title: Jackson - Serialize ZonedDateTime to ISO 8601 String
body: <p>I want to serialize a <code>ZonedDateTime</code> to an <strong>ISO 8601</strong> compliant String, e.g.:<br>
  <code>2018-02-14T01:01:02.074+0100</code>.</p>
  
  <p>I tried the following:</p>
  
  <pre><code>@JsonProperty("@timestamp")
  @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "yyyy-MM-dd'T'HH:mm:ss.SSSXXX")
  private ZonedDateTime timestamp;
  </code></pre>
  
  <p>But unfortunately it does not give the correct result and serializes the <code>ZonedDateTime</code> with all its fields, etc.</p>
  
  <p>Thank you already for your help!</p>