Package alpine.server.filters

Class RequestRateThrottleFilter

java.lang.Object
alpine.server.filters.RequestRateThrottleFilter
All Implemented Interfaces:
javax.servlet.Filter
public final class RequestRateThrottleFilter extends Object implements javax.servlet.Filter
The RequestRateThrottleFilter is a Servlet filter that can place a hard limit on the number of requests per second. The filter conforms to RFC-6585 by sending HTTP status code 429 (too many requests) if the limit is exceeded. Sample usage: 
 <filter>
   <filter-name>RequestRateThrottleFilter</filter-name>
   <filter-class>alpine.filters.RequestRateThrottleFilter</filter-class>
   <init-param>
     <param-name>maximumRequestsPerPeriod</param-name>
     <param-value>5</param-value>
   </init-param>
   <init-param>
     <param-name>timePeriodSeconds</param-name>
     <param-value>10</param-value>
   </init-param>
 </filter>

 <!--  Place a request limit on all resources -->
 <filter-mapping>
   <filter-name>RequestRateThrottleFilter</filter-name>
   <url-pattern>/*</url-pattern>
 </filter-mapping>
Since:
1.0.0
Author:
Steve Springett

  • Constructor Summary

    Constructors
    Constructor
    Description
    RequestRateThrottleFilter()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    destroy()
    void
    doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)
    Determines if the request rate is below or has exceeded the the maximum requests per second for the given time period.
    void
    init(javax.servlet.FilterConfig filterConfig)

    Methods inherited from class java.lang.Object

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

  • Constructor Details

    • RequestRateThrottleFilter

      public RequestRateThrottleFilter()

  • Method Details

    • init

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

    • doFilter

      public void doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain) throws IOException, javax.servlet.ServletException
      Determines if the request rate is below or has exceeded the the maximum requests per second for the given time period. If exceeded, a HTTP status code of 429 (too many requests) will be send and no further processing of the request will be done. If the request has not exceeded the limit, the request will continue on as normal.
      Specified by:
      doFilter in interface javax.servlet.Filter
      Parameters:
      request - a ServletRequest
      response - a ServletResponse
      chain - a FilterChain
      Throws:
      IOException - a IOException
      javax.servlet.ServletException - a ServletException

    • destroy

      public void destroy()
      Specified by:
      destroy in interface javax.servlet.Filter