title: How to handle "net::ERR_CONNECTION_REFUSED" in jsonp ajax
body: <p>Try best to describe my question:
  The following script is running at localhost:8080</p>
  
  <pre><code>$.ajax({
          type: "GET",
          url: 'http://localhost:8090/getinfo?index=' + index,
          dataType: "jsonp",
          jsonp: "callback",
          jsonpCallback: "success",
          success: function (data) {},
          error:function(){}
  })
  </code></pre>
  
  <p>If success, the return value is </p>
  
  <pre><code>success({"key":"value"})
  </code></pre>
  
  <p>However, if failed, console error in browser is
  <a href="https://i.stack.imgur.com/riEbi.png" rel="nofollow noreferrer">enter image description here</a>
  And I cannot handle it in error function. I even tried the .fail(function(){}) or setting "timeout" property, but it doesn't work either. Then how can I handle this error?</p>