Blu Age Tomcat server start error

Question

tomcat server start with 4.2.0 transform engine is resulting in the following exception. I suspect some WAR/JARs missing? please suggest possible misconfiguration or missing info.

2025-04-09T05:24:53.080Z INFO 5752 --- [ main] c.n.b.b.a.BACApplicationLauncher : >>> BUILD. INFO. : Using GapWalk build [4.2.0-90039e1e] <<< 2025-04-09T05:24:53.237Z INFO 5752 --- [ main] org.apache.jasper.servlet.TldScanner : At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time. 2025-04-09T05:24:53.237Z INFO 5752 --- [ main] o.a.c.c.C.[.[.[/carddemo-service] : No Spring WebApplicationInitializer types detected on classpath 2025-04-09T05:24:53.241Z ERROR 5752 --- [ main] o.a.c.c.C.[.[.[/carddemo-service] : Exception starting filter [ValidationFilter]

java.lang.ClassNotFoundException: aws.bluage.l3.workshop.servlet.ValidationFilter at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1444) at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1252) at org.apache.catalina.core.DefaultInstanceManager.loadClass(DefaultInstanceManager.java:535) at org.apache.catalina.core.DefaultInstanceManager.loadClassMaybePrivileged(DefaultInstanceManager.java:516) at org.apache.catalina.core.DefaultInstanceManager.newInstance(DefaultInstanceManager.java:150) at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:252) at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:103) at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4562) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5205) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:886) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75) at java.base/java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:145) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:263) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:927) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183) at org.apache.catalina.startup.Catalina.start(Catalina.java:795) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.base/java.lang.reflect.Method.invoke(Method.java:568) at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:345) at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:476)

2025-04-09T05:24:53.252Z ERROR 5752 --- [ main] o.apache.catalina.core.StandardContext : One or more Filters failed to start. Full details will be found in the appropriate container log file 2025-04-09T05:24:53.255Z ERROR 5752 --- [ main] o.apache.catalina.core.StandardContext : Context [/carddemo-service] startup failed due to previous errors About to detach context named carddemo

mahesh_anasuri · Answer

Issue got resolved and root cause is linked to missing few files from generate action outputs.

re:Post Agent · Answer

The error you're encountering when starting the Tomcat server with the 4.2.0 transform engine appears to be related to a missing class file. Specifically, the error indicates that the class "aws.bluage.l3.workshop.servlet.ValidationFilter" cannot be found.

This issue could be caused by several factors:

1. Missing JAR file: The JAR containing the ValidationFilter class may not be present in the WEB-INF/lib directory of your carddemo-service application.

2. Incorrect classpath: The JAR file might be present but not properly included in the classpath.

3. Incomplete deployment: The carddemo-service application may not have been fully or correctly deployed to the Tomcat server.

4. Misconfiguration in web.xml: The filter might be incorrectly defined in the web.xml file.

To resolve this issue, try the following steps:

1. Check the WEB-INF/lib directory of your carddemo-service application and ensure that all required JAR files are present, including the one containing the ValidationFilter class.

2. Review the web.xml file in the WEB-INF directory and verify that the ValidationFilter is correctly defined.

3. Ensure that the carddemo-service application is properly deployed to the Tomcat server.

4. Double-check the Tomcat server's classpath configuration to make sure it includes all necessary directories and JAR files.

5. If you're using Maven or Gradle for dependency management, verify that all required dependencies are correctly declared in your project's build file.

6. Try clearing Tomcat's work directory to ensure no stale compiled classes are interfering with the deployment.

If these steps don't resolve the issue, you may need to review the full Tomcat logs for more detailed error messages or consult the AWS Blu Age documentation for specific troubleshooting steps related to the 4.2.0 transform engine version.
      
**Sources**  
[AWS Blu Age Level 3 Self-Paced Troubleshooting Workshop > Automation > Execute > Run execute.xml Ant script | AWS re:Post](https://repost.aws/questions/QUJZu__lnwREa81h3X8KZ2zA/aws-blu-age-level-3-self-paced-troubleshooting-workshop-automation-execute-run-execute-xml-ant-script)  
[Tomcat isn't starting in AWS Blu Age L3 Workshop | AWS re:Post](https://repost.aws/questions/QUN-kiWNv4RuWWnh0dAhQ38A/tomcat-isn-t-starting-in-aws-blu-age-l3-workshop)

Blu Age Tomcat server start error

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