How to detect the database for JDBC Realm is down

[Ivan Cheung]

Hi,

I am building a web app and have setup digest authentication

I am testing the app when I take the database that contains the username
password down

The tomcat log file show this

(http-8443-Processor25) org.apache.catalina.core.ContainerBase.[Catalina]:
Exception performing authentication {
java.sql.SQLException: No operations allowed after connection closed.
    at com.mysql.jdbc.Connection.checkClosed(Connection.java:2647)
    at com.mysql.jdbc.Connection.commit(Connection.java:1039)
    at org.apache.catalina.realm.JDBCRealm.getPassword(JDBCRealm.java:563)
    at org.apache.catalina.realm.RealmBase.getDigest(RealmBase.java:1091)

I have setup the WEB-INF/web.xml to trap this exception to show a custom
error page

  <error-page>
    <exception-type>java.sql.SQLException</exception-type>
    <location>/server_rdbms_error.html</location>
  </error-page>

however tomcat is not showing the custom error page and it keep popping up
the login page over and over again.

I was wondering if someone can tell me what is the proper way to setup the
custom error page when the database is down and authentication fail.

Thanks,
Ivan