warnings when using JDK9

[karussell]

There are problems for the build:

[java] WARNING: An illegal reflective access operation has occurred
[java] WARNING: Illegal reflective access by org.dom4j.io.SAXContentHandler (file:/home/travis/.m2/repository/dom4j/dom4j/1.6.1/dom4j-1.6.1.jar) to method com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser$LocatorProxy.getEncoding()
[java] WARNING: Please consider reporting this to the maintainers of org.dom4j.io.SAXContentHandler

but there are also problems for GH itself:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.google.inject.internal.cglib.core.$ReflectUtils$1 (file:/home/travis/.m2/repository/com/google/inject/guice/4.1.0/guice-4.1.0.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Please consider reporting this to the maintainers of com.google.inject.internal.cglib.core.$ReflectUtils$1
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

The issue is known to the guice people: google/guice#1133 as we don't use guice in dropwizard this should be fixed with #1314.

[karussell]

This is fixed due to dropwizardification but for maven shade we get this:

[WARNING] jaxws-api-2.3.0.jar, javax.xml.soap-api-1.4.0.jar, jaxb-api-2.3.0.jar define 1 overlappping classes: 
[WARNING]   - module-info
[WARNING] maven-shade-plugin has detected that some .class files
[WARNING] are present in two or more JARs. When this happens, only
[WARNING] one single version of the class is copied in the uberjar.
[WARNING] Usually this is not harmful and you can skeep these
[WARNING] warnings, otherwise try to manually exclude artifacts
[WARNING] based on mvn dependency:tree -Ddetail=true and the above
[WARNING] output
[WARNING] See http://docs.codehaus.org/display/MAVENUSER/Shade+Plugin

[karussell]

Upgrading to more recent plugin version removes this but gives:

[WARNING] Discovered module-info.class. Shading will break its strong encapsulation.

which I find acceptable for the web "fat jar" and we need to modularize our project at a later project in a different issue.