Enforces source compatibility with animal-sniffer

[codefromthecrypt]

Before, finding source compatibility issues relied on building with an
old JDK. This uses animal-sniffer to enforce java language level 6 for
libraries and 7 for executables.

closes #344

[codefromthecrypt]

cc @rspieldenner

[cloudbees-pull-request-builder]

NetflixOSS » denominator » denominator-pull-requests #89 SUCCESS
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[codefromthecrypt]

tested by adding a use of Collections.emptyIterator(), added in Java language level 7, to MockProvider.java. Animal sniffer failed.

:denominator-core:animalSniffer FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':denominator-core:animalSniffer'.
> Signature errors found. Verify them and ignore them with the proper annotation if needed.

[codefromthecrypt]

@alkemist @quidryan any pointers on how to de-boilerplate this? I wasn't able to unwind the desired behavior in the base subprojects block.

[rspieldenner]

in build.gradle at top level

// this goes above plugins block
buildscript {
  repositories { jcenter() }
  dependencies {
    classpath 'be.insaneprogramming.gradle:animalsniffer-gradle-plugin:1.4.0'
  }
}

subprojects {
  // ...
  apply plugin: 'be.insaneprogramming.gradle.animalsniffer'

  animalsniffer {
    signature = "org.codehaus.mojo.signature:java16:+@signature"
  }
}

configure the one that needs 1.7 in that one subprojects and you probably want to keep the sourceCompatibility = 1.6 since it will also set the jdk generated to jdk6 compatible bytecode otherwise gradle defaults you to the jdk it is running in (and the netflixoss plugin will default it to java 1.7 if nothing else is set)

The plugins block imports and applies plugins so it is good in some use cases and not others

[codefromthecrypt]

Thanks for the instructions. Will give it a go!

[cloudbees-pull-request-builder]

NetflixOSS » denominator » denominator-pull-requests #90 SUCCESS
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[cloudbees-pull-request-builder]

NetflixOSS » denominator » denominator-pull-requests #91 SUCCESS
This pull request looks good

[ldaley]

Beaten to the punch by @rspieldenner .

[codefromthecrypt]

Yes. His punches are fast!