title: HTTP request to 127.0.0.1:80 fails
body: <p><strong>Environment</strong></p>
  
  <ul>
  <li>Android Studio latest release</li>
  <li>Android Emulator running Android Nougat</li>
  <li>MAMP to serve as HTTP server</li>
  </ul>
  
  <p><strong>Problem</strong></p>
  
  <p>My simple method </p>
  
  <pre><code>  Future&lt;String&gt; _getSimpleReply( String command, callback, errorCallback ) async {
  
      try {
  
        HttpClientRequest request = await _myClient.get( '127.0.0.1', 80 '/' );
        HttpClientResponse response = await request.close();
        await callback( response.toString() );
  
      } on SocketException catch( e ) {
  
        errorCallback( e.toString() );
  
      }
  
    }
  </code></pre>
  
  <p>fails with an error:</p>
  
  <pre><code>cbLoginFailed :: SocketException: OS Error: 
    Connection refused, errno = 111, address = 127.0.0.1, port = 46414
  </code></pre>
  
  <p>Currently using the Android emulator, which has been configured for internet access:</p>
  
  <pre><code>&lt;uses-permission android:name="android.permission.INTERNET"/&gt;
  </code></pre>
  
  <p>For test purpose, the HTTP server is MAMP, which executes the index.php script and <strong>returns some simple string</strong>, if I enter this link in a browser:</p>
  
  <pre><code>http://127.0.0.1/index.php
  </code></pre>
  
  <p>The situation <strong>does not change</strong>, if I replace 127.0.0.1 with localhost.</p>
  
  <p>But if I do change 127.0.0.1 with a valid <strong>public FQDN</strong>, the method works just fine:</p>
  
  <pre><code>doLoginSuccess :: Instance of '_HttpClientResponse'
  </code></pre>
  
  <p><strong>Question</strong></p>
  
  <ol>
  <li><p>Why does the android emulator / flutter / dart handles 127.0.0.1 different than a
  valid FQDN?</p></li>
  <li><p>And how to I change this behaviour?</p></li>
  </ol>