Kay Gaensler CC BY-NC-SA 2.0 https://www. ickr.com/photos/gaensler/5465098412 Maven 102 fl Best Practices Brian Demers Open Source Developer BrianDemers bdemers

Topics • Maven Demysti cation • Speed up your build • Things to Commit or Omit • Memes fi @BrianDemers | bdemers

Who is this guy? @BrianDemers | bdemers

source: Silicon Valley @BrianDemers | bdemers

VS @BrianDemers | bdemers

VS @BrianDemers | bdemers

VS @BrianDemers | bdemers

Developer Productivity Engineering @BrianDemers | bdemers

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Dependency Hell Last Commit: 2010-06-28 @BrianDemers | bdemers

Dependencies are a tree $ mvn dependency:tree junit-jupiter +- junit-jupiter-api | +- opentest4j | +- junit-platform-commons | - apiguardian-api +- junit-jupiter-params - junit-jupiter-engine source: pngitem.com - Anastasiya Alferova @BrianDemers | bdemers - junit-platform-engine

scans.gradle.com @BrianDemers | bdemers

Your Application Dependencies Your code @BrianDemers | bdemers

@BrianDemers | bdemers

Maven Build Lifecycle • • • • • • • • • • • • validate initialize generate-sources process-sources generate-resources process-resources compile process-classes generate-test-sources process-test-sources generate-test-resources process-test-resources @BrianDemers | bdemers • • • • • • • • • • • test-compile process-test-classes test prepare-package package pre-integration-test integration-test post-integration-test verify install deploy

Maven Build Lifecycle Phase process-resources compile process-test-resources test-compile test package install deploy @BrianDemers | bdemers Plugin Goal resources:resources compiler:compile resources:testResources compiler:testCompile surefire:test jar:jar install:install deploy:deploy

Maven Build Lifecycle Phase process-resources compile process-test-resources test-compile test package verify install deploy @BrianDemers | bdemers Plugin Goal resources:resources compiler:compile resources:testResources compiler:testCompile surefire:test jar:jar pmd:check, checkstyle:check, jacoco:check install:install deploy:deploy

@BrianDemers | bdemers

Plugin Con guration fi @BrianDemers | bdemers

Plugin Con guration fi @BrianDemers | bdemers

Plugin Con guration (example) $ mvn buildnumber:create

global config

[INFO] Storing buildNumber: 6231815 $ mvn buildnumber:create

execution config

[INFO] Storing buildNumber: 623181597908f815cb9af206a389e739d80435a5 fi @BrianDemers | bdemers

Custom Maven Plugins @Mojo(name = “roll”, defaultPhase = LifecyclePhase.VERIFY) public class DiceMojo extends org.apache.maven.plugin.AbstractMojo { @Parameter(property = “expression”, defaultValue = “1d20”) private String expression; public void execute() throws MojoExecutionException, MojoFailureException { getLog().info(“Dice eval: ” + Dice.roll(expression)); } } @BrianDemers | bdemers

Commit or Omit! @BrianDemers | bdemers

Dependency Ranges source: xkcd.com/2247 @BrianDemers | bdemers

Dependency Ranges @BrianDemers | bdemers Range Meaning (,1.0] x <= 1.0 (,1.0) x < 1.0 [1.0] x == 1.0 [1.0,) x >= 1.0 (1.0,) x > 1.0 (1.0,2.0) 1.0 < x < 2.0 [1.0,2.0] 1.0 <= x <= 2.0 (,1.0],[1.2,) x <= 1.0 or x >= 1.2. Multiple sets are comma-separated (,1.1),(1.1,) x != 1.1

Pin Versions https://area-b.com/blog/2019/05/04/1210/ @BrianDemers | bdemers

Separate Unit and Integration Tests @BrianDemers | bdemers

Use Pro les headshots: xkcd.com fi @BrianDemers | bdemers

Test Jars T S E T @BrianDemers | bdemers

Uberjars Stop using the Maven Shade Plugin @BrianDemers | bdemers

Source jars E C R U O S @BrianDemers | bdemers

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Build Cache @BrianDemers | bdemers

Parallel Builds @BrianDemers | bdemers

Multiple Threads Project-A Project-B api model impl service app core utility webapp @BrianDemers | bdemers

Project-B model service core webapp @BrianDemers | bdemers utility

Test w/ Multiple Threads JVM OneTest.java @BrianDemers | bdemers TwoTest.java ThreeTest.java FourTest.java

Test w/ Multiple JVMs (forkCount) @BrianDemers | bdemers JVM JVM OneTest.java ThreeTest.java TwoTest.java FourTest.java

Test w/ Multiple JVMs & Multiple Threads JVM OneTest.java @BrianDemers | bdemers JVM TwoTest.java ThreeTest.java FourTest.java

source: https://levelup.gitconnected.com/be-careful-with-java-parallel-streams-3ed0fd70c3d0 @BrianDemers | bdemers

“The future is always beginning now.” –Mark Strand @BrianDemers | bdemers

Daemon Builds are faster If you keep the JVM running @BrianDemers | bdemers

4.0.0 @BrianDemers | bdemers

Questions? Thank you! BrianDemers bdemers Learn more & get free swag