[Tomcat] Liquibase failed to start

Hi there.

I've app project on spring-boot generated by JHipster along with Liquibase 3.4.2. Application works fine if launched by java -jar command but fails to start on tomcat server.

Stacktrace (full in attachment):

1. SEVERE 10.08.16 17:46: liquibase: Cannot build ServiceLocator
   java.lang.NullPointerException
       at liquibase.resource.AbstractResourceAccessor.addRootPath(AbstractResourceAccessor.java:46)
       at liquibase.resource.AbstractResourceAccessor.init(AbstractResourceAccessor.java:33)
       at liquibase.resource.ClassLoaderResourceAccessor.<init>(ClassLoaderResourceAccessor.java:21)
       at liquibase.servicelocator.ServiceLocator.<init>(ServiceLocator.java:49)
       at liquibase.servicelocator.ServiceLocator.<clinit>(ServiceLocator.java:33)
   

After some investigation I've found this code in AbstractResourceAccessor:

1. baseUrls = classLoader.getResources("");

Classloader instance provided by org.apache.catalina.loader.WebappClassLoader. It returns some enumeration with null in the end. So when liquibase execute further code: 

1.     protected void addRootPath(URL path) {
           String externalForm = path.toExternalForm();

It fails with null pointer exception. How it's even possible? It's fault of tomcat, liquibase or my config? Please help to resolve this sutiation.