The document provides an overview of Apache Maven, focusing on its ecosystem, plugin architecture, and recent updates related to version 4.0.0, including changes to the Project Object Model (POM), improvements in reactor enhancements, and plugin API modifications. It details various components, such as plugins, core modules, and consumer POM formats, alongside future developments and requirements for Java versions. The document also addresses enhancements made in Maven 3.9.x and the anticipated features in the upcoming Maven 4 releases.

1. https://linktr.ee/khmarbaise
Email: maven4@soebes.de
Dipl.Ing.(FH) Karl Heinz Marbaise
Apache Maven
Version
4.0.0 – beta X

2. 2
About me
●
Apache Maven Committer
– since Dec. 2013
●
Apache Maven PMC Member
– since August 2014
●
Apache Software Foundation Member
– since April 2017
●
Apache Maven Project Chairman
– Since April 2022

3. 3
Agenda
●
Apache Maven Ecosystem
●
Maven Ecosystem
●
Architecture
●
Consumer/Build POM
●
Reactor Enhancements
●
Improvements / News
●
JDK Requirement

4. 4
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer

5. 5
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• Core: clean, compiler, resources, install,
deploy, surefire, …
• Packaging: jar, war, shade, source, jlink,
jmod, …
• Reporting: site, javadoc, jxr, pmd, jdeps,
checkstyl, ...
• Tools: archetype, assembly, enforcer,
dependency, …

6. 6
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent
POMs
Archetypes
Indexer
• ASF Maven Parent
• Maven Parent
• Maven Plugin Parent
• Maven Shared Parent
• Maven Skins Parent
• Apache Resource Bundle

7. 7
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• maven-archiver
• maven-invoker
• maven-filtering
• maven-dependency-analyzer
• maven-jarsigner
• maven-shared-utils
• maven-shared-io
• ...

8. 8
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• Doxia Core
• Doxia Site Tools
• Doxia Modules
● apt, xdoc, markdown,FML, …
• ...

9. 9
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• Maven Default Skin
• Maven Fluido Skin
• Maven Application Skin
• Maven Classic Skin
• Maven Stylus Skin

10. 10
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• maven-archetype-j2ee-simple
• maven-archetype-plugin
• maven-archetype-quickstart
• ...

11. 11
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
• aka Eclipse Aether (2016)
http://incubator.apache.org/ip-
clearance/maven-aether.html

12. 12
Apache Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer

13. 13
Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
Plexus Components (~13) MojoHaus Plugins (~80)
• https://github.com/codehaus-plexus
https://github.com/codehaus-plexus
● plexus-classworlds
● plexus-modello
● plexus-utils
● plexus-archiver
● plexus-io
● plexus-languages
● Plexus-interpolation
...

14. 14
Maven Ecosystem
Maven Plugins (~50)
Maven
Core Core
ITs
Artifact Resolver
Maven Shared Components (~25)
Doxia
Skins
Parent POMs
Archetypes
Indexer
Plexus Components (~13) MojoHaus Plugins (~80)
• https://github.com/mojohaus/
https://github.com/mojohaus/
● mrm-maven-plugin
● versions-maven-plugin
● build-helper-maven-plugin
● buildnumber-maven-plugin
● animal-sniffer-maven-plugin
● appassembler-maven-plugin
● jaxb2-maven-plugin
● flatten-maven-plugin
● exec-maven-plugin
● rpm-maven-plugin
● templating-maven-plugin
● ...

15. 15
Architecture
Maven 2 - 2005

16. 16
Architecture
Maven 3 - 2010

17. 17
Architecture
Maven 3.5+ - 2017

18. 18
Architecture
Maven 4.X - 2020-2024

19. 19
Consumer / Build POM
POM V4
●
Maven 1 started with the story
modelVersion 3.0.0
●
Maven 2/3 has continued the story with
modelVersion 4.0.0
<project ...>
<modelVersion>4.0.0</modelVersion>
…
</project>

20. 20
Consumer / Build POM
POM V4
●
The pom declarares the following
information:
●
dependencies, dependencyManagement
●
plugins, pluginManagement
●
profiles, repositories
●
build, reporting
●
distributionManagement
●
etc.

21. 21
Consumer / Build POM
POM V4
●
The function of a POM:
1.Serves as declarative description of
the build process for a project.
2.Serves as a description of the project
dependency graph.

22. 22
Consumer / Build POM
POM V4
●
Changing the POM format?
– The POM is consumed by:
●
Apache BuildR, Gradle, Apache Ivy, sbt
●
by IDE's
●
and many other tools
– as a description of dependencies.

23. 23
Consumer / Build POM
POM V4
●
Requirements to change the POM
format:
– All tools would needed to be changed.
– We have to fork
fork Central Repository.

24. 24
Consumer / Build POM
POM V4
●
Requirements to change the POM
format:
– All tools would needed to be changed.
– We have to fork
fork Central Repository.

25. 25
Consumer / Build POM
POM V4+
Build
Information
POM V4+ POM V4
Consumer POM
Central Repository
Build POM
Project Dependency Tree (PDT)

26. 26
Consumer / Build POM
POM V4
●
POM V4 a.k.a. Consumer POM
Consumer POM
– Contains only dependencies (+
dependencyManagement)
– Remove all properties / build / modules
/ parent / ….
– See flatten-maven-plugin
●
https://cwiki.apache.org/confluence/display/MAVEN/Build+vs+Consumer+POM

27. 28
POM V4+ → Maven 4.X
●
Core must be able to read:
– POM V4
– POM V4+
●
Core must be able to produce POM V4
●
https://cwiki.apache.org/confluence/display/MAVEN/Build+vs+Consumer+POM

28. 29
Improvements / News
●
Maven 3.9.X (3.9.0...3.9.9 in 2024)
– Bug fixing and improvements
– Moved away from Wagon to Maven
Resolver (aka native HTTP).
– Plugin API changes with some hints as
preparation for Maven 4.X
You might have seen some of them!
●
„-Dmaven.plugin.validation=verbose“
●
https://maven.apache.org/docs/history.html
●
https://maven.apache.org/guides/mini/guide-resolver-transport.html

29. 30
Improvements / News
●
Maven 3.9.X (3.9.0...3.9.9 in 2024)
– Since Maven 2 ancient version of
plexus-utils was injected. Not done
anymore (might break something!).
– No bootstrap of RepositorySystem (via
deprecated ServiceLocator!)
– Support for „mvn
pluginPrefix:version:goal” invocation
https://maven.apache.org/docs/history.html

30. 31
Improvements / News
●
Maven 3.9.X (3.9.0...3.9.9 in 2024)
– Removed some deps for example
commons-lang (some kind of diet ;-))
https://maven.apache.org/docs/history.html

31. 32
Improvements / News
●
Maven 3.9.2+
– Use the Force Luke:
– Create an „.mvn“ directory.
– New properties (only from
.mvn/maven.config or CL):
●
session.topDirectory – reactor top
●
session.rootDirectory – project root
(where „.mvn“ required!).
https://maven.apache.org/docs/3.9.2/release-notes.html

32. 33
Improvements / News
●
Maven 4 – 4.0.0-alpha-7 (Jun 2023)
– Build/Consumer POM
– A lot of reactor improvements
– Plugin API Changes
●
Some of them are breaking changes!
See 3.9.X
– Identifiy root location of multi module
build („.mvn/“ or POM configuration).
https://cwiki.apache.org/confluence/display/MAVEN/Build+vs+Consumer+POM

33. 34
Improvements / News
●
Maven 4 – 4.0.0-alpha-8 (20. Oct 2023)
– Switch to Woodstox XML
– Introduce Model Version 4.1.0
●
„root“ element in version 4.1.0
– Glob Pattern for exclusions
<excludes>
<exclude>
<groupId>com.jdom.*</groupId>
<artifactId>*</artifactId>
</exclude>
</excludes>

34. 35
Improvements / News
●
Maven 4 – 4.0.0-alpha-8 (20. Oct 2023)
– „BOM“ Packaging, Trim down
consumer POM
– Core Extension in .m2
– Alternate POM Syntax possible
●
MNG-7836
https://maven.apache.org/docs/4.0.0-alpha-8/release-notes.html

35. 36
Improvements / News
●
Maven 4 – 4.0.0-alpha-8 (20. Oct 2023)
– POM Goal Ordering (MNG-7804,
Model 4.1.0):
<execution>
<id>400. This should be fourth</id>
<goals>
<goal>run</goal>
</goals>
<phase>clean</phase>
<priority>400</priority>
</execution>

36. 37
Improvements / News
●
Maven 4 – 4.0.0-alpha-8 (20. Oct 2023)
– Support configuration in
extensions.xml (MNG-7891) (basic).
– support for exclusions when importing
BOMs

37. 38
Improvements / News
●
Maven 4 – 4.0.0-alpha-10 (11.Dec 2023)
– Fixed broken javadoc:jar
– Resolver fixes.
https://maven.apache.org/docs/4.0.0-alpha-10/release-notes.html

38. 39
Improvements / News
●
Maven 4 – 4.0.0-alpha-12 (12.Jan 2024)
– Resolver 2.0.0-alpha-6
– Collection filtering
– Resolvers transitive dependency
manager.
– No resolving of projects outside the
reactor.
https://maven.apache.org/docs/4.0.0-alpha-12/release-notes.html

39. 40
Improvements / News
●
Maven 4 – 4.0.0-alpha-13 (6. Mar 2024)
– JDK 17+
– Resolver 2.0.0-alpha-8.
– WARN on BOM import in the same
reactor.
– Profile activation based on packaging.
– Conflict deps vs. depMgmt. (WARN!)

40. 41
Improvements / News
●
Maven 4 – 4.0.0-beta-3 (22. May 2024)
– Control path where each dep can be
placed; module-path, classpath, doclet
●
<type>jar</type>
– CLASSES and MODULES.
●
<type>modular-jar</type>
– MODULES only.
●
<type>classpath-jar</type>
– CLASSES only.

41. 42
Improvements / News
●
Maven 4 – 4.0.0-beta-3 (22. May 2024)
– <type>fatjar</type>
●
self contained jar; stops resolving
dependencies
– Same repo Id’s settings.xml vs.
pom.xml not detected.

42. 43
Improvements / News
●
Maven 4 – 4.0.0-beta-4 (02. Sept 2024)
– New Phases: before:X, after:X
●
(before:|after:)$phase([$priority])
– For example:
●
before:package, before:integration-test
after:integration-test, after:package,
before:all, after:all etc.
https://cwiki.apache.org/confluence/display/MAVEN/Dynamic+phases

43. 44
Improvements / News
●
Basic Idea to have only:
– A Life Cycle phase for example:
●
clean
– And there is a „before:clean“ and
„after:clean“.
– Instead of „pre-clean“, „post-clean“..

44. 45
Improvements / News
Current Tranisational Future
pre-clean deprecated before:clean
clean clean
post-clean deprecated after:clean

45. 46
Improvements / News
Current Tranisational Future
generate-sources deprecated before:sources
????? sources
process-sources deprecated after:sources
generate-resources deprecated before:resources
????? resources
process-resources deprecated after:resources
????? before:compile
compile compile
process-classes deprecated after:compile

46. 47
Improvements / News
Current Tranisational Future
generate-test-sources deprecated before:test-sources
????? test-sources
process-test-sources deprecated after:test-sources
generate-test-resources deprecated before:test-resources
????? test-resources
process-test-resources deprecated after:test-resources
????? before:test-compile
test-compile test-compile
process-test-classes deprecated after:test-compile

47. 48
Improvements / News
Current Tranisational Future
????? deprecated before:test
test test
????? after:test
prepare-package deprecated before:package
package package
????? after:package

48. 49
Improvements / News
Current Tranisational Future
pre-integration-test deprecated before:integration-test
integration-test integration-test
post-integration-test deprecated after:integration-test

49. 50
Improvements / News
Current Tranisational Future
before:verify
verify verify
after:verify
before:install
install install
after:install
before:deploy
deploy deploy
after:deploy

50. 51
Improvements / News
Current Tranisational Future
pre-site deprecated before:site
site site
post-site deprecated after:site
before:site-deploy
site-deploy site-deploy
after:site-deploy

51. 52
Improvements / News
●
Maven 4 – 4.0.0-beta-4 (02. Sept 2024)
– Model Version 4.1.0
●
Deprecated „<modules>..</modules>“
also the term „multi module project“
●
So now we have „multi-project“ setup.
●
Use
„<subprojects><subproject>..</subpr
oject></subprojects>“ instead.

52. 53
Current working….
●
Maven 4 – 4.0.0-beta-5 (????)
– New CLI component for reuse (for
example in mvnd
– New CLI for password management
– Interpolation Service API
– …

53. 54
Minimum JDK Runtime
Requirements
●
...
●
JDK 6: Maven 3.2.X...3.2.5
●
JDK 7: Maven 3.3.X…3.8.8
●
JDK 8: Maven 3.9.0...3.9.8
●
JDK 8: ….Maven 4.0.0-alpha-12 (BT: 11)
●
JDK 17: Maven 4.0.0-alpha-13….
https://maven.apache.org/docs/history.html

54. 55
Minimum JDK Runtime
Requirements
●
Maven 4.0.0-alpha-13+ (12. March
2024)
– Runtime requirement: JDK 17+
– Buildtime requirement: JDK17+
https://lists.apache.org/thread/bfkvvjftrxypp06yj8zj919fcz0dt2zt

55. 56
Maven 4.0.0+ - Plugins
●
The following plugins:
●
maven-clean-plugin
●
maven-compiler-plugin
●
maven-deploy-plugin
●
maven-install-plugin
●
maven-jar-plugin
●
maven-resources-plugin
●
Maven-source-plugin
– Version 4.0.0-beta-1 (Maven 4 only!)

56. 57
Performance
●
Maven Cache Extension
– Incremental builds works on the modified part of the
project graph part only
– Subtree support for multimodule projects to work on
the part of the codebase in isolation
– Version normalization to support project version
agnostic caches
– Project state restoration (partial) to avoid expensive
tasks (code generation and similar)
https://maven.apache.org/extensions/maven-build-cache-extension/

57. 58
Thank you!
Questions?
https://linktr.ee/khmarbaise