Java Servlet Filter Adapter

If you want to use SAML with a Java servlet application that doesn’t have an adapter for that servlet platform, you can opt to use the servlet filter adapter that Keycloak has. This adapter works a little differently than the other adapters. You still have to specify a /WEB-INF/keycloak-saml.xml file as defined in the General Adapter Config section, but you do not define security constraints in _web.xml. Instead you define a filter mapping using the Keycloak servlet filter adapter to secure the url patterns you want to secure.

Note
Backchannel logout works a bit differently than the standard adapters. Instead of invalidating the http session it instead marks the session ID as logged out. There’s just no way of arbitrarily invalidating an http session based on a session ID.
Warning
Backchannel logout does not currently work when you have a clustered application that uses the SAML filter.
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
      version="3.0">

	<module-name>customer-portal</module-name>

    <filter>
        <filter-name>Keycloak Filter</filter-name>
        <filter-class>org.keycloak.adapters.saml.servlet.SamlFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>Keycloak Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

The Keycloak filter has the same configuration parameters available as the other adapters except you must define them as filter init params instead of context params.

You can define multiple filter mappings if you have various different secure and unsecure url patterns.

Warning
You must have a filter mapping that covers /saml. This mapping covers all server callbacks.

When registering SPs with an IdP, you must register http[s]://hostname/{context-root}/saml as your Assert Consumer Service URL and Single Logout Service URL.

To use this filter, include this maven artifact in your WAR poms:

<dependency>
   <groupId>org.keycloak</groupId>
   <artifactId>keycloak-saml-servlet-filter-adapter</artifactId>
   <version>3.2.1.Final</version>
</dependency>