title: java.lang.IllegalArgumentException: Filter mapping specifies an unknown filter name <filtername
body: <p>I am getting the following exception</p>
  
  <pre><code>Caused by: java.lang.IllegalArgumentException: Filter mapping specifies an unknown filter name MyFilter
      at org.apache.catalina.core.StandardContext.validateFilterMap(StandardContext.java:3174)
      at org.apache.catalina.core.StandardContext.addFilterMap(StandardContext.java:3139)
      at org.apache.catalina.deploy.WebXml.configureContext(WebXml.java:1343)
      at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1362)
      at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:889)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:386)
      at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
      at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5472)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:147)
      ... 10 more
  </code></pre>
  
  <p>The filter is present in a jar file which is part of the delivered war.</p>
  
  <pre><code>@WebFilter(filterName="MyFilter",
          urlPatterns = {"/page/*"})
  public class myFilter implements Filter {
  </code></pre>
  
  <p>Can anybody tell me what i have to do that the filter can be found?</p>
  
  <p>it is not a duplicate of the question <a href="http://java.lang.IllegalArgumentException:%20The%20servlets%20named%20[X]%20and%20[Y]%20are%20both%20mapped%20to%20the%20url-pattern%20[/url]%20which%20is%20not%20permitted" rel="nofollow noreferrer">java.lang.IllegalArgumentException: The servlets named [X] and [Y] are both mapped to the url-pattern [/url] which is not permitted</a> because it is a very different error message</p>