Geneva Jug (30th March, 2010) - Maven

Apache Maven - GenevaJUG - March 30th, 2010

Arnaud Héritier eXo Platform

Software Factory Manager

Licensed under a Creative Commons license

Arnaud Héritier

●  Committer since 2004 and member of the Project Management Committee

●  Coauthor of « Apache Maven » published by Pearson (in French)

●  http://aheritier.net

●  Software Factory Manager eXo platform -  In charge of tools and

methods


CHOOSE YOUR MENU Apache Maven


Overview ●  Definition ●  History ●  Concepts

-  Conventions -  POM -  Reactor and Modules -  Inheritance -  Artifact Repository -  Dependency -  Version -  Profiles -  Build Lifecycle And Plugins

●  Maven or not Maven, that is the question ! -  Maven, the project choice -  Maven, the corporate choice -  Competitors


Ecosystem ●  Repository Managers ●  Quality Management

-  Tests Automation -  Quality Metrics Reports -  Project Reports -  Sonar

●  Continuous Integration ●  IDE

-  Eclipse -  Idea IntelliJ -  Netbeans


Good & Bad Practices ●  K.I.S.S. ●  Project Organization ●  POM ●  Development


Usecases ●  Secure your credentials ●  Build a part of your project using reactor options ●  Automate your release process

-  (at least the technical part)


Back to the future ●  Maven 2.x ●  Maven 3.x ●  Community


OVERVIEW Apache Maven


Definition ●  Apache Maven is a software project management

and comprehension tool. ●  Based on the concept of a project object model

(POM) -  Maven can manage a project's build, binaries,

reporting and documentation from a central piece of information.


History ●  Initiated in 2001 by Jason Van Zyl in Alexandria, an

Apache Jakarta project, ●  Moved to Turbine few months after, ●  Became a Top Level Project in 2003. ●  Maven 2.0 released in September 2005 ●  Maven 3.0 … coming soon !!!


CONCEPTS Apache Maven

12


Conventions ●  1 project = 1 artifact (pom, jar, war, ear, …)

●  Standardized -  directories layout

●  *.java to compile in src/[main|test]/java

●  *.xml, *.properties needed in classpath and to bundle in archive in src/[main|test]/resources

●  … -  project descriptor (POM) -  build lifecycle

13


POM ●  An XML file (pom.xml)

●  Describing -  Project identification -  Project version -  Project description -  Build settings -  Dependencies -  …

<?xml version="1.0" encoding="UTF-8"?>!

<project>!

<modelVersion>4.0.0</modelVersion>!

<groupId>net.aheritier.samples</groupId>!

<artifactId>simple-webapp</artifactId>!

<version>1.1-SNAPSHOT</version>!

<packaging>war</packaging>!

<name>Simple webapp</name>!

<inceptionYear>2007</inceptionYear>!

<dependencies>!

<dependency>!

<groupId>org.springframework</groupId>!

<artifactId>spring-struts</artifactId>!

<version>2.0.2</version>!

</dependency>!

...!

</dependencies>!

</project>!


Reactor <project>!

...!

<modules>!

<module>moduleA</module>!

<module>moduleB</module>!

<module>moduleC</module>!

<module>moduleD</module>!

<module>moduleE</module> !

<module>moduleF</module>!

</modules>!

...!

</project>!

●  Split your project in sub-modules

●  Maven computes the build order from dependencies between sub-modules.

●  Modules have to be defined in the POM -  No auto-discovery for

performance reasons


Inheritance ●  Share settings between

projects/modules ●  By default the parent

project is supposed to be in the parent directory (../)

<parent>!

<groupId>net.aheritier.sample</groupId>!

<artifactId>my-parent</artifactId>!

<version>1.0.0-SNAPSHOT<version>!

</parent>!


Inheritance

Insert README in all artifacts

Use assembly to package batchs

Use clirr to validate backward compatibility

Use a technical inheritance to organize sub-modules


Artifact Repository ●  By default :

-  A central repository ●  http://repo1.maven.org/

maven2 ●  Several dozen of Gb of OSS

libraries -  A local repository

●  ${user.home}/.m2/repository ●  All artifacts

-  Used by maven and its plugins

-  Used by your projects (dependencies)

-  Produced by your projects


Artifact Repository ●  By default Maven

downloads artifacts required by the project or itself from central

●  Downloaded artifacts are stored in the local repository

●  Used to store : -  Project’s binaries -  Project’s dependencies -  Maven and plug-ins binaries


Without Maven With Maven

Dependencies


Dependencies ●  Declaratives

-  groupId + artifactId + version (+ classifier) -  Type (packaging) : jar, war, pom, ear, …

●  Transitives -  Lib A needs Lib B -  Lib B needs Lib C -  Thus Lib A needs Lib C


Dependencies ●  Scope

-  Compile (by default) : Required to build and run the application

-  Runtime : not required to build the application but needed at runtime

●  Ex : taglibs -  Provided : required to build the application but not

needed at runtime (provided by the container) ●  Ex : Servlet API, Driver SGBD, …

-  Test : required to build and launch tests but not needed by the application itself to build and run

●  Ex : Junit, TestNG, DbUnit, … -  System : local library with absolute path

●  Ex : software products


Dependencies ●  Define all dependencies you are using

-  and no more ! ●  If you have optional dependencies

-  Perhaps you should have optional modules instead ●  Cleanup your dependencies with

-  mvn dependency:analyze!●  Study your dependencies with

-  mvn dependency:tree!-  mvn dependency:list!


Versions ●  Project and dependency versions ●  Two different version variants -  SNAPSHOT version

●  The version number ends with –SNAPSHOT ●  The project is in development ●  Deliveries are changing over the time and are overridden

after each build ●  Artifacts are deployed with a timestamp on remote

repositories -  RELEASE version

●  The version number doesn’t end with –SNAPSHOT ●  Binaries won’t change


Versions


Versions ●  About SNAPSHOT dependencies

-  Maven allows the configuration of an update policy. The update policy defines the recurrence of checks if there is a new SNAPSHOT version available on the remote repository :

●  always ●  daily (by default) ●  interval:X (a given period in minutes) ●  never

-  Must not be used in a released project ●  They can change thus the release also ●  The release plugin will enforce it


Versions

●  Range -  From … to … -  Maven automatically searches for the corresponding

version (using the update policy for released artifacts) -  To use with caution

●  Risk of non reproducibility of the build ●  Risk of side effects on projects depending on yours.


Versions

mvn versions:set –DnewVersion=A.B.C-SNAPSHOT!

●  Use the versions plugin to update all versions of your project and its modules


Profiles

mvn <phases or goals> !

-PprofileId1,-profileId2 !

-P!profileId3!

●  Allow to modify the default behavior of Maven by overriding/adding some settings

●  Use mvn help:active-profiles to debug ●  Explicit activation or deactivation


Profiles

<settings>!

...!

<activeProfiles>!

<activeProfile>profile-1</activeProfile>!

</activeProfiles>!

...!

</settings>!

●  activeByDefault = If no other profile is activated ●  Activation through Maven settings


Profiles

<profiles>!

<profile>!

<activation>!

<property>!

<name>!skip-enforce</name>!

</property>!

</activation>!

...!

</profile>!

</profiles>!

<profiles>!

<profile>!

<activation>!

<property>!

<name>run-its</name>!

<value>true</value>!

</property>!

</activation>!

...!

</profile>!

</profiles>!

●  Activation based on environment variables


Profiles

<profiles>!

<profile>!

<activation>!

<os>!

<name>Windows XP</name>!

<family>Windows</family>!

<arch>x86</arch>!

<version>5.1.2600</version>!

</os>!

</activation>!

...!

</profile>!

</profiles>!

<profiles>!

<profile>!

<activation>!

<jdk>[1.3,1.6)</jdk>!

</activation>!

...!

</profile>!

</profiles>!

●  OS / Java settings


Profiles

<profiles>!

<profile>!

<activation>!

<file>!

<missing>${project.build.directory}/generated-sources/axistools/wsdl2java/</missing>!

</file>!

</activation>!

...!

</profile>!

</profiles>!

●  Activation on present or missing files


Build Lifecycle And Plugins

●  Plugin based architecture for a great extensibility

●  Standardized lifecycle to build all types of archetypes


Build Lifecycle And Plugins Default Lifecycle Clean Lifecycle Site Lifecycle validate pre-clean pre-site

initialize clean site generate-sources post-clean post-site

process-sources site-deploy generate-resources

process-resources

compile process-classes

generate-test-sources

process-test-sources

generate-test-resources

process-test-resources

test-compile

process-test-classes

test prepare-package

package pre-integration-test

integration-test

post-integration-test

verify

install deploy


Build Lifecycle And Plugins ●  Many plugins

-  Packaging -  Reporting -  IDE integration -  Miscellaneous tools integration

●  Many locations -  maven.apache.org -  mojo.codehaus.org -  code.google.com -  …


MAVEN OR NOT MAVEN, THAT IS THE QUESTION !

Apache Maven


Maven, the project’s choice ●  Application’s architecture

-  The project has the freedom to divide the application in modules

-  Maven doesn’t limit the evolution of the application architecture

●  Dependencies management -  Declarative : Maven automatically downloads them and

builds the classpath -  Transitive : We define only what the module needs

itself


Maven, the project’s choice ●  Centralizes and automates

all development facets (build, tests, releases)

●  One thing it cannot do for you : to develop

-  Builds -  Tests -  Packages -  Deploys -  Documents -  Checks and reports about

the quality of developments


Maven, the corporate’s choice ●  Widely adopted and known

-  Many developers ●  Developments are standardized ●  Decrease of costs

-  Reuse of knowledge -  Reuse of configuration fragments -  Reuse of process and code fragments

●  Product quality improvement -  Reports and monitoring


Competitors ●  Ant + Ivy, Easy Ant, Gant, Gradle, Buildr… ●  Script oriented

-  You can do what you want ! ●  Reuse many of Maven conventions (directories

layout, …) and services (repositories) but without enforcing them

●  The risk for them : Not being able to evolve due to the too high level of customization proposed to the user. -  We tried on Maven 1 and it died because of that. It was

impossible to create a set of tests to cover all usages. -  It’s like providing a framework without public API


You can have (if you have good skills)

But often you have (moreover after years …)

With scripts oriented builds


We dream to deliver (Maven 3.x)

But today we have too often (Maven 2.x)

With Maven


ECOSYSTEM Apache Maven


Maven’s ecosytem ●  Maven alone is nothing ●  You can integrate it with many tools

-  A large set of plug-ins is already available -  You can define your own plug-ins


REPOSITORY MANAGERS Apache Maven


Repository Managers ●  Basic services

-  Search artifacts -  Browse repositories -  Proxy external repositories -  Host internal repositories -  Security

●  Several products -  Sonatype Nexus (replaced

Proximity) -  Jfrog Artifactory -  Apache Archiva


Secure your builds ●  Deploy a repository manager to proxy externals

repositories to : -  Avoid external network outages -  Avoid external repository unavailabilities -  To reduce your company’s external network usage -  To increase the speed of artifact downloads

●  Additional services offered by such servers : -  Artifacts procurement to filter what is coming from the

outside -  Staging repository to validate your release before

deploying it


Nexus at eXo for productivity


Nexus at eXo for collaboration ●  Deploy 3rd Party Artifacts ●  Collaborate with Internal

Repositories ●  Distribute to the community

with Public Repositories ●  Distribute to customers

with Private Repositories


Nexus at eXo for quality ●  Ease the Burden on Central and others remote

repositories ●  Gain Predictability and Scalability ●  Control and Audit Dependencies and Releases ●  Stage releases


QUALITY MANAGEMENT Apache Maven


Tests Automation ●  Use automated tests as often as you can ●  Many tools are available through Maven

-  JUnit, TestNG – unit tests, -  Selenium, Canoo – web GUI test, -  Fitnesse, Greenpepper – functional tests, -  SoapUI – web services tests -  JMeter – performances tests -  And many more frameworks are available to reply your

needs


Quality Metrics ●  Extract quality metrics from your project and

monitor them : -  Code style (CheckStyle) -  Bad practices or potential bugs (PMD, FindBugs, Clirr) -  Tests coverage (Cobertura, Emma, Clover) -  …

●  You can use blocking rules -  For example, I break the build if the upward

compatibility of public APIs is broken ●  You can use reports

-  Reports are available in a web site generated by Maven

-  Or in a quality dashboard like Sonar


Dependency Report


Sonar, a quality dashboard


Sonar, analyze your project


Sonar, Continuous Improvement ?


CONTINUOUS INTEGRATION Apache Maven


Continuous Integration ●  Setup a continuous integration server to :

-  Have a neutral and unmodified environment to run your tests

-  Quickly react when ●  The build fails (compilation failure for example) ●  A test fails ●  A quality metric is bad

-  Continuously improve the quality of your project and your productivity

●  Many products -  Hudson, Bamboo, TeamCity, Continuum,

Cruisecontrol, …


Hudson, how the weather is ?


Hudson : build, test, check


IDE Apache Maven


Eclipse ●  Integration from maven (eclipse:eclipse)

-  Allow many customizations -  Support many versions/variants of eclipse -  Support many usages (ear …) -  Doesn’t support projects with “pom” packaging -  Few support from dev team -  Many bugs in classpath management -  Asynchronous

●  You have to regenerate and reload project each time you change a POM)


Eclipse ●  Integration from eclipse (m2eclipse)

-  Synchronous -  Nice UI and services to edit POMs -  Support projects with “pom” packaging -  Doesn’t support all usages like EAR with WTP -  Doesn’t support very well a large number of modules -  Slow down eclipse on large projects because of a lack

of support of incremental build in Maven 2.x and its plugins


Eclipse (m2eclipse)


Eclipse (m2eclipse)


Eclipse (m2eclipse)


Idea IntelliJ


Netbeans


GOOD & BAD PRACTICES Apache Maven


KISS Apache Maven


K.I.S.S. ●  Keep It Simple, Stupid ●  Start from scratch

-  Do not copy/paste what you find without understanding ●  Use only what you need

-  It’s not because maven offers many features that you need to use them

●  Filtering ●  Modules ●  Profiles ●  …


PROJECT ORGANIZATION GOOD & BAD PRACTICES

Apache Maven


Project bad practices ●  Ignore Maven conventions

-  Except if your are migrating from something else and the target has to be to follow them.

-  Except if they are not compatible with your IDE ●  Different versions in sub-modules

-  In that case they are standalone projects. ●  Too many inheritance levels

-  It makes the POMs maintenance more complex -  Where should I set this plugin parameter ? In which parent ?


Project bad practices ●  Have too many modules

-  Is there a good reason ? ●  Technical constraint ? ●  Team organization ?

-  It increases the build time ●  Many more artifacts to generate ●  Dependencies resolution more complex

-  It involves more complex developments ●  More modules to import in your IDE ●  More modules to update …


Project good practices

●  Use the default inheritance : -  The reactor project is also

the parent of its modules. -  Configuration is easier :

●  No need to redefine SCM settings, site distribution settings …


POM GOOD & BAD PRACTICES Apache Maven


POM bad practices

●  Dependencies : -  DON’T confuse dependencies and

dependencyManagement ●  Plugins :

-  DON’T confuse plugins and pluginManagement -  DON’T use AntRun plugin everywhere -  DON’T let Maven choose plugins versions for you


POM bad practices ●  Profiles :

-  DON’T create environment dependant builds -  DON’T rely on dependencies coming from profiles

(there is no transitive activation of profiles) ●  Reporting and quality

-  DON’T activate on an existing project all reports with default configuration

-  DON’T control formatting rules without giving settings for IDEs.

●  DON’T put everything you find in your POM.


POM good practices ●  Set versions of dependencies in project parent’s

dependencyManagement ●  Set dependencies (groupId, artifactId, scope) in

each module they are used ●  Use the dependency plugin (from apache) and

versions plugin (from mojo) to analyze, cleanup and update your dependencies.


DEVELOPMENT GOOD & BAD PRACTICES

Apache Maven


Development bad practices ●  DON’T spend your time in the terminal, ●  DON’T exchange libraries through emails, ●  DON’T always use "-Dmaven.test.skip=true” ●  DON’T manually do releases


Development good practices ●  Keep up-to-date your version of Maven

-  For example in 2.1 the time of dependencies/modules resolution decreased a lot (Initialization of a project of 150 modules passed from 8 minutes to less than 1)

●  Use the reactor plugin (Maven < 2.1) or native reactor command line options (Maven >= 2.1) to rebuild only a subpart of your project : -  All modules depending on module XXX -  All modules used to build XXX

●  Try to not use Maven features not supported by your IDE (resources filtering with the plugin eclipse:eclipse)


USECASES Apache Maven


SECURE YOUR CREDENTIALS Apache Maven


Secure your credentials

-  arnaud@leopard:~$ mvn --encrypt-master-password toto {dZPuZ74YTJ0HnWHGm4zgfDlruYQNda1xib9vAVf2vvY=}

●  Generate a private key

<settingssecurity>!

<master>{dZPuZ74YTJ0HnWHGm4zgfDlruYQNda1xib9vAVf2vvY=}</master>!

</settingssecurity>!

●  We save the private key in ~/.m2/settings-security.xml


Secure your credentials -  <settingssecurity>

<relocation>/Volumes/ArnaudUsbKey/secure/settings-security.xml</relocation> </settingssecurity>!

●  You can move this key to another drive ~/.m2/settings.xml

●  You create an encrypted version of your server password

-  arnaud@mbp-arnaud:~$ mvn --encrypt-password titi{SbC9Fl2jA4oHZtz5Fcefp2q1tMXEtBkz9QiKljPiHss=}!

●  You register it in your settings

-  <settings> ... <servers> ... <server> <id>mon.server</id> <username>arnaud</username> <password>{SbC9Fl2jA4oHZtz5Fcefp2q1tMXEtBkz9QiKljPiHss=}</password> </server> ... </servers> ... </settings>!


BUILD A PART OF YOUR PROJECT Apache Maven


Using Reactor Options ●  Options added in maven 2.1 ●  Available in 2.0.x with the maven-reactor-plugin

-  But syntax is longer ●  Allow to control what you want to build in your

project


Using Reactor Options

-  arnaud@mbp-arnaud:~$ mvn install [INFO] ------------------------------------------------[INFO] Reactor Summary: [INFO] [INFO] Project ....................... SUCCESS [2.132s] [INFO] ModuleA ....................... SUCCESS [5.574s] [INFO] ModuleB ....................... SUCCESS [0.455s] [INFO] ModuleC ....................... SUCCESS [0.396s] [INFO] ModuleD ....................... SUCCESS [0.462s] [INFO] ModuleE ....................... SUCCESS [0.723s] [INFO] ModuleF ....................... SUCCESS [0.404s]!

●  Builds everything from A to F


Using Reactor Options -  arnaud@mbp-arnaud:~$ mvn install –pl

moduleE,moduleB [INFO] ------------------------------------------- [INFO] Reactor Summary: [INFO] [INFO] ModuleB .................. SUCCESS [2.774s] [INFO] ModuleE .................. SUCCESS [1.008s]

●  Builds only modules B and E ●  Following dependencies order ●  -pl --project-list: Build the

specified reactor projects instead of all projects


Using Reactor Options -  arnaud@mbp-arnaud:~$ mvn install –pl moduleD -am

[INFO] ------------------------------------------ [INFO] Reactor Summary: [INFO] [INFO] ModuleA ................. SUCCESS [4.075s] [INFO] ModuleB ................. SUCCESS [0.468s] [INFO] ModuleC ................. SUCCESS [0.354s] [INFO] ModuleD ................. SUCCESS [0.384s]

●  Builds module D (-pl) and all modules it uses as dependencies

●  -am --also-make: If a project list is specified, also make projects that the list depends on

●  Usecase : Build all modules required for a war, ear, …


Using Reactor Options -  arnaud@mbp-arnaud:~$ mvn install –pl moduleD -amd

[INFO] ------------------------------------------ [INFO] Reactor Summary: [INFO] [INFO] ModuleD ................. SUCCESS [4.881s] [INFO] ModuleE ................. SUCCESS [0.478s] [INFO] ModuleF ................. SUCCESS [0.427s]

●  Builds module D (-pl) and all modules which depend on it

●  -amd --also-make-dependents: If a project list is specified, also make projects that depend on projects on the list

●  Usecase : Check that a change in a module didn’t break others which are using it


Using Reactor Options -  arnaud@mbp-arnaud:~$ mvn install –rf moduleD

[INFO] ------------------------------------------ [INFO] Reactor Summary: [INFO] [INFO] ModuleD ................. SUCCESS [9.707s] [INFO] ModuleE ................. SUCCESS [0.625s] [INFO] ModuleF ................. SUCCESS [0.679s] [INFO] Project ................. SUCCESS [2.467s]

●  Restarts all the build from module D (-rf)

●  -rf,--resume-from <arg> : Resume reactor from specified project

●  Usecase : The build failed a 1st time in module D, you fixed it, and restart the build were it was to end it.


RELEASE YOUR PROJECT Apache Maven


Release of a webapp in 2002 ●  Limited usage of eclipse

-  No WTP (Only some features in WSAD), -  No ability to produce WARs


Release of a webapp in 2002 ●  Many manual tasks

-  Modify settings files -  Package JARs -  Copy libraries (external and internal) in a « lib »

directory -  Package WAR (often with a zip command) -  Tag the code (CVS) -  Send the package on the integration server using FTP -  Deploy the package with AS console


Release of a webapp in 2002 ●  One problem : The are

always problems -  Error in config files -  Missing dependencies -  Missing file -  Last minute fix which created a bug -  And many other possibilies ..

●  How long did it take ? -  When everything is ok : 15

minutes -  When there’s a problem : ½

day or more


Maven Release Plugin ●  Automates the release process from tagging

sources to binaries delivery ●  Release plugin main goals:

-  Prepare : To update maven versions and information in POMs and tag the code

-  Perform : To deploy binaries in a maven repository ●  After that you can just automate the deployment on

the AS using cargo for example.


Maven Release Plugin


Configuration and Prerequisites ●  Project version (must be a SNAPSHOT version) ●  Dependencies and plugins versions mustn’t be

SNAPSHOTs


SCM configuration

<scm> <connection> scm:svn:http://svn.exoplatform.org/projects/parent/trunk </connection> <developerConnection> scm:svn:http://svn.exoplatform.org/projects/parent/trunk </developerConnection> <url> http://fisheye.exoplatform.org/browse/projects/parent/trunk </url> </scm>

●  SCM binaries have to be in the PATH ●  SCM credentials have to already be stored or you have to

pass them in command line with : –Dusername=XXX –Dpassword=XXX


Distribution Management <project> <distributionManagement> <repository> <id>repository.exoplatform.org</id> <url>${exo.releases.repo.url}</url> </repository> . . . </distributionManagement> . . . <properties> <exo.releases.repo.url> http://repository.exoplatform.org/content/repositories/exo-releases </exo.releases.repo.url> . . . </properties> </project>


Repository credentials <settings>

<servers>

<server>

<!–- id must be the one used in distributionManagement -->

<id>repository.exoplatform.org</id>

<username>aheritier</username>

<password>{ABCDEFGHIJKLMNOPQRSTUVWYZ}</password>

</server>

</servers>

</settings>


Default Release Profile in Super POM <profile> <id>release-profile</id> <activation> <property> <name>performRelease</name> <value>true</value> </property> </activation> <build> <plugins> <!–- Configuration to generate sources and javadoc jars --> ... </plugins> </build> </profile>


Custom release profile <project>

...

<build>

<pluginManagement>

<plugins>

<plugin>

<groupId>org.apache.maven.plugins</groupId>

<artifactId>maven-release-plugin</artifactId>

<version>2.0-beta-9</version>

<configuration>

<useReleaseProfile>false</useReleaseProfile>

<arguments>-Pmyreleaseprofile</arguments>

</configuration>

</plugin>

</plugins>

</pluginManagement>

</build>

...

<profiles>

<profile>

<id>myreleaseprofile</id>

<build>

<!-– what you want to customize the behavior of the build when you do a release -->

</build>

</profile>

</profiles>

...

</project>


Troubleshooting Releases ●  Common errors during release:

-  Build with release profile was tested before and fails -  Local modifications -  Current version is not a SNAPSHOT -  SNAPSHOTs in dependencies and/or plugins -  Missing some configuration (scm, distribMgt, …) -  Tag already exists -  Unable to deploy project to the Repository -  Connection problems


BACK TO THE FUTURE Apache Maven


PRODUCT Apache Maven


Apache Maven 2.0.x ●  bugs fix ●  Last release : 2.0.11 ●  No other release of 2.0.x in the future


Apache Maven 2.x ●  Evolutions, new features ●  Several important new features in 2.1 like

-  Parallel downloads -  Encrypted passwords

●  Last release : 2.2.1


Apache Maven 3.x ●  Do not be afraid !!!!! ●  Not final before at least

one year ●  Full compatibility with

maven 2.x projects


Apache Maven 3.x ●  What’s new :

-  How POMs are constructed -  How the lifecycle is executed -  How the plugin manager executes -  How artifacts are resolved -  How it can be embedded -  How dependency injection is done


Apache Maven 3.x ●  What it will change for maven users ?

-  Any-source POM -  Versionless parent elements -  Mixins : a compositional form of Maven POM

configuration -  Better IDE integration -  Error & integrity reporting

●  Much improved error reporting where we will provide links to each identifiable problem we know of. There are currently 42 common things that can go wrong.

●  Don't allow builds where versions come from non-project sources like local settings and CLI parameters

●  Don't allow builds where versions come from profiles that have to be activated manually


Apache Maven 3.x ●  What it will change for maven developers ?

-  Lifecycle extension points -  Plugin extension points -  Incremental build support -  Queryable lifecycle -  Extensible reporting


Apache Maven 3.x ●  New tools

-  Tycho : OSGI, Eclipse -  Mvnsh


Maven Shell


COMMUNITY Apache Maven


Users community

●  90 days statistics ●  Number of subscribers in blue ●  Number of messages per day in red ●  http://people.apache.org/~coar/mlists.html

●  1780 subscribers on users mailing list


The web site


Dowloads

●  Per month downloads ●  http://people.apache.org/~vgritsenko/stats/projects/

maven.html


The team ●  60 committers, ●  More than 30 active in 2009, ●  Several organizations like Sonatype, deliver

resources and professional support, ●  A community less isolated : more interactions with

Eclipse, Jetty,


Commit Statistics


CONCLUSION Apache Maven


Conclusion ●  Today, Maven is widely adopted in corporate

environments, ●  It provides many services, ●  It has an important and really active community of

users and developers ●  Many resources to learn to use it and a

professional support are available ●  A product probably far from being perfect but on

rails for the future ●  Many things to do

-  We need you !


QUESTIONS ? Apache Maven


Licence et copyrights ●  Photos and logos belong to their respective

authors/owners ●  Content under Creative Commons 3.0

-  Attribution — You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work).

-  Noncommercial — You may not use this work for commercial purposes.

-  Share Alike — If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one.

●  http://creativecommons.org/licenses/by-nc-sa/3.0/us/


TO GO FURTHER … Apache Maven


DOCUMENTATIONS Apache Maven


Some links ●  The main web site :

-  http://maven.apache.org ●  Project’s team wiki :

-  http://docs.codehaus.org/display/MAVEN ●  Project’s users wiki :

-  http://docs.codehaus.org/display/MAVENUSER


Books ●  Sonatype / O’Reilly :

-  The Definitive Guide -  http://www.sonatype.com/

books -  Free download -  Available in several

languages ●  Soon in French


Books ●  Exist Global

-  Better builds with Maven -  http://www.maestrodev.com/

better-build-maven -  Free download


Books ●  Nicolas De loof

Arnaud Héritier -  Published by Pearson -  Collection Référence -  Based on our own

experiences with Maven. From beginners to experts.

-  In French only -  Available on 20th November


SUPPORT Apache Maven


Support ●  Mailing lists

-  http://maven.apache.org/mail-lists.html ●  IRC

-  irc.codehaus.org - #maven ●  Forums

-  http://www.developpez.net/ forum maven -  In French

●  Dedicated support -  Sonatype and some others companies


ANNEXE Apache Maven


Setup a global mirror <settings> <mirrors> <mirror>  <id>global-mirror</id> <mirrorOf>external:*</mirrorOf> <url>http://repository.exoplatform.org/content/groups/all</url> </mirror> </mirrors> <profiles> <profile> <id>mirror</id>   <repositories> <repository> <id>central</id> <url>http://central</url> <releases><enabled>true</enabled></releases> <snapshots><enabled>true</enabled></snapshots> </repository> </repositories> <pluginRepositories> <pluginRepository> <id>central</id> <url>http://central</url> <releases><enabled>true</enabled></releases> <snapshots><enabled>true</enabled></snapshots> </pluginRepository> </pluginRepositories> </profile> </profiles> <activeProfiles>  <activeProfile>mirror</activeProfile> </activeProfiles> </settings>

Technology

Geneva Jug (30th March, 2010) - Maven