spring boot +spring security+thymeleaf 报CSRF错误

Invalid CSRF Token 'null' was found on the request parameter '_csrf' or header 'X-CSRF-TOKEN'.

需在页面上添加两段代码

1.在标签中添加

<meta name="_csrf" th:content="${_csrf.token}"/>

<meta name="_csrf_header" th:content="${_csrf.headerName}"/>

2.在
标签中添加

<input type="hidden"
       th:name="${_csrf.parameterName}"
       th:value="${_csrf.token}"/>