There was an unexpected error (type=Method Not Allowed, status=405). Request method 'POST' not supported

背景：点击提交按钮ajax请求接口时，报出错误【

Whitelabel Error Page

This application has no explicit mapping for /error, so you are seeing this as a fallback.

Thu Jun 06 14:49:25 CST 2019

There was an unexpected error (type=Method Not Allowed, status=405).

Request method 'POST' not supported

】

原因：从字面意思看是提交方式错误，该错误提示极具迷惑性，实际是由于submit事件最后没有return false;导致的。ajax会提交一次，form表单自带的submit按钮也会提交，在onclick事件最后加上return false;form表单就不会再提交，不然就是提交两次，所以报上面那个错。

方法：