Package org.opennms.web.servlet

Class AddRefreshHeaderFilter

  • All Implemented Interfaces:
    javax.servlet.Filter
    public class AddRefreshHeaderFilter
extends java.lang.Object
implements javax.servlet.Filter
    A filter that adds an HTTP Refresh header to a servlet or JSP's response. The amount of time to wait before refresh is configurable.
    Since:
    1.8.1
    Author:
    Lawrence Karnowski , OpenNMS

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected javax.servlet.FilterConfig filterConfig  
      protected java.lang.String seconds  

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void destroy()
      destroy
      void doFilter​(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)
      Adds a Refresh HTTP header before processing the request.
      void init​(javax.servlet.FilterConfig config)

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Field Detail

      • filterConfig

        protected javax.servlet.FilterConfig filterConfig

      • seconds

        protected java.lang.String seconds

    • Constructor Detail

      • AddRefreshHeaderFilter

        public AddRefreshHeaderFilter()

    • Method Detail

      • doFilter

        public void doFilter​(javax.servlet.ServletRequest request,
                     javax.servlet.ServletResponse response,
                     javax.servlet.FilterChain chain)
              throws java.io.IOException,
                     javax.servlet.ServletException
        Adds a Refresh HTTP header before processing the request.

        This is a strange implementation, because intuitively, you would add the header after the content has been produced (in other words, after you had already called FilterChain.doFilter. However, the Servlet 2.3 spec (proposed final draft) states (albeit in an off-handed fashion) that you can only "examine" the response headers after the doFilter call. Evidently this means that you cannot change the headers after the doFilter. If you call setHeader nothing happens.

        Specified by:
        doFilter in interface javax.servlet.Filter
        Throws:
        java.io.IOException
        javax.servlet.ServletException

      • init

        public void init​(javax.servlet.FilterConfig config)
        Specified by:
        init in interface javax.servlet.Filter

      • destroy

        public void destroy()

        destroy

        Specified by:
        destroy in interface javax.servlet.Filter