My Maven presentation on Liferay Nordic Symposium 2012

1. Developing Liferay Plugins with
Maven
Mika Koivisto
Senior Software Engineer

2. Agenda
• Quick Introduction to Maven
• Liferay Maven Support
• Demo
• Future Plans

3. Quick Introduction to Maven
• Project management tool (build, test, report, assemble,
release)
• Small core expandable with plugins
• Convention over configuration
• Dependency management
• Common lifecycle

4. Typical Ant build.xml
<project name="my-project" default="dist" basedir=".">
<property name="src" location="src/main/java"/>
<property name="build" location="target/classes"/>
<property name="dist" location="target"/>
<target name="init">
<tstamp/>
<mkdir dir="${build}"/>
</target>
<target name="compile" depends="init" description="compile the source " >
<javac srcdir="${src}" destdir="${build}"/>
</target>
<target name="dist" depends="compile">
<mkdir dir="${dist}/lib"/>
<jar jarfile="${dist}/lib/MyProject-${DSTAMP}.jar" basedir="${build}"/>
</target>
<target name="clean">
<delete dir="${build}"/>
<delete dir="${dist}"/>
</target>
</project>

5. Same in Maven
<project>
<modelVersion>4.0.0</modelVersion>
<groupId>com.liferay.sample</groupId>
<artifactId>my-project</artifactId>
<version>1.0-SNAPSHOT</version>
</project>

6. The Project Object Model
• Analogous to Makefile or build.xml
• Versioned <major>.<minor>.<increment>-<qualifier>
• Packaging (pom, jar, war, ejb, ear, etc.)
• Inheritance
• Sub-modules
• Dependencies
• Profiles
• Properties

7. Dependency Management
• Declarative
• Transitive
• Identified by: groupId, artifactId, version and type
combination
• Scoped: compile, provided, runtime, test or system

8. Build Lifecycle
• Build-in lifecycles: default, clean and site
• Lifecycles have phases
• Goals are attached to phases
• Common phases:
• clean
• compile
• test
• package
• install
• deploy

9. Repositories
• Place where all artifacts are stored
• Local
• Located in USER_HOME/.m2/repository
• Cached copy of downloaded artifacts
• Contains locally installed artifacts
• Remote
• Central
• Internal or external
• Proxy or Cache

10. What is Artifact?
• Product of build
• Described by pom.xml
• Identified with combination of groupId, artifactId, version
and qualifier

11. What is Archetype?
• Project template
• Available for various project types
• Run mvn archetype:generate to create interactively or
specify with parameters
mvn archetype:generate
-DarchetypeArtifactId=liferay-portlet-archetype
-DarchetypeGroupId=com.liferay.maven.archetypes
-DarchetypeVersion=6.1.0
-DgroupId=com.liferay.sample
-DartifactId=sample-portlet
-Dversion=1.0-SNAPSHOT
-DinteractiveMode=false

12. Liferay Maven Support
• Alternative to ant based plugins sdk
• Compatible with both Liferay 6.1 CE and EE
• CE Portal Artifacts published to Maven Central
Repository
• EE Portal Artifacts downloadable from Customer Portal
• Liferay Maven Plugin and Archetypes published to Maven
Central Repository for both CE and EE

13. Liferay Portal Artifacts
• GroupId: com.liferay.portal
• ArtifactId:
• portal-client
• portal-impl
• portal-service
• portal-web
• support-tomcat
• util-bridges
• util-java
• util-taglib

14. Liferay Maven Plugin
• GroupId: com.liferay.maven.plugins
• ArtifactId: liferay-maven-plugin
• Brings features from Plugins SDK to Maven
• Service Builder
• Theme diffs
• Direct Deployment

15. Liferay Maven Plugin Goals
• liferay:build-ext
• liferay:build-lang
• liferay:build-service
• liferay:build-thumbnail
• liferay:build-wsdd
• liferay:deploy
• liferay:direct-deploy
• liferay:theme-merge

16. Liferay Archetypes
• GroupId: com.liferay.maven.archetypes
• ArtifactId:
• liferay-ext-archetype
• liferay-hook-archetype
• liferay-layouttpl-archetype
• liferay-portlet-archetype
• liferay-servicebuilder-archetype
• liferay-theme-archetype
• liferay-web-archetype

17. Demo

18. Parent Project
• Vaguely equivalent to plugins sdk instance
• Includes all the project modules such as:
• Portlets
• Themes
• Layouts
• Contains common project properties such as used Liferay
version

19. Sample Parent Project Pom
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.liferay.sample</groupId>
<artifactId>helloworld-project</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<properties>
<liferay.version>6.1.10</liferay.version>
<liferay.auto.deploy.dir>/opt/liferay-portal-6.1.10-ee-ga1/deploy</liferay.auto.deploy.dir>
</properties>
</project>

20. Theme Module
• Merges with parent theme
during packaging
• Parent theme defined in
pom.xml
• Parent can be built-in theme
or any war artifact
• Deploy with
mvn liferay:deploy
or
mvn liferay:direct-deploy -DdeployDir=/
opt/liferay/tomcat/webapps

21. Service Builder Module
• Creates separate portlet and
service api sub projects
• Build service from -portlet
mvn liferay:build-service
• Deploy from -portlet
mvn liferay:deploy
or
mvn liferay:direct-deploy -DdeployDir=/
opt/liferay/tomcat/webapps

22. Ext Plugin Module
• Similar structure to plugins
sdk but mavenized
• Build service from -ext-impl
mvn liferay:build-service
-DserviceFileName=src/main/resources/
com/liferay/sample/service.xml
• Deploy from -ext
mvn liferay:build-service
-DserviceFileName=src/main/resources/
com/liferay/sample/service.xml

23. Maven Best Practices
• Setup internal repository and maven proxy
• Reduces build time by caching dependencies
• Increases build stability and repeatability
• Allows enforcing company policies
• Never use 3rd party SNAPHOT dependencies
• Declare all your dependencies and don’t rely on transitive
dependencies for classes you use

24. Future Plans
• IDE integration
• Liferay IDE
• Liferay Developer Studio
• More archetypes (liferay faces, spring mvc, etc.)
• Liferay Bundle Builder

25. Contributing
• Github project
https://github.com/liferay/liferay-maven-support
• JIRA
http://issues.liferay.com/browse/MAVEN

26. Contact
Email: mika.koivisto@liferay.com
Twitter: @koivimik
Github: mikakoivisto