Compatibility Issue: Spring Boot 3.4.2/Java 21 on WebLogic 14.1.2 – REST Endpoints Returning 404

I am experiencing an issue deploying our application on WebLogic Server 14.1.2 using Java 21 and Spring Boot 3.4.2.

Initially, I encountered a ClassNotFoundException for jakarta.servlet.jsp.tagext.DynamicAttributes during deployment. I resolved this by adding the following dependencies to our pom.xml:

<dependency>

    <groupId>jakarta.servlet</groupId>

    <artifactId>jakarta.servlet-api</artifactId>

    <version>6.1.0</version>

</dependency>

<dependency>

    <groupId>jakarta.servlet.jsp</groupId>

    <artifactId>jakarta.servlet.jsp-api</artifactId>

    <version>3.1.1</version>

</dependency>

After these changes, the application deploys successfully, and static resources (like an index.html in the webapp folder) are served without issues. However, any Spring Boot REST endpoints (for example, one mapped at