如何獲得在Java

-1

響應代碼，我想在我的程序響應代碼請你告訴我什麼是我下面的代碼如何獲得在Java

public class Main{ 
     public static void main(String args[]) throws Exception { 
     URL url = new URL("http://www.google.com"); 
     HttpURLConnection httpCon = openConnection(); 


     System.out.println("Response code is " + httpCon.getResponseCode()); 
    } 
    }

來源

2013-10-04 Rahul Patil

你看到了什麼錯誤？ – Reimeus

openConnection（）;你的意思是url.openConnection（）; ?? –

請給我們stacktrace /錯誤和'openConnection（）'的代碼' –

public class Main{ 
    public static void main(String args[]) throws Exception { 
    URL url = new URL("http://www.google.com"); 
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection(); 


    System.out.println("Response code is " + httpCon.getResponseCode()); 
} 
}

來源

2013-10-04 09:06:13

原因該問題的錯誤是編譯器告訴類構造函數（URL）和方法（openConnection ..）拋出異常（在它們的signatures中定義）並採取一些必要的步驟。

你有2種選擇：

Throw的檢查異常，從你的主要方法是。

public static void main(String[] args) throws IOException { 
      URL url = new URL("http://www.google.com"); 
      HttpURLConnection httpCon = (HttpURLConnection) url.openConnection(); 
       System.out.println("Response code is " + 
               httpCon.getResponseCode()); 
      }

或

聽清楚Exception，使用try catch block.

public static void main(String[] args) { 
     URL url; 
     HttpURLConnection httpCon; 
     try { 
      url = new URL("http://www.google.com"); 
      httpCon = (HttpURLConnection) url.openConnection(); 
      System.out.println("Response code is " + httpCon.getResponseCode()); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    }

來源

2013-10-04 09:07:02

你忘了把url 改變它HttpURLConnection httpCon = (HttpURLConnection) url.openConnection();

package naveed.workingfiles; 

import java.net.HttpURLConnection; 
import java.net.URL; 

public class Url { 

    public static void main(String args[]) throws Exception { 
     URL url = new URL("http://www.google.com"); 
     HttpURLConnection httpCon = (HttpURLConnection) url.openConnection(); 

     System.out.println("Response code is " + httpCon.getResponseCode()); 
    } 
}

來源

2013-10-04 09:08:05

嘗試鑄造對象HTTPU RLConnection

public class Main{ 
    public static void main(String args[]) throws Exception { 
    URL url = new URL("http://www.google.com"); 
    //Cast the object to HttpURLConnection 
    HttpURLConnection httpCon = (HttpURLConnection) url.openConnection(); 
    System.out.println("Response code is " + httpCon.getResponseCode()); 
} 
}

來源

2013-10-04 09:09:13

錯誤是顯而易見的人。

openConnection()是URL類的一種方法，並且未在您的類中定義。您必須使用您之前創建的URL類的對象。

電話的openConnection（）方法必須像這個 -

url.openConnection()它返回一個URLConnection對象，你將不得不此對象類型強制轉換爲HttpURLConnection。

來源

2013-10-04 09:13:03 Prasad

如何獲得在Java

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