Spring, Filters and Configuration easier than you think.

So I needed to add a filter for some cool stuff in my application.

First off I needed to get my filter to play nicely with Spring, so I needed to do the following in my web.xml

<filter>
  <filter-name>myCoolNewFilter</filter-name>
  <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
  <init-param>
    <param-name>targetBeanName</param-name>
    <param-value>myCoolNewFilterSpringBean</param-value>
  </init-param>
</filter>

So then I go ahead and open up my applicationContext.xml file and wire up the bean like normal

<bean name="myCoolNewFilterSpringBean" class="com.mycompany.filter.MyCoolNewFilter" />

Notice that the bean name in the app context matches the param-value in the filter config: myCoolNewFilterSpringBean

Then instead of trying to do URL patterns for the config of the filter I just tried the following:

<filter-mapping>
  <filter-name>myCoolNewFilterSpringBean</filter-name>
  <servlet-name>dispatcher</servlet-name>
</filter-mapping>

Which maps this filter to all filter all calls being directed to my dispatcher servlet! No nasty or convoluted URL patterns... Just easily readable servlet names!