Class RequestRateThrottleFilter

  • All Implemented Interfaces:
    javax.servlet.Filter

    public class RequestRateThrottleFilter
    extends java.lang.Object
    implements javax.servlet.Filter
    A simple servlet filter that limits the request rate to a certain threshold of requests per second. The default rate is 5 hits in 10 seconds. This can be overridden in the web.xml file by adding parameters named "hits" and "period" with the desired values. When the rate is exceeded, a short string is written to the response output stream and the chain method is not invoked. Otherwise, processing proceeds as normal.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void destroy()
      Called by the web container to indicate to a filter that it is being taken out of service.
      void doFilter​(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)
      Checks to see if the current session has exceeded the allowed number of requests in the specified time period.
      void init​(javax.servlet.FilterConfig filterConfig)
      Called by the web container to indicate to a filter that it is being placed into service.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • RequestRateThrottleFilter

        public RequestRateThrottleFilter()
    • Method Detail

      • init

        public void init​(javax.servlet.FilterConfig filterConfig)
        Called by the web container to indicate to a filter that it is being placed into service. The servlet container calls the init method exactly once after instantiating the filter. The init method must complete successfully before the filter is asked to do any filtering work.
        Specified by:
        init in interface javax.servlet.Filter
        Parameters:
        filterConfig - configuration object
      • doFilter

        public void doFilter​(javax.servlet.ServletRequest request,
                             javax.servlet.ServletResponse response,
                             javax.servlet.FilterChain chain)
                      throws java.io.IOException,
                             javax.servlet.ServletException
        Checks to see if the current session has exceeded the allowed number of requests in the specified time period. If the threshold has been exceeded, then a short error message is written to the output stream and no further processing is done on the request. Otherwise the request is processed as normal.
        Specified by:
        doFilter in interface javax.servlet.Filter
        Parameters:
        request -
        response -
        chain -
        Throws:
        java.io.IOException
        javax.servlet.ServletException
      • destroy

        public void destroy()
        Called by the web container to indicate to a filter that it is being taken out of service. This method is only called once all threads within the filter's doFilter method have exited or after a timeout period has passed. After the web container calls this method, it will not call the doFilter method again on this instance of the filter.
        Specified by:
        destroy in interface javax.servlet.Filter