java - java中的URL连接

Question

我有一个 ArrayList，其中包含以下格式的网站列表:-

• google.com
• facebook.com
• youtube.com
• yahoo.com
• wikipedia.org

• t.co

  我必须从所有链接中读取 html 文本。但有些链接会产生问题，例如 (t.co)，而其他链接则工作正常。

  代码:-

             try
                    {
                      String line="t.co";
                      String[] Add_words = line.split("[//:.]");
                      if (Add_words[0].contains("http")) {
  
                      }
  
                      else if (Add_words[0].contains("www"))
                          line = "http://" + line;
                      else if (!Add_words[0].contains("http")
                              && !Add_words[0].contains("www"))
                          line = "http://www." + line;
  
  
                       URL url = new URL(line);
                       URLConnection urlConnection = url.openConnection();
                       HttpURLConnection connection = null;
                       if(urlConnection instanceof HttpURLConnection)
                       {
                          connection = (HttpURLConnection) urlConnection;
                       }
                       else
                       {
                          System.out.println("Please enter an HTTP URL.");
                          return;
                       }
                       BufferedReader in = new BufferedReader(
                       new InputStreamReader(connection.getInputStream()));
                       String urlString = "";
                       String current;
                       while((current = in.readLine()) != null)
                       {
                          urlString += current+"\n";
                       }
                       System.out.println(urlString);
                    }catch(IOException e)
                    {
                       e.printStackTrace();
                    }
  
  
  And I'm getting the error with the last link `t.co`
  

  错误:-

  java.io.FileNotFoundException: http://www.t.co
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream0(HttpURLConnection.java:1834)
      at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1439)
      at com.test.code.Main.main(Main.java:109)
  

  我需要的是，我有上述格式的链接列表，并且我的代码应该访问所有链接，无论链接格式是什么。

Answer 1

您正在将 www. 添加到 t.co，但 www.t.co 不正确，将导致 404 未找到。

只需不要将 www. 添加到 URL 中即可。