指定默認值

 URL test = null; 
     String inputLine = null; 
     BufferedReader in = null; 
     try { 
      test = new URL("http://localhost/out.php"); // if connection down 
     } catch (MalformedURLException e) { 
      inputLine = "test_synntax"; 
     } 
     try { 
     in = new BufferedReader(new InputStreamReader(test.openStream())); 
     ...

如何，如果默認的URL解析失敗在好日子指定默認值

來源

2012-12-02 BJ_fr

問題你不清楚你要做什麼嗎？ –

並請形成適當的問題標題。 –

你在做什麼樣的工作呢？ – PermGenError

您需要調用URL.openConnection第一，然後把你的默認值在IOException塊：

try { 
    test = new URL("http://localhost/out.php"); 
    URLConnection urlConn = test.openConnection(); 
    in = new BufferedReader(new InputStreamReader(urlConn.getInputStream())); 
} catch (MalformedURLException e) { 
    inputLine = "test_synntax"; 
} catch (IOException e) { 
    inputLine = "test_synntax"; 
}

來源

2012-12-02 14:15:12 Reimeus

try { 
    test = new URL("http://localhost/out.php"); 
    //I believe you need this and it throws IOException on timeout. 
    //Though it's still unclear to me what you mean by 'resolution' and 'disponible wifi/3g`? 
    test.openConnection(); 
} catch (MalformedURLException | IOException e) { 
    inputLine = "test_synntax"; 
}

這個例子語境中不應WIFI/3G連接disponible，謝謝你們指定的inputline的價值是java的7多重捕獲語法，請介意。

來源

2012-12-02 14:11:32 nullpotent

-如果的WiFi/3G失敗，則它會給UnknownHostException。

所以，你可以處理他們這樣....

try { 
      test = new URL("http://localhost/out.php"); 

     } catch (UnknownHostException e) { 

      inputLine = "Connection error"; 
    }

來源

2012-12-02 14:11:42

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