Intermediate Maven Michael Youngstrom

Notes This is a training NOT a presentation Please ask questions No making fun of my microphone Prerequisites – Introduction to Maven – Basic Java and XML skillz

Outline Review Introduction to Maven Plugins Properties Profiles

Review Maven is a build tool Maven project Structure Maven has a build lifecycle A maven artifact is identified with GAV Maven dependencies are glorious!

Maven Plugins Plugins extend Maven Plugins are identified with GAV Two ways to execute a plugin – Hook into build lifecycle – Invoke standalone

Hooking into build lifecycle Allows plugin to execute as part of maven build Three items to configure a plugin: – Phase – Goal – Configuration

Plugin Example... org.apache.maven.plugins maven-enforcer-plugin execute validate enforce...

Plugin Documentation Use Plugin reference documentation! Full NameDefault PhaseConfiguration

Plugin Configuration Configuration parameters go in the configuration element false... true

PluginManagement PluginManagement configures a plugin without executing it – Version – Configuration – Executions To execute use: – Regular Plugin entry – Plugin standalone command

Plugin Management Example org.apache.maven.plugins maven-enforcer-plugin true org.apache.maven.plugins maven-enforcer-plugin

Plugin Inheritance This is a rather complex topic Plugin inherits PluginManagement configuration Plugins and PluginManagement can inherit config from parent Beyond that you can figure it out on your own

How to Manage POM Complexity Effective POM – Flattens POM configuration – Dependency and DependencyMangement is resolved – Plugin and PluginManagement is resolved – Executions are Resolved – Properties are Resolved (more on this later) – Profiles are Resolved (more on this later) To use: – Select the “Effective POM” tab in pom editor in Eclipse – Invoke mvn help:effective-pom on command line

Invoking Plugins Standalone Plugins can also be invoked adhoc from command line – GroupId:ArtifactId:Version:Goal – Will use Plugin Management configuration – Configuration can be provided by system properties Can be shortened Must be configured in pom plugin or in settings.xml mvn org.apache.maven.plugins:maven-enforcer-plugin:1.0:enforce mvn enforcer:enforce

Plugin Documentation Helps Plugin reference documentation rocks! Short NameFull Name

Setting Configuration Standalone Expression: the property key to this parameter Expression Key mvn enforcer:enforce –Denforcer.fail=false

Lab 1: Maven Plugins _1_Maven_Plugins

Maven Properties Properties are the glue that tie configuration together Properties can come from several places: – element in pom – System Properties – Project Object Model Properties can be used as a value just about anywhere – Plugin Configuration – Resource Filtering Properties can only be simple primitive values

Maven Property Example... true org.apache.maven.plugins maven-enforcer-plugin 1.0 ${skipEnforcer}

POM Properties Element Properties can be nested... true ${skipTests}

System Properties Supplied to the command line using “-D” – mvn install –DskipEnforcer=true Supplied in the IDE using parameters dialog System Properties override POM properties

Project Object Model Properties Properties can be derived from POM structure POM elements = property keys – Expression: ${project.version} Element: – Expression: ${project.artifactId} Element: – Expression: ${project.build.sourceDirectory Special properties: – ${basedir}: Directory of current project – ${maven.build.timestamp} : Start of build.

Inherited Properties Properties can be inherited and overridden Current property value depends upon context... true ${skipTests}... false

Resource Filtering Project resources can use properties Resources filtered in process-resources phase Filtering can be turned off on a per resource directory basis Some Text File in /src/main/resources: ${someProperty} Some Text File in /src/main/resources: SomeValue... SomeValue

Properties and Plugin Expression Properties can also override plugin expression defaults Expression Key

Skip Enforcer Example #1... org.apache.maven.plugins maven-enforcer-plugin 1.0 true

Skip Enforcer Example #2 true org.apache.maven.plugins maven-enforcer-plugin 1.0

Skip Enforcer Example #3 org.apache.maven.plugins maven-enforcer-plugin 1.0 mvn clean install –Denforcer.skip=true

Lab 2: Maven Properties _2_Maven_Properties

Maven Profile Allows activating a set of alternative configurations Works for: – Properties – Dependencies – Plugins – etc. Inherits and extends non-profile configuration

Profile Example... enforcer false

Profile Activation Can be Activated: – By Default – Explicitly by name – Based on a Property – Based on operation system – Existence of a file

Activation from Command Line Activates a profile explicitly Multiple profile ids are comma delimited mvn clean install –P enforcer

Activation in IDE Build Can be set in build command configuration

Activation in IDE Development Can be set in project’s Maven config Usually used to change development mode

Lab 3: Maven Profiles _3_Maven_Profiles

Summary Plugins extend Maven’s capabilities Properties are the glue in Maven configuration Profiles enable alternate configurations Next training understanding Stack Starter’s Maven Configuration