NoClassDefFoundError when running with Liquibase 2.x

[tony-pelton]

i'm trying to get a spring 4.x application onto spring-boot. a problem i've run into, is that you can't have Liquibase 2.x libraries on the classpath or spring-boot intialization fails.

`java.lang.NoClassDefFoundError: liquibase/servicelocator/CustomResolverServiceLocator

at org.springframework.boot.liquibase.LiquibaseServiceLocatorApplicationListener.onApplicationEvent(LiquibaseServiceLocatorApplicationListener.java:44)
at org.springframework.boot.liquibase.LiquibaseServiceLocatorApplicationListener.onApplicationEvent(LiquibaseServiceLocatorApplicationListener.java:35)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:122)
at org.springframework.boot.context.event.EventPublishingRunListener.starting(EventPublishingRunListener.java:68)
at org.springframework.boot.SpringApplicationRunListeners.starting(SpringApplicationRunListeners.java:48)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)`

the application listener does this :

if (ClassUtils.isPresent("liquibase.servicelocator.ServiceLocator", null)) { new LiquibasePresent().replaceServiceLocator(); }
the problem is, the class it is looking for exists in 2.x Liquibase, but the classes the "replacer" looks for don't.

and there is no switch to stop this from happening, since it is an application listener.

this is a problem for me, as i'd like to upgrade to 3.x, but i'm having trouble, and wanted to be able to do some testing with 2.x vs 3.x ... but this listener prevents me from having any control at all over whether i can have Liquibase 2.x on the classpath.

[wilkinsona]

Thanks for the analysis. We can tighten things up by checking for liquibase.servicelocator.CustomResolverServiceLocator. In the meantime, you can work around the problem with the following, slightly clunky approach:

SpringApplication application = new SpringApplication(SampleLiquibaseApplication.class);
application.setListeners(application.getListeners().stream()
	.filter((listener) -> !(listener instanceof LiquibaseServiceLocatorApplicationListener))
	.collect(Collectors.toSet()));
application.run(args);