springboot ClassNotFoundException: com. ibm.ws.bootstrap.RASWsLoggerFactory

The `ClassNotFoundException` you're encountering in a Spring Boot application is related to the IBM WebSphere Resource Adapter (WSRA). It seems that your application is trying to load the `com.ibm.ws.rsadapter.spi.WSResourceAdapterImpl` class, which is part of the WebSphere-specific library but cannot be found by the ClassLoader[^1].

This error typically occurs when there's an issue with the classpath setup or missing dependencies required by the IBM WebSphere components. In the given context, the problem concludes that the fix for this issue prevents synchronization of invalid configuration on older versions (6.1 and earlier), suggesting that the necessary classes may not be available or compatible with the version of your application[^2].

To resolve this issue, follow these steps:

1. **Check dependencies**: Ensure that your project includes the correct dependency for the IBM WebSphere Resource Adapter. If using Spring Boot, you might need to add the `spring-boot-starter-jee` or a specific starter for WebSphere.

   <!-- Add in Maven pom.xml -->
   <dependency>
       <groupId>org.springframework.boot</groupId>
       <artifactId>spring-boot-starter-jee</artifactId>
   </dependency>

2. **Add WebSphere libraries**: Include the appropriate JAR files for WebSphere into your classpath, either by adding them as local dependencies or configuring your build tool (e.g., Maven or Gradle) to fetch them transitively.

3. **Configure classloader isolation**: Depending on your application architecture, you may need to configure classloader isolation settings in Spring Boot if WebSphere libraries are managed separately.

4. **Verify version compatibility**: Ensure that the version of WebSphere libraries you're using matches or is compatible with your Spring Boot version and the WebSphere adapter version you've added.

5. **Update to the fixed version**: If possible, upgrade to the fix pack mentioned (7.0.0.3) or later, as it addresses this issue.

Remember to consult the official documentation for your WebSphere environment and Spring Boot integration for the most up-to-date instructions[^3].