s new in Maven 3 - Jazoon

Maven 3.0What’s new in

by Matthew McCullough, Ambient Ideas, LLC

Wednesday, June 2, 2010

In the beginner’s mind there aremany 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


TheRoadmap



3.0


Compatibility!Tested against 100s of Maven 2 projects!Legacy simulation layers!Using for 6 months almost exclusively

!450+ integration tests





603!


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


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

Code


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/release-notes-3.0.x.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


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


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 will be allowed (not quite ready)

!Will require <relativePath> tag


<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> <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


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 2009http\://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


#Maven 2.x#Will run the newest SNAPSHOT, if one is cached locallymvn 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.xmvn archetype:generate#...actually running

mvn org.apache.maven.plugins:maven-archetype-plugin:2.0:generate

Command Line


Core Changes: Plugins!Plugins versions cannot be specified as RELEASE or LATEST

!Affects pom.xml configuration and command line fully-qualified invocation


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

pom.xml


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

pom.xml


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


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


toolchainWednesday, June 2, 2010

What is toolchain?

!Single configuration for multiple plugins!Primarily supports JDK selection today!Extensible for other tools in the future


Toolchain Config

!User tool definitions in file~/.m2/toolchains.xml

!Maven 3.0 command-line path specification!-t <toolchainspath>!--toolchains <toolchainspath>


<?xml version="1.0" encoding="UTF8"?><toolchains> <toolchain> <type>jdk</type> <provides> <version>1.5</version> <vendor>apple</vendor> <id>default</id> </provides> <configuration> <jdkHome>/System/Library/Frameworks/JavaVM.framework/Versions/1.5</jdkHome> </configuration> </toolchain> <toolchain> <type>jdk</type> <provides> <version>1.6</version> <vendor>apple</vendor> <id>onesixjdk</id> </provides> <configuration> <jdkHome>/System/Library/Frameworks/JavaVM.framework/Versions/1.6</jdkHome> </configuration> </toolchain></toolchains>

toolchains.xml


Using Toolchain

!Implemented as a Maven plugin!Add to <plugins> in pom.xml

!Plugin <configuration> specifies a toolchain to use!Toolchain specified by vendor and version


...<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-toolchains-plugin</artifactId> <version>1.0</version> <executions> <execution> <phase>validate</phase> <goals> <goal>toolchain</goal> </goals> </execution> </executions> <configuration> <toolchains> <jdk> <version>1.5</version> <vendor>apple</vendor> </jdk> </toolchains> </configuration></plugin>...

pom.xml


How does it work?

!Toolchain-enabled plugins read toolchain config first

!Plugins fall back to traditional per-plugin config if toolchain config not found


Benefits

!Minimizes plugin configuration!Separates JDK selection from Maven core


mvnshellWednesday, June 2, 2010

http://shell.sonatype.org/




What is mvnshell?

!High performance console!Maven 3.x add-on



Speed of Builds


Performance of Shell

!220% faster in the demo!No JVM warm-up time!Strategies for caching



polyglotWednesday, June 2, 2010

http://polyglot.sonatype.org/


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


<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>

pom.xml



pom.xml


modelVersion: 4.0.0 artifactId: sample-dependencygroupId: com.ambientideasname: Sample Project - One Dependencypackaging: jarurl: 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.yaml


(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.clj


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.scala


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' } }}

pom.groovy


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

!No freeform scripting (yet)


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') }}

pom.groovy with macros


Where did we start from again?



pom.xml


M2EclipseWednesday, June 2, 2010


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!3.5.1 !(Recommended)

!3.6!! ! (Beta)


Dependencies

! Visualizes conflicts! Graph and text form

! Dependency resolution tree! Answers “where is X being brought in from?”


Dependencies

! Easy exclusions! Uses Eclipse refactoring engine



Class Search

! Search the entire central repository for! Artifact

! Package

! Classname

! Lucene database! Incremental updates


Class Search



Maven 3.1Wednesday, June 2, 2010

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>

!“Mixins” for direct dependencies!Sometimes desired over POM inheritance

!Plugin security manager!settings.xml as default implementation


SummaryWednesday, June 2, 2010

Summary•Validations

•Performance

•Compatibility

•Toolchain

•Shell

•Polyglot

•M2Eclipse


Maven 3.0What’s new in

EmailTwitterBlog

Matthew [email protected]@matthewmccullhttp://ambientideas.com/blog


ReferencesWednesday, June 2, 2010

!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


http://svn.apache.org/viewvc/maven/maven-3/trunk

http://svn.apache.org/viewvc/maven/maven-3/trunk

!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


https://svn.apache.org/repos/asf/maven/plugins/branches/maven-site-plugin-3.x/




!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


http://m2eclipse.sonatype.org/sites/m2e

http://m2eclipse.sonatype.org/sites/m2e

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s new in Maven 3 - Jazoon