To be able to secure Spring Boot apps you must add the Keycloak Spring Boot adapter JAR to your app. You then have to provide some extra configuration via normal Spring Boot configuration (application.properties). Let's go over these steps.

The Keycloak Spring Boot adapter takes advantage of Spring Boot's autoconfiguration so all you need to do is add the Keycloak Spring Boot adapter JAR to your project. Depending on what container you are using with Spring Boot, you also need to add the appropriate Keycloak container adapter. If you are using Maven, add the following to your pom.xml (using Tomcat as an example): org.keycloak keycloak-spring-boot-adapter &project.version; org.keycloak keycloak-tomcat8-adapter &project.version; ]]>

This section describes how to configure your Spring Boot app to use Keycloak. Instead of a keycloak.json file, you configure the realm for the Spring Boot Keycloak adapter via the normal Spring Boot configuration. For example: You also need to specify the J2EE security config that would normally go in the web.xml. Here's an example configuration: