How to handle net::ERR_CONNECTION_REFUSED in Angular2 : <p><a href="https://angular.cn/docs/ts/latest/guide/server-communication.html#!#error-handling" rel="noreferrer">error-handling</a> shows how to handle errors as follows:</p>

<pre><code>private handleError (error: Response | any) {
  // In a real world app, we might use a remote logging infrastructure
  let errMsg: string;
  if (error instanceof Response) {
    const body = error.json() || '';
    const err = body.error || JSON.stringify(body);
    errMsg = `${error.status} - ${error.statusText || ''} ${err}`;
  } else {
    errMsg = error.message ? error.message : error.toString();
  }
  console.error(errMsg);
  return Promise.reject(errMsg);
}
</code></pre>

<p>I'd like to access an API server, but the server hasn't started. Then I got the error:</p>

<pre><code>http://localhost:3000/api/heroes net::ERR_CONNECTION_REFUSED
</code></pre>

<p>I need to <strong>tell the user politely that the API server hasn't started</strong>. How should I handle the error?</p>

<p>The error Response is:</p>

<pre><code>_body:ProgressEvent
headers:Headers
ok:false
status:0
statusText:""
type:3
url:null
</code></pre>

<p>Could I handle this according to the <strong>status</strong> of the response?</p>
