to a json element 
    try { 
     root = jp.parse(new InputStreamReader((InputStream) request.getContent())); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

    JsonObject rootobj = root.getAsJsonObject(); //May be an array, may be an object. 

    JsonObject cond = rootobj.get("current_observation").getAsJsonObject(); 

    String icon = cond.get("icon_url").toString(); 

    System.out.println(icon); 
    //String zipcode = rootobj.get("query").getAsString(); //just grab the zipcode 
    String icon_x = icon; 



    return icon_x; 
} 

をやって何を表示するためにweather_pic追加のは、実際に値を持っており、それはあなたが好き"で文字列の結果を取り囲んcond.get("icon_url").toString()を使用している

Exception in thread "main" java.net.MalformedURLException: no protocol: "http://icons.wxug.com/i/c/k/partlycloudy.gif" 
    at java.net.URL.<init>(URL.java:593) 
    at java.net.URL.<init>(URL.java:490) 
    at java.net.URL.<init>(URL.java:439) 
    at widget.Widget.<init>(Widget.java:42) 
    at widget.Widget.main(Widget.java:75) 
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 
    at java.lang.reflect.Method.invoke(Method.java:498) 
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:147) 
"http://icons.wxug.com/i/c/k/partlycloudy.gif" 

Process finished with exit code 1 

Answer 1

を行うかどうかを確認あなたの場合：

"http://icons.wxug.com/i/c/k/partlycloudy.gif" 
^           ^

URLがプロトコル名の代わりに開始時に"を見つけたら、それについて文句を言います。その問題を解決し、

cond.get("icon_url").getAsString();