使用错误代码到指定页面
<error-page>
<location>/404.html</location>
</error-page>
使用异常处理javax.servlet.ServletException
1、将异常抛给容器throw new ServletException(e);
2、在web.xml中配置
<error-page>
<exception-type>javax.servlet.ServletException</exception-type>
<location>/error2.jsp</location>
</error-page>