Java version 11.0.8
Exception in thread "main" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at io.undertow.examples.Runner.main(Runner.java:129)
Caused by: java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:566)
at io.undertow.examples.Runner.main(Runner.java:126)
Caused by: java.lang.NumberFormatException: For input string: "."
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.base/java.lang.Integer.parseInt(Integer.java:638)
at java.base/java.lang.Integer.parseInt(Integer.java:770)
at io.undertow.examples.http2.Http2Server.main(Http2Server.java:68)

https://github.com/undertow-io/undertow/blob/master/examples/src/main/java/io/undertow/examples/http2/Http2Server.java#L68