nutzwk 将baseMode 中字段 opat的类型由int改为date 抛下面的异常是怎么回事？

HTTP Status 500 - Filtered request failed.

type Exception report
message Filtered request failed.
description The server encountered an internal error that prevented it from fulfilling this request.
exception
javax.servlet.ServletException: Filtered request failed.
	org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:384)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
root cause
org.apache.shiro.cache.CacheException: java.lang.ClassCastException: cannot assign instance of java.lang.Integer to field com.nutz.base.model.BaseModel.opAt of type java.util.Date in instance of com.nutz.tiles.authority.entity.Authority
	org.apache.shiro.cache.ehcache.EhCache.get(EhCache.java:85)
	org.apache.shiro.session.mgt.eis.CachingSessionDAO.getCachedSession(CachingSessionDAO.java:217)
	org.apache.shiro.session.mgt.eis.CachingSessionDAO.getCachedSession(CachingSessionDAO.java:202)
	org.apache.shiro.session.mgt.eis.CachingSessionDAO.readSession(CachingSessionDAO.java:259)
	org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSessionFromDataSource(DefaultSessionManager.java:236)
	org.apache.shiro.session.mgt.DefaultSessionManager.retrieveSession(DefaultSessionManager.java:222)
	org.apache.shiro.session.mgt.AbstractValidatingSessionManager.doGetSession(AbstractValidatingSessionManager.java:118)
	org.apache.shiro.session.mgt.AbstractNativeSessionManager.lookupSession(AbstractNativeSessionManager.java:108)
	org.apache.shiro.session.mgt.AbstractNativeSessionManager.getSession(AbstractNativeSessionManager.java:100)
	org.apache.shiro.mgt.SessionsSecurityManager.getSession(SessionsSecurityManager.java:125)
	org.apache.shiro.mgt.DefaultSecurityManager.resolveContextSession(DefaultSecurityManager.java:456)
	org.apache.shiro.mgt.DefaultSecurityManager.resolveSession(DefaultSecurityManager.java:442)
	org.apache.shiro.mgt.DefaultSecurityManager.createSubject(DefaultSecurityManager.java:338)
	org.apache.shiro.subject.Subject$Builder.buildSubject(Subject.java:846)
	org.apache.shiro.web.subject.WebSubject$Builder.buildWebSubject(WebSubject.java:148)
	org.apache.shiro.web.servlet.AbstractShiroFilter.createSubject(AbstractShiroFilter.java:292)
	org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:359)
	org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125)
root cause