Maven 3.0 at Øredev

Wha t’s new in Maven 3.0by Matthew McCullough, Ambient Ideas, LLC

In the beginner’s mind there are many possibilities. In the expert’s mind there are few.

This Talk

Maven and You ❖Who will enjoy this talk? ❖Current Maven user ❖Familiar with POM syntax ❖Interested in preparing for Maven 3.0 ❖Comfortable with betas

Maven and Me ❖ Tenure ❖ Using it for 8 years since 0.7 ❖ Contributing to the codebase via patches ❖ Authoring archetypes ❖ 30 open source how-to projects

Maven and Me ❖ Tenure ❖ Using it for 8 years since 0.7 ❖ Contributing to the codebase via patches ❖ Authoring archetypes ❖ 30 open source how-to projects ❖ Mentoring ❖ 3 virtual Sonatype classes a month ❖ Several on-site classes around the globe per year ❖ 30+ global conference and user group talks to date ❖ 50+ enterprise Maven-consulting clients

Maven and Me ❖ Tenure ❖ Using it for 8 years since 0.7 ❖ Contributing to the codebase via patches ❖ Authoring archetypes ❖ 30 open source how-to projects ❖ Mentoring ❖ 3 virtual Sonatype classes a month ❖ Several on-site classes around the globe per year ❖ 30+ global conference and user group talks to date ❖ 50+ enterprise Maven-consulting clients ❖ Writing ❖ O’Reilly: Maven The Deﬁnitive Guide by Tim O’Brien ❖ Promotional materials, testimonial on the back cover ❖ DZone Maven RefCard ❖ 8th most-downloaded card of all time

The Roadmap

Compatibility ❖Tested against 100s of Maven 2 projects ❖Legacy simulation layers ❖Using for 6 months almost exclusively ❖450+ integration tests

Speed ❖ Performance tuned ❖ Benchmarks ❖ Disk I/O ❖ Network I/O ❖ CPU ❖ Memory

Maven Speed Test

Quick ❖ Faster execution ❖ 10% faster in the demo ❖ Multi-threaded downloads ❖ Parallel plugin execution ❖ Java 5 optimized builds

Efficient ❖ Memory conservative ❖ 73% less in the demo ❖ Tuned data structures

Code ❖Largely re-written for quality, ﬂexibility ❖30% smaller code base ❖Continuous integration running test suite

Extensibility ❖Layers of abstraction ❖Plugin classloader partitioning ❖Plexus to Guice IOC rewrite ❖Fully embeddable ❖Basis for derived tools

How can you keep up with Maven 3?

http://maven.apache.org/docs/3.0/release-notes.html

http://delicious.com/matthew.mccullough/maven

POMs & Maven 3.0

POM XML Syntax ❖ No POM syntax changes for Maven 3.0 <project> <modelVersion>4.0.0</modelVersion> <groupId>com.ambientideas</groupId> <artifactId>sample-barestbones</artifactId> <version>1.0-SNAPSHOT</version> </project>

POM XML Validations ❖ Heavily validated against common mistakes ❖ Forward-test with Maven 3.0 ❖Switch back to 2.x for production ❖ 3.0 POMs run better on 2.x

POM XML Validations ❖ Warns when plugin versions are not speciﬁed

“Plugin version omitted” warning

POM XML Validations ❖ Blocks duplicate dependencies ❖Examined in same POM only ❖Conﬂict resolution used otherwise <dependency> <artifactId>junit</modelVersion> <groupId>junit</groupId> <version>3.8.1</version> </dependency> ... <dependency> <artifactId>junit</modelVersion> <groupId>junit</groupId> <version>3.8.2</version> </dependency>

“Duplicate dependency” error

Help URLs ❖ Wiki page URLs now shown for all error messages

Parent POM References ❖ Parent POMs now prefer to resolve from repositories ❖ Better consistency on multi-module builds ❖ Version-less parent references may be allowed (not ready yet) ❖ Will require <relativePath> tag ❖ MNG-624

<project> <modelVersion>4.0.0</modelVersion> <parent> <groupId>com.ambientideas</groupId> <artifactId>sample-multimodulejava-parent</artifactId> <version>1.0-SNAPSHOT</version> </parent> </project>

<project> <modelVersion>4.0.0</modelVersion> <parent> <groupId>com.ambientideas</groupId> <artifactId>sample-multimodulejava-parent</artifactId> <relativePath>../</relativePath> </parent> </project>

Profiles Consolidated • Profiles.xml external ﬁle support removed • Folded into pom.xml • Already a best-practice • Necessary for Polyglot Maven

Parallel Builds

Parallel Build Approach •Examines reactor build plan •Threads up to what’s possible •Governed by your provided limits

https://cwiki.apache.org/MAVEN/parallel-builds-in-maven-3.html

Parallel Build Syntax •Four threads mvn -T 4 install

Parallel Build Syntax •Two threads per core mvn -T 2C install

Serial Building

Parallel Building

Artifact Behavior Changes

Maven 1.0 Deprecated • Maven 1.0 repository support removed <layout>legacy</layout>

SNAPSHOT Datestamps •Deprecated <uniqueVersion> false </uniqueVersion> •SNAPSHOTs now always deployed with date-stamps

Artifact Resolution Caching • Caches lookups whether found or missing • Stored in: ~/.m2/repo/.../<artifact>.lastUpdated • Sample contents: #Last modified on: Thu Dec 31 10:42:13 MST 2009 #Thu Dec 31 10:42:13 MST 2009 http://localhost:8081/nexus/content/groups/public=12333938 • Overridden by: mvn <phase> -U

Plugin Behavior Changes

Core Changes: Plugins ❖Plugin version auto-selection favors RELEASEs over SNAPSHOTs ❖Affects command-line invocation of plugins

Command Line #Maven 2.x #Will run the newest SNAPSHOT, if one is cached locally mvn archetype:generate #...actually running mvn org.apache.maven.plugins:maven-archetype-plugin:1.0-SNAPSHOT:generate #Maven 3.x #Will always run the newest RELEASE in Maven 3.x mvn archetype:generate #...actually running mvn org.apache.maven.plugins:maven-archetype-plugin:2.0:generate

Core Changes: Plugins ❖Plugins versions cannot be specified as RELEASE or LATEST ❖Affects pom.xml configuration and command line fully-qualified invocation

pom.xml ... <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-toolchains-plugin</artifactId> <version>LATEST</version> </plugin> ...

Core Changes: Plugins ❖Plugins only resolved from <pluginRepository> locations

http://cwiki.apache.org/MAVEN/maven-3x-compatibility-notes.html

Site Plugin ❖ Near-complete rewrite ❖ Separation of <reporting> from core Maven codebase ❖ Preparation for Maven 3.1 pom.xml syntax changes

Not a technical rant on Maven vs. Ant

mvnshell

http://shell.sonatype.org/

What is mvnshell? ❖ High performance console ❖ Maven 3.x add-on

The shell and its commands

Color highlighting

Speed of Builds

Performance of Shell ❖220% faster in the demo ❖No JVM warm-up time ❖Strategies for caching

Subcommands, archetypes

polyglot

http://polyglot.sonatype.org/

What is polyglot Maven? ❖ Maven 3 superset ❖A full distribution of Maven ❖Enabled by Maven 3 embedding ❖Multi-language mvn command

What is polyglot Maven? ❖ POM ﬁle converter ❖translate tool ❖Any-to-Any language translation

pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http:// www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http:// maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.ambientideas</groupId> <artifactId>sample-dependency</artifactId> <packaging>jar</packaging> <version>1.0-SNAPSHOT</version> <name>Sample Project - One Dependency</name> <url>http://github.com/matthewmccullough/maven-training/</url> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> </dependencies> </project>

Translating a POM from XML to YAML

pom.yaml modelVersion: 4.0.0 artifactId: sample-dependency groupId: com.ambientideas name: Sample Project - One Dependency packaging: jar url: http://github.com/matthewmccullough/maven-training/ version: 1.0-SNAPSHOT dependencies: - {artifactId: junit, groupId: junit, optional: false, scope: test, type: jar, version: 3.8.1}

pom.clj (defproject main "com.ambientideas:sample-dependency:1.0-SNAPSHOT" :model-version "4.0.0" :add-default-plugins false :name "Sample Project - One Dependency" :packaging "jar" :url "http://github.com/matthewmccullough/maven-training/" :test-dependencies [["junit:junit:3.8.1"]])

pom.scala project { m => m.artifactId = "sample-dependency" m.dependency { d => d.artifactId = "junit" d.groupId = "junit" d.optional = false d.scope = "test" d._type = "jar" d.version = "3.8.1" } m.groupId = "com.ambientideas" m.modelVersion = "4.0.0" m.name = "Sample Project - One Dependency" m.packaging = "jar" m.url = "http://github.com/matthewmccullough/maven-training/" m.version = "1.0-SNAPSHOT" }

pom.groovy project { modelVersion '4.0.0' groupId 'com.ambientideas' artifactId 'sample-dependency' version '1.0-SNAPSHOT' name 'Sample Project - One Dependency' url 'http://github.com/matthewmccullough/maven-training/' dependencies { dependency { groupId 'junit' artifactId 'junit' version '3.8.1' scope 'test' } } }

Translating a POM and building from it

Polyglot DSLs ❖A true DSL framework ❖ Maven lifecycle hooks ❖Can modify execution plan ❖Supplement the lifecycle

Polyglot Macros ❖Maven-speciﬁc macros ❖Allows for more concise POMs ❖Groovy polyglot showcasing this ❖Freeform scripting in Groovy

pom.groovy with macros project { modelVersion '4.0.0' $artifact('com.ambientideas', 'sample-dependency’, '1.0-SNAPSHOT') name 'Sample Project - One Dependency' url 'http://github.com/matthewmccullough/maven-training/' dependencies { dependency('junit', 'junit’, '3.8.1', ‘test') } }

Where did we start from again?

M2Eclipse

Upgrading M2Eclipse ❖Latest version, 0.10 ❖Code quality improvements ❖Performance increases ❖Packaging changes ❖Two distinct update sites ❖ Core: http://m2eclipse.sonatype.org/sites/m2e ❖ Extensions: http://m2eclipse.sonatype.org/sites/m2e-extras

Eclipse Versions Supported ❖3.4 ❖3.5 ❖3.6

Dependencies ❖ Visualizes conﬂicts ❖ Graph and text form ❖ Dependency resolution tree ❖ Answers “where is X being brought in from?”

Dependency conﬂicts

Dependencies ❖ Easy exclusions ❖ Uses Eclipse refactoring engine

Exclusions

Class Search ❖ Search the entire central repository for ❖ Artifact ❖ Package ❖ Classname ❖ Lucene database ❖ Incremental updates

Class Search

Resources

Free Books http://books.sonatype.com

Examples ❖ Ambient sample projects ❖ http://github.com/matthewmccullough/maven-training ❖ Sonatype sample projects ❖ http://www.sonatype.com/products/maven/ documentation/book-defguide

Maven 3.1

Maven 3.1 POM Changes ❖ Backwards compatibility by modelVersion ❖ Final identiﬁer TBD for 3.1 POM syntax ❖ Allows 3.1 to read 3.0, 2.0 POMs <project> <modelVersion>4.0.0</modelVersion> <groupId>com.ambientideas</groupId> <artifactId>sample-barestbones</artifactId> <version>1.0-SNAPSHOT</version> </project>

Maven 3.1 POM Changes ❖pom.xml syntax changes ❖ Site plugin takes over <reporting>

Maven 3.1 POM Changes ❖“Mixins” for direct dependencies ❖ Sometimes desired over POM inheritance

Maven 3.1 POM Changes ❖Plugin security manager ❖ settings.xml as default implementation

Summary

Summary •Validations •Performance •Compatibility •Toolchain •Shell •Polyglot •M2Eclipse

What ’s new in Maven 3.0 Matthew McCullough Email matthewm@ambientideas.com Twitter @matthewmccull Blog http://ambientideas.com/blog

References

❖Maven 3 Core ❖ Homepage ❖ http://maven.apache.org/ ❖ Source Code ❖ http://svn.apache.org/viewvc/maven/maven-3/trunk ❖ Wiki ❖ http://cwiki.apache.org/MAVEN/maven-3x.html ❖ Bug Tracking ❖ http://jira.codehaus.org/browse/MNG ❖ Compatibility ❖ http://cwiki.apache.org/MAVEN/maven-3x-compatibility-notes.html ❖ Blog Posts ❖ http://www.sonatype.com/people/2009/11/maven-3x-paving-the-desire-lines- part-two/ ❖ Bookmarks ❖ http://delicious.com/matthewmccullough/maven

❖Maven 3 Site Plugin ❖ Source Code ❖ https://svn.apache.org/repos/asf/maven/plugins/branches/ maven-site-plugin-3.x/ ❖ Wiki ❖ http://cwiki.apache.org/MAVEN/maven-3x-and-site-plugin.html

❖Maven Shell ❖ Source Code ❖ http://github.com/sonatype/mvnsh/ ❖ Wiki ❖ https://docs.sonatype.org/display/MVNSH ❖ Homepage ❖ http://shell.sonatype.org/

❖Polyglot Maven ❖ Homepage ❖ http://polyglot.sonatype.org/ ❖ Source Code ❖ http://github.com/sonatype/polyglot-maven ❖ Wiki ❖ https://docs.sonatype.org/display/PMAVEN/ ❖ Groovy Macros ❖ https://docs.sonatype.org/display/PMAVEN/Groovy

❖M2Eclipse ❖ Homepage ❖ http://m2eclipse.sonatype.org/ ❖ Update Sites ❖ http://m2eclipse.sonatype.org/sites/m2e ❖ http://m2eclipse.sonatype.org/sites/m2e-extras

Maven 3.0 at Øredev

by Matthew McCullough on Nov 12, 2010

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Maven 3.0 at Øredev — Presentation Transcript

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