Upgrade Xtext to 2.17 for full Java 11 support

[wborn]

This is a PR to upgrade Xtext to 2.17 (#646). The PR already builds successfully on Java 8 and on Java 11 it now builds 105/127 projects. :-)

I haven't tested the end result yet but maybe you can see if all the upgraded dependencies/features make some sense @maggu2810 / @kaikreuzer?

The Java 11 build now fails with:

[ERROR] Failed to execute goal org.reficio:p2-maven-plugin:1.2.0:site (default-cli) on project org.openhab.core.features.p2.repo: Execution default-cli of goal org.reficio:p2-maven-plugin:1.2.0:site failed: org.apache.maven.plugin.MojoExecutionException: Unable to execute mojo: P2 publisher return code was 13 -> [Help 1]

Fixes #646

[wborn]

Upgrading the p2-maven-plugin to 1.3.0 fixed that new Java 11 error. There seem to be some tests failing on Java 11 now. It looks precision related:

TEST serializationTestZoned[16](org.eclipse.smarthome.core.library.types.DateTimeTypeTest) <<< ERROR: expected:<2019-03-13T23:13:15.976658Z> but was:<2019-03-13T23:13:15.976Z>
java.lang.AssertionError: expected:<2019-03-13T23:13:15.976658Z> but was:<2019-03-13T23:13:15.976Z>

---

When building openhab2-addons using a local build of openhab-core and this PR there's an error where the build cannot find the new artifacts:

[INFO] Fetching p2.index from https://dl.bintray.com/openhab/p2/openhab-deps-repo/1.0.40/ (172B)
[INFO] Fetching p2.index from https://dl.bintray.com/openhab/p2/openhab-deps-repo/1.0.40/ (172B)
[INFO] Adding repository https://dl.bintray.com/openhab/p2/openhab-deps-repo/1.0.40

...

[INFO] Resolving dependencies of MavenProject: org.openhab.binding:org.openhab.binding.plclogo:2.5.0-SNAPSHOT @ /home/wouter/git/openhab/openhab2-addons/addons/binding/org.openhab.binding.plclogo/pom.xml
[INFO] {osgi.os=linux, osgi.ws=gtk, org.eclipse.update.install.features=true, osgi.arch=x86}
[ERROR] Cannot resolve project dependencies:
[ERROR]   Software being installed: org.openhab.binding.plclogo 2.5.0.qualifier
[ERROR]   Missing requirement: org.openhab.core.model.item 2.5.0.201903132304 requires 'osgi.bundle; org.eclipse.xtext.xbase.lib 2.17.0' but it could not be found
[ERROR]   Cannot satisfy dependency: org.openhab.binding.plclogo 2.5.0.qualifier depends on: java.package; org.eclipse.smarthome.model.script.actions 0.0.0
[ERROR]   Cannot satisfy dependency: org.openhab.core.model.script 2.5.0.201903132303 depends on: osgi.bundle; org.openhab.core.model.item 0.0.0
[ERROR] 
[ERROR] See http://wiki.eclipse.org/Tycho/Dependency_Resolution_Troubleshooting for help.
[ERROR] Cannot resolve dependencies of MavenProject: org.openhab.binding:org.openhab.binding.plclogo:2.5.0-SNAPSHOT @ /home/wouter/git/openhab/openhab2-addons/addons/binding/org.openhab.binding.plclogo/pom.xml: See log for details -> [Help 1]

That is to be expected I think because they need to be added to a new openhab-deps-repo version? Is there an easy way to workaround this and test if all works well?

[maggu2810]

You could use the runtime BOM as a dependency then everything should be able to resolved by the POM considered dependencies. But it will slow down the whole build.

[wborn]

I managed to get my own p2 repo using Eclipse 2019-03 deployed which I could use for creating a working distro. The distro started and the demo didn't show any issues. :-)

For creating the p2 repo the changes in openhab/openhab-deps-repo#12 are required.

The bundle list reported by Karaf is available in this bundle-list.txt.

[maggu2810]

LGTM.

[maggu2810]

Will merge as soon as @kaikreuzer informs us that ohdr 1.0.41 is published.

I assume I can wait for a notification that the respective pull request you created is merged.
Is it enough to wait for a new build of https://ci.openhab.org/job/openHAB-Deps-Repo?

[wborn]

That's right! I studied how it all works for creating my own P2 repo. ;-) As a sanity check you can also check that the new version is available at the OH P2 bintray repo.

[kaikreuzer]

It has automatically been published by running https://ci.openhab.org/job/openHAB-Deps-Repo/48/.