web.xml中配置OpenEntityManagerInView

<!--把数据库的连接开到了表现层,不会出现数据的延迟加载-->

<filter>
  <filter-name>OpenEntityManagerInView</filter-name>
  <filter-class>org.springframework.orm.jpa.support.OpenEntityManagerInViewFilter</filter-class>
 </filter>
 
 <filter-mapping>
  <filter-name>OpenEntityManagerInView</filter-name>
  <url-pattern>/*</url-pattern>
 </filter-mapping>