I have a sample Spring Boot application (available at https://github.com/dankelleher/UndertowFilterTester) which registers programmatically (no web.xml) two filters, one mapped by servlet name, and one by url pattern.

On startup I get the following exception:

java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.springframework.boot.maven.RunMojo$LaunchRunner.run(RunMojo.java:418)
at java.lang.Thread.run(Thread.java:744)
Caused by: org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is java.lang.RuntimeException: java.lang.IndexOutOfBoundsException: Index: 4, Size: 0
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:133)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:474)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:688)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:321)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:958)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:947)
at Example.main(Example.java:22)
... 6 more
Caused by: java.lang.RuntimeException: java.lang.IndexOutOfBoundsException: Index: 4, Size: 0
at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:222)
at org.springframework.boot.context.embedded.undertow.UndertowEmbeddedServletContainerFactory.createDeploymentManager(UndertowEmbeddedServletContainerFactory.java:344)
at org.springframework.boot.context.embedded.undertow.UndertowEmbeddedServletContainerFactory.getEmbeddedServletContainer(UndertowEmbeddedServletContainerFactory.java:204)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:157)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:130)
... 13 more
Caused by: java.lang.IndexOutOfBoundsException: Index: 4, Size: 0
at java.util.ArrayList.rangeCheckForAdd(ArrayList.java:643)
at java.util.ArrayList.add(ArrayList.java:455)
at io.undertow.servlet.api.DeploymentInfo.insertFilterServletNameMapping(DeploymentInfo.java:354)
at io.undertow.servlet.spec.ServletContextImpl.addMappingForServletNames(ServletContextImpl.java:836)
at io.undertow.servlet.spec.FilterRegistrationImpl.addMappingForServletNames(FilterRegistrationImpl.java:54)
at org.springframework.boot.context.embedded.FilterRegistrationBean.configure(FilterRegistrationBean.java:287)
at org.springframework.boot.context.embedded.FilterRegistrationBean.onStartup(FilterRegistrationBean.java:256)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.selfInitialize(EmbeddedWebApplicationContext.java:222)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.access$000(EmbeddedWebApplicationContext.java:84)
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext$1.onStartup(EmbeddedWebApplicationContext.java:206)
at org.springframework.boot.context.embedded.undertow.UndertowEmbeddedServletContainerFactory$Initializer.onStartup(UndertowEmbeddedServletContainerFactory.java:517)
at io.undertow.servlet.core.DeploymentManagerImpl.deploy(DeploymentManagerImpl.java:182)
... 17 more