Migrate to target specifier supported by release flag in newer JDKs

[pzygielo]

This would allow to use mojo.java.target directly to configure maven.compiler.release.

[slawekjaranowski]

ups:

Error:  Rule 4: org.apache.maven.plugins.enforcer.RequireJavaVersion failed with message:
Detected JDK Version: 1.8.0-352 is not in the allowed range 8.

Looks like issue/bug in enforcer-maven-plugin

[pzygielo]

I'm going push change to minimalJavaBuildVersion and add some comment here after that.

[pzygielo]

I guess there is only documentation purpose of requireJavaVersion used here.

With JDK 1.7 I'm getting:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:3.1.0:enforce (mojo-enforcer-rules) on project mojo-parent: Execution mojo-enforcer-rules of goal org.apache.maven.plugins:maven-enforcer-plugin:3.1.0:enforce failed: Unable to load the mojo 'enforce' in the plugin 'org.apache.maven.plugins:maven-enforcer-plugin:3.1.0' due to an API incompatibility: org.codehaus.plexus.component.repository.exception.ComponentLookupException: org/apache/maven/plugins/enforcer/EnforceMojo : Unsupported major.minor version 52.0
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.apache.maven.plugins:maven-enforcer-plugin:3.1.0
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy

anyway.

[slawekjaranowski]

I guess there is only documentation purpose of requireJavaVersion used here.

With JDK 1.7 I'm getting:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-enforcer-plugin:3.1.0:enforce (mojo-enforcer-rules) on project mojo-parent: Execution mojo-enforcer-rules of goal org.apache.maven.plugins:maven-enforcer-plugin:3.1.0:enforce failed: Unable to load the mojo 'enforce' in the plugin 'org.apache.maven.plugins:maven-enforcer-plugin:3.1.0' due to an API incompatibility: org.codehaus.plexus.component.repository.exception.ComponentLookupException: org/apache/maven/plugins/enforcer/EnforceMojo : Unsupported major.minor version 52.0
[ERROR] -----------------------------------------------------
[ERROR] realm =    plugin>org.apache.maven.plugins:maven-enforcer-plugin:3.1.0
[ERROR] strategy = org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy

anyway.

No way for 1.7

[slawekjaranowski]

It a little will complicate when project set target as 8 also want to check if used JDK is ok.
In such case we will must remember to set another property also.

My proposition is to postpone this, and allow 8 as 1.8 for maven enforcer.

[slawekjaranowski]

https://issues.apache.org/jira/browse/MENFORCER-440

[slawekjaranowski]

enforcer released and upgraded here, we can continue with it

[pzygielo]

No way for 1.7

I don't understand.
I think I've said the same.

My question is - what's the point of requiring Java Version with enforcer to be at least 1.8 when that condition can't be validated with earlier JDK?

That's what bothers me: JDK at least 8 is (currently) enforced by the m-enforcer-p anyway in not very friendly manner, without the rule itself.

[slawekjaranowski]

My question is - what's the point of requiring Java Version with enforcer to be at least 1.8 when that condition can't be validated with earlier JDK?

That's what bothers me: JDK at least 8 is (currently) enforced by the m-enforcer-p anyway in not very friendly manner, without the rule itself.

Similar:
https://issues.apache.org/jira/browse/MNG-7566

Currently plugin minimum JDK is not verified ... it cause a error in runtime.

Most of maven core plugins requires 1.8 today, Maven from 3.9 also will required 1.8

By the way, interesting discussion how to inform users of minimum JDK, when user try to execute Maven build with not supported JDK.

[slawekjaranowski]

Suppressed by #359
@pzygielo thanks for idea