1. Apache Maven 2 Overview
Part 2
Advanced Topics of Apache Maven 2
Anatoly Kondratyev
September 2012
30 January 2013
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2. The Goal
• Understand several Maven capabilities
• Build multi-module project with Maven
• Some special pom blocks
• Nexus configuration notes
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3. Maven in real world
WORKING WITH MULTI-MODULE
PROJECTS
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4. Project contents
GWT
application
EJB A EJB B
My Library
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5. What to do with Maven?
• 4 independent artifacts with dependencies
• Build in one step?
• Organize versioning?
• Keeping up to date?
• Wrong!
• Maven Inheritance and Aggregation
• Solves the above problems
• Right!
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6. Maven Inheritance & Aggregation
• <packaging>pom</packaging>
• Super pom
• Data in parent pom is inherited
• Maven dependency reactor
• Notes
• No cyclic dependencies
• No same modules
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7. Maven Inheritance & Aggregation
Parent
pom
EJB A EJB B Gwt My library
ejb ejb war jar
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8. Maven in action
<project …>
<modelVersion>4.0.0</modelVersion>
<groupId>ru.exigenservices</groupId>
<artifactId>my-parent</artifactId>
<version>1.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>EJB-A</module>
<module>EJB-B</module>
<module>Gwt</module>
<module>MyLibrary</module>
</modules>
</project>
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9. Maven in action
• What about deployment?
• EAR needed
• Special step needed
• Maybe divide frontend and backend?
• NB! One pom – one artifact
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10. Maven in action
Parent
pom
Frontend Backend
pom pom
Frontend Backend
Gwt EJB A EJB B My library
wrapper wrapper jar
war ear ejb ejb ear
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11. Multimodal hierarchy
• Parent pom
<project …>
<groupId>exigen</groupId>
<artifactId>parent</artifactId>
<version>1.0.1-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>backend</module>
<module>frontend</module>
</modules>
</project>
• Frontend pom
<project …>
<parent>
<groupId>exigen</groupId>
<artifactId>parent</artifactId>
<version>1.0.1-SNAPSHOT</version>
</parent>
<artifactId>frontend</artifactId>
<packaging>pom</packaging>
<modules>
<module>Gwt</module>
</modules>
</project>
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12. Dependency&Plugin management
• Changeable, overriddable and inheritable
• In parent
• GroupId & ArtifactId
• Version
• Everything you can configure
• Type, packaging
• In child
• GroupId & ArtifactId
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13. Dependency&Plugin Management
Parent:
<dependencyManagement>
<dependencies>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
<version>6.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
</dependencyManagement>
Child:
<dependencies>
<dependency>
<groupId>javax</groupId>
<artifactId>javaee-api</artifactId>
</dependency>
</dependencies>
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14. Flat vs Tree, Flat
.
|-- my-module
| `-- pom.xml
`--parent
`--pom.xml
• Pom.xml for my-module:
<project>
<parent>
<groupId>com.mycompany.app</groupId>
<artifactId>my-app</artifactId>
<version>1</version>
<relativePath>.../parent/pom.xml</relativePath>
</parent>
<modelVersion>4.0.0</modelVersion>
<artifactId>my-module</artifactId>
</project>
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15. Maven reactor
• Collects all the available modules to build
• Sorts the projects into the correct build order
• a project dependency on another module in the build
• different rules with plugins dependencies
• the order declared in the <modules> element (if no other rule
applies)
• Builds the selected projects in order
• Be aware of cycles and same modules on different
parents
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16. Conclusion
• Inheritance and aggregation
• Flat/Tree structure
• Maven reactor
• Dependency&Plugin management
• Deploy to Nexus/Weblogic problem
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17. What will help you
PROPERTIES, PROFILES,
EXECUTION BLOCKS
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18. Maven properties
• Just as common Ant properties
• ${property_name}
• Case sensitive
• Upper case for environment variables
• Dot(.) notated path
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19. Predefined properties
• Build in properties
• ${basedir} – directory with pom
• ${version} – artifact version
• Project properties
• ${project.build.directory}
• ${project.build.outputDirectory} (target/classes)
• ${project.name}
• ${project.version}
• Local user settings
• ${settings.localRepository}
• Environment properties
• ${env.M2_HOME}
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20. Maven profiles
• Maven profile – special way for configuring
build
• Different environments – different results
• Renaming
• Different build cycles
• Special plugin configuration
• Just different targets
• For different users
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21. Maven profiles
• Per project
• pom.xml
• Per user
• %USER_HOME%/.m2/settings.xml
• Per computer (Global)
• %M2_HOME%/conf/settings.xml
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22. Maven profiles
• Activation
• By hand (-P profile1,profile2)
• <activeProfiles>
• <activation>
• By environment settings
• By properties
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23. Maven profiles
<profiles>
<profile>
<activation>
<jdk>[1.3,1.6)</jdk>
</activation>
...
</profile>
<profile>
<activation>
<property>
<name>environment</name>
<value>test</value>
</property>
</activation>
...
</profile>
</profiles>
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24. Mojo
• Plugin
• Executing action
• Mojo – magical charm in hoodoo
• Just a Goal
• Plugin consists of Mojos
• Some parameters
• MOJO aka POJO (Plain-old-Java-object)
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25. Mojo
• When we should use mojos?
• Run from command line
• Different execution parameters for different
configurations
• Group of mojos from same plugin with
different configuration
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26. Execution blocks
Plugin:time
<plugin>
<groupId>com.mycompany.example</groupId>
<artifactId>plugin</artifactId>
<version>1.0</version>
<executions>
<execution>
<id>first</id>
<phase>test</phase>
<goals>
<goal>time</goal>
</goals>
<configuration> … </configuration>
</execution>
<execution>
<id>default</id>
…
<!– No phase block -->
</execution>
</executions>
</plugin>
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27. SCM SourceCodeManagement
• CVS, Mercurial, Perforce, Subversion, etc.
• Commit/update
• scm:bootstrap – build project
• Maven Release Plugin
• Snapshot  Version
• Check everything
• Commit
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28. Maven archetypes
• Create folders, poms, general stuff
• Archetype  Project
• For creating project:
• archetype:generate
• Select archetype from list
• Set up groupId, artifactId, version, …
• Get all project structure and draft files
• maven-archetype-quickstart
• For creating archetype:
• archetype:create-from-project
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29. Provided Arhetypes
• maven-archetype-archetype
• Sample archetype
• maven-archetype-j2ee-simple
• Simplified sample J2EE application
• maven-archetype-plugin
• Sample Maven plugin
• maven-archetype-quickstart
• Sample Maven project
• maven-archetype-webapp
• Sample Maven Webapp project
• More information:
http://maven.apache.org/archetype/maven-archetype-bundles/
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30. archetype:create-from-project
• Sample project
• mvn archetype:create-from-project
• src catalog
• Pom.xml (maven-archetype)
• Some resources
• Modify code (…targetgenerated-sourcesarchetype)
• archetype-metadata.xml
• Update properties and default values; review
• Go to target, run “mvn install”
• To test archetype
“mvn archetype:generate -DarchetypeCatalog=local”
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31. Good configuration - great advantage
NEXUS
SETTING.XML
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32. Sonatype Nexus
• Artifact repository
• Nexus and Nexus Pro
• Rather simple
• Widely used
• Other Maven Repository Managers
• Apache Archiva
• Artifactory
• Comparison
http://docs.codehaus.org/display/MAVENUSER/Maven+Repository+Manager+Fe
ature+Matrix
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33. Nexus hints
• Nexus configuration + local configuration
• Proxy repositories
• Add everything and cache it!
• Add to Public Repositories group
• Restrictions on uploading artifacts
• UI: Artifact Upload
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34. Settings.xml
• Servers • Profile
<servers>
<profiles>
<server>
<profile>
<id>nexus</id>
<id>nexus</id>
<username>…</username>
<repositories>
<password>…</password>
<repository>
</server>
<id>central</id>
</servers>
<url>http://central</url>
• Mirrors (2.0.9) <releases>
<mirrors> <enabled>true</enabled>
<mirror> <updatePolicy>never</updatePolicy>
<id>nexus</id> </releases>
<mirrorOf>*</mirrorOf> <snapshots>
<url>http://localserver:8081/nexus/content/groups/public/ <enabled>true</enabled>
</url> </snapshots>
</mirror> </repository>
</mirrors> </repositories>
• Active Profile <pluginRepositories>
<activeProfiles> …
</pluginRepositories>
<activeProfile>nexus</activeProfile>
</profile>
</activeProfiles>
</profiles>
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35. updatePolicy
• UpdatePolicy
• Always
• Daily (default)
• Interval:X (X – integer in minutes)
• Never
• Repository Snapshots
• Enabled true/false
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36. When you have free time…
LICENSE, ORGANIZATION, DEVELOPER
S, CONTRIBUTORS
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37. Licenses
• How your project could be used?
<licenses>
<license>
<name>The Apache Software License, Version 2.0</name>
<url>http://www.apache.org/licenses/LICENSE-2.0.txt</url>
<distribution>repo</distribution>
<comments>A business-friendly OSS license</comments>
</license>
</licenses>
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38. Organization
• Just tell everybody!
<organization>
<name>Exigen Services</name>
<url>http://www.exigenservices.ru/</url>
</organization>
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39. Developers & Contributors block
• Id, name, email
• Organization, organizationUrl
• Roles
• Timezone
• Properties
• Contributors don’t have Id
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40. Developers block
<developers>
<developer>
<id>anatoly.k</id>
<name>Anatoly</name>
<email>Anatoly.Kondratiev@exigenservices.com</email>
<organization>Exigen</organization>
<organizationUrl>http://www.exigenservices.ru/</organizationUrl>
<roles>
<role>Configuration Manager</role>
<role>Developer</role>
</roles>
<timezone>+3</timezone>
<properties>
<skype>anatoly.kondratyev</skype>
</properties>
</developer>
</developers>
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41. Final notes
• A great amount of plugins
• Ant-run
• Mirrors on local repo, not on computer
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42. Now it’s your turn…
QUESTIONS
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