These are not real errors, but Maven interprets the output of a Java class used to search for widgetsets as errors.
There is a ticket about this, but unfortunately resolving it in the trivial way would break other systems - especially some features of the Vaadin Eclipse plugin. Therefore, all these aspects need to be addressed together and compatibility impacts must be minimized.
After deploying on liferay jboss, I got the following error on the web
Widgetset does not contain implementation for org.tepi.filtertable.FilterTable. Check its @ClientWidget mapping, widgetsets GWT module description file and re-compile your widgetset. In case you have downloaded a vaadin add-on package, you might want to refer to add-on instructions. Unrendered UIDL:
-Unrendered UIDL
Caused by: java.lang.NoClassDefFoundError: com/google/gwt/user/client/ui/HasWidgets
at java.lang.ClassLoader.defineClass1(Native Method) [rt.jar:1.7.0_05]
at java.lang.ClassLoader.defineClass(ClassLoader.java:791) [rt.jar:1.7.0_05]
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) [rt.jar:1.7.0_05]
at org.jboss.modules.ModuleClassLoader.doDefineOrLoadClass(ModuleClassLoader.java:327) [jboss-modules.jar:1.1.1.GA]
at org.jboss.modules.ModuleClassLoader.defineClass(ModuleClassLoader.java:391) [jboss-modules.jar:1.1.1.GA]
... 184 more
Caused by: java.lang.ClassNotFoundException: com.google.gwt.user.client.ui.HasWidgets from [Module “deployment.xxx-portlet.war:main” from Service Module Loader]
at org.jboss.modules.ModuleClassLoader.findClass(ModuleClassLoader.java:190) [jboss-modules.jar:1.1.1.GA]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassUnchecked(ConcurrentClassLoader.java:468) [jboss-modules.jar:1.1.1.GA]
at org.jboss.modules.ConcurrentClassLoader.performLoadClassChecked(ConcurrentClassLoader.java:456) [jboss-modules.jar:1.1.1.GA]
at org.jboss.modules.ConcurrentClassLoader.performLoadClass(ConcurrentClassLoader.java:398) [jboss-modules.jar:1.1.1.GA]
at org.jboss.modules.ConcurrentClassLoader.loadClass(ConcurrentClassLoader.java:120) [jboss-modules.jar:1.1.1.GA]
... 189 more