solr对空索引字段的行为如何？(How solr behaves for empty index fields?)

 您必须使用[]方括号来转义格式字符串中的字符，请参阅format文档： 
 
 
 
 要转义格式字符串中的字符，可以将字符包装在方括号中。 
 
 
 此外请注意，目前没有EEEE令牌，但单个E代表星期几（ISO） ，因此在您的情况下，您将拥有2222 。 使用dddd获取所需的输出。 
 
 这是一个工作示例： 
 
 
 
 
 
  
var date = '2017-01-02';
var format = 'dddd, D [de] MMMM [de] YYYY';
console.log(moment(date).format(format));
 
  
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/locale/pt.js"></script>
 
 
 
 

You have to use [] square brackets to escape characters in format string, see format docs:
 
 
 
To escape characters in format strings, you can wrap the characters in square brackets.
 
 
Moreover note that there is no EEEE token in moment, but the single E represents Day of Week (ISO), so in your case you will have 2222. Use dddd to get the desidered output.
 
Here a working example:
 
 
 
 
 
  
var date = '2017-01-02';
var format = 'dddd, D [de] MMMM [de] YYYY';
console.log(moment(date).format(format));
 
  
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/locale/pt.js"></script>