#242 Check Java 9 Compatibility

[Till Schäfer]

With Java 9 on the horizon, we have to check the compatibility of SH with this new release. Java 9 is a bit special because it will include project Jigsaw, the modularization of the java framework. The modularization hides parts of the java framework, that never have been part of the official interfaces, but still were accessible (because java had no mechanism to effectively hide interal classes). In combination with customized swing components and old libraries such as piccolo this might become a problem.

Long story short: We should test SH with the Java 9 developer build available, such that we can react backward compatibility problems early.

[Till Schäfer]

good introduction into the problems, that might occur: http://blog.codefx.org/java/dev/how-java-9-and-project-jigsaw-may-break-your-code/

[Till Schäfer]

More specific links for migration:

"Prepare for JDK 9", Alan Bateman https://www.youtube.com/watch?v=eU8hCCjGSbE
CodeFX, Nicolai Parlog: https://codefx-org.github.io/talk-jigsaw-walkthrough/#/_compatibility

[Till Schäfer]

just some illegal access warnings from starting SH on java 9:

/opt/oracle-jdk-bin-9.0.4/bin/java -jar --illegal-access=warn ~/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/scaffold-hunter-2.6.3-293-g8c97f122.jar
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.util.TreeMap.comparator
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.util.TreeSet.m
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.util.Properties.defaults
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.lang.reflect.Proxy.h
WARNING: Illegal reflective access by com.thoughtworks.xstream.converters.reflection.AbstractAttributedCharacterIteratorAttributeConverter (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to method java.text.AttributedCharacterIterator$Attribute.getName()
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.awt.font.TextAttribute.instanceMap
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.util.EnumSet.elementType
WARNING: Illegal reflective access by com.thoughtworks.xstream.core.util.Fields (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.util.EnumMap.keyType
WARNING: Illegal reflective access by javassist.util.proxy.SecurityActions (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/hibernate/javassist-3.18.1-GA.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Illegal reflective access by javassist.util.proxy.SecurityActions (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/hibernate/javassist-3.18.1-GA.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int,java.security.ProtectionDomain)
WARNING: Illegal reflective access by com.thoughtworks.xstream.converters.reflection.FieldDictionary (file:/home/till/data/programmierung/java/egit_repos/edu.udo.scaffoldhunter/dist/lib/xstream/xstream-1.4.9.jar) to field java.awt.Dimension.serialVersionUID