Getting error while following the steps

[ramkis1]

When I run ./mvnw package I get this:

Exception in thread "main" java.lang.reflect.InvocationTargetException
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at org.apache.maven.wrapper.BootstrapMainStarter.start(BootstrapMainStarter.java:39)
        at org.apache.maven.wrapper.WrapperExecutor.execute(WrapperExecutor.java:122)
        at org.apache.maven.wrapper.MavenWrapperMain.main(MavenWrapperMain.java:61)
Caused by: java.lang.NoClassDefFoundError: org/apache/commons/cli/UnrecognizedOptionException
        at java.lang.Class.getDeclaredMethods0(Native Method)
        at java.lang.Class.privateGetDeclaredMethods(Class.java:2701)
        at java.lang.Class.privateGetMethodRecursive(Class.java:3048)
        at java.lang.Class.getMethod0(Class.java:3018)
        at java.lang.Class.getMethod(Class.java:1784)
        at org.codehaus.plexus.classworlds.launcher.Launcher.getEnhancedMainMethod(Launcher.java:168)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:261)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:225)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:347)
        ... 7 more
Caused by: java.lang.ClassNotFoundException: org.apache.commons.cli.UnrecognizedOptionException
        at org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
        at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
        ... 17 more

[dsyer]

Looks like you got a bad jar in your local Maven cache or something. It's nothing to do with the code here anyway, I expect. Try clearing the cache and starting again. Or build in a container.