It happens because you downloaded project as zip file instead of performing `git clone`.
oxd is using `git-commit-id-plugin` maven plugin. As said in your log output:
[ERROR] Failed to execute goal pl.project13.maven:git-commit-id-plugin:2.1.12:revision (get-the-git-infos) on project oxd-server: .git directory could not be found! Please specify a valid [dotGitDirectory] in your pom.xml -> [Help 1]
We always perform `git clone` which you can do as well to build the project.
Otherwise you can add `<failOnNoGitDirectory>false</failOnNoGitDirectory>` to `git-commit-id-plugin`, so it will ignore `.git` folder absence and will build project successfully.
Plugin description in `pom.xml` should look as this (on your machine `E:\DATA\Programming\gluu-client\oxd-version_3.1.1\oxd-server\pom.xml`):
I've added this property by default since 3.1.4, so nobody will face same problem for future versions. (Thank you for reporting it !)
`https://github.com/GluuFederation/oxd` is main repo for `oxd-server`, `oxd-https-extension` and `oxd-client`. You can find many tests there which shows how interaction with oxd is performed. However we don't have demo code in this repo. Demo application is located here:
`https://github.com/GluuFederation/oxd-java-sample` with quite verbose explanation.