Deploying Spring Boot app to AWS beanstalk

Question

I am trying since yesterday to deploy a spring boot in Tomcat on AWS Beanstalk and I always have this exception being raised :

    Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'errorPageFilter': Initialization of bean failed;
      .....

       Caused by: java.lang.ClassCastException: org.springframework.boot.context.web.ErrorPageFilter cannot be cast to org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory
        at org.coursera.symptomserver.auth.config.OAuth2SecurityConfiguration$1.customize(OAuth2SecurityConfiguration.java:212)
        at org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizerBeanPostProcessor.postProcessBeforeInitialization(EmbeddedServletContainerCustomizerBeanPostProcessor.java:67)
        at org.springframework.boot.context.embedded.EmbeddedServletContainerCustomizerBeanPostProcessor.postProcessBeforeInitialization(EmbeddedServletContainerCustomizerBeanPostProcessor.java:54)
 ...

In my local dev environment, I don't have this error. In my local dev, I developped on Tomcat 7 with the '1.0.2.RELEASE' version.

I created a war with that I deploy on Tomcat 7 instance in AWS Beanstalk and the error below always comes out. How can I fix this error?

Answer 1

When you deploy a Spring Boot application to a standalone servlet container, it uses a special "embedded" servlet container, ErrorPageFilter , to handle application errors by forwarding requests to the configured error pages. The code in org.coursera.symptomserver.auth.config.OAuth2SecurityConfiguration$1 is incorrectly assuming that this class is a org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory which is resulting in a ClassCastException .

The first thing to do is to make this code more robust by adding an instanceof check so that it only attempts the cast when it knows that it'll succeed. Secondly, as you're actually deploying to a standalone Tomcat instance, you'll need to apply this customisation to Tomcat by changing its server.xml or context.xml rather than doing it programatically.