Root Cause:
org.apache.shiro.UnavailableSecurityManagerException: No SecurityManager accessible to the calling code, either bound to the org.apache.shiro.util.ThreadContext or as a vm static singleton. This is an invalid application configuration.
网上搜罗来的解释说是web.xml少了这一段, 但是我有:
<!-- 配置shiro的核心拦截器 -->
<filter>
<filter-name>shiroFilter</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>shiroFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
后来发现是还少了几行, 完整体应该是:
<!-- 配置shiro的核心拦截器 -->
<filter>
<filter-name>shiroFilter</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<filter-mapping>
<filter-name>shiroFilter</filter-name>
<url-pattern>/*</url-pattern>
<dispatcher>REQUEST</dispatcher>
<dispatcher>FORWARD</dispatcher>
<dispatcher>INCLUDE</dispatcher>
<dispatcher>ERROR</dispatcher>
</filter-mapping>
表示这4种都要经过shiro拦截器。我之前配置的404页面里回去访问shiro的SecurityUtils.getSubject(),若error不被拦截, 则这个请求是无法获取Subject的, 因此报错