Overview of Maven and Ant for Java builds, with some comparison and contrast.

1. Pasadena Java Users Group
pasadenajug.org
Java Builds
with Ant & Maven
Feb 23, 2009
David Noble
dnoble@g2ix.com

2. About Me
David Noble
Sr Solutions Architect
Exist Global / G2iX

3. About You
Ant users? Ivy?

Maven users?

Continuous integration?


4. Build Tool
Collect inputs

Process inputs

Generate final outputs


5. Build Tool - Inputs
Source code

Java, SQL

Resources

Properties, XML

Dependencies

Libraries, components, frameworks


6. Build Tool - Processing
Compile

Run tests

Copy files

Replace keywords

Package

Install / deploy


7. Build Tool - Outputs
JAR / WAR / EAR files

Zip files

Reports


8. Ant Maven
Procedural Declarative
1. Set path 1. Define name & version
2. Compile jars 2. Define as WAR project
3. Run unit tests 3. Specify dependencies
4. Create reports 4. Specify unit test plugin
5. Copy files
6. Assemble WAR

9. Ant
“make for java”

Properties, paths, and filesets

Targets

Target dependencies

Tasks


10. Ant Installation
Download

Unzip

Add to PATH
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Set ANT_HOME env variable
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Extend by adding jars to lib/
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Customize by modifying XSL in etc/


11. Ant Project Definition
build.xml
Project name

Property variables

Paths

Tasks

Targets


12. Ant Properties
<property name=quot;lib.dirquot; value=quot;libquot;/>
From command line

In build.xml
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From external XML
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From external property files
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From environment
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13. Ant Paths
<path id=quot;classpathquot;>
<fileset dir=quot;${lib.dir}quot; includes=quot;**/*.jarquot;/>
</path>
<target name=quot;compilequot;>
<mkdir dir=quot;${classes.dir}quot;/>
<javac srcdir=quot;${src.dir}quot; destdir=quot;${classes.dir}quot; classpathref=quot;classpathquot;/>
</target>

14. Ant Targets
Name

Description

Dependencies

Conditionals (if, unless)

<antcall> task


15. Ant Tasks
Core tasks

Optional tasks
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Custom tasks

Third party

Write your own


16. Selected Core Tasks
Ant AntCall Apply Basename BuildNumber Checksum
Chmod Concat Condition Copy Cvs Delete DependSet
Dirname Ear Echo EchoXML Exec Fail Filter FixCRLF Get
Import Input Jar Java Javac Javadoc Length LoadFile
LoadProperties LoadResource MakeURL Mail MacroDef
Manifest ManifestClassPath Mkdir Move Nice Parallel
Patch PathConvert PreSetDef Property Record Replace
ResourceCount Retry Rmic Sequential SignJar Sleep Sql
Subant Sync Tar Taskdef Tempfile Touch Truncate TStamp
Typedef Unjar Untar Unwar Unzip Uptodate Waitfor
WhichResource War XmlProperty XSLT Zip

17. Ant Multi-Project Builds
Option 1 – Master build.xml

Option 2 – Cascading build.xml's


18. Ant Scripting
<macrodef> task

<script> task


19. Ivy for Dependencies
build.xml
<project xmlns:ivy=quot;antlib:org.apache.ivy.antquot;
name=quot;hello-ivyquot; default=quot;runquot;>
<target name=quot;resolvequot;>
<ivy:retrieve />
</target>
</project>

20. Ivy for Dependencies
ivy.xml
<ivy-module version=quot;2.0quot;>
<info organisation=quot;apachequot; module=quot;hello-ivyquot;/>
<dependencies>
<dependency org=quot;commons-langquot;
name=quot;commons-langquot; rev=quot;2.0quot;/>
<dependency org=quot;commons-cliquot;
name=quot;commons-cliquot; rev=quot;1.0quot;/>
</dependencies>
</ivy-module>

21. Ivy Repositories
Maven artifact repositories

Build your own


22. Ivy Reports

23. Ant Ecosystem
IDE plugins

Custom tasks


24. More Ant
Ant
http://ant.apache.org/
Core tasks
http://ant.apache.org/manual/coretasklist.html
External tools
http://ant.apache.org/external.html
IVY
http://ant.apache.org/ivy/

25. Maven
Project and artifact-based build

platform
Uses repositories to manage

artifacts and third party libraries
Customized by modifying the

behavior of the life-cycle via plugins.

26. Maven

27. Maven Artifacts
Output of the build process

JARs, WARs, EARs, zip files

Stored in repositories

Published and consumed by Maven

One per project


28. Maven Dependencies
Items needed during build process

Managed as artifacts and metadata

within remote repositories
Usually created and published by

other Maven builds
Though not necessarily


29. Maven Dependencies
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.2</version>
<scope>test</scope>
</dependency>

30. Maven Directory Structure
pom.xml

src/

target/


31. Maven Directory Structure
src

main

com/example/app/App.java

test

com/example/app/AppTest.java


32. Maven Directory Structure
target

classes/

generated-classes/

site/

surefire-reports/

test-classes/

webdemo-1.0-SNAPSHOT.war


33. Maven Project Object Model
“POM”

Fundamental unit of work in Maven

Build components inherit from best

practices and common base

34. Maven Build Life-Cycle
Consistent pattern

Portable process knowledge

Modify build with plugins

Extensible in decoupled way

Large number of phases, not all

required
Compile, test, package, install, deploy


35. Default Lifecycle Phases
validate, initialize

generate-sources, process-sources
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generate-resources, process-resources
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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


36. Site Lifecycle Phases
Pre-site: executes processes

Site: generates documentation

Post-site: executes processes

Site-deploy: copies files


37. Clean Lifecycle Phases
Pre-clean: executes processes

Clean: removes files

Post-clean: executes processes


38. Phases have Goals
generate-resources ear:generateApplicationXml
process-resources resources:resources
package ear:ear
install install:install
deploy deploy:deploy

39. Maven Settings
Two setting files

Installation settings:

conf/settings.xml in install directory

User settings: ~/.m2/settings.xml

C:Usersusername on Windows Vista

C:Documents and Settingsusername on XP


40. Maven Settings
Separate installation and user settings
User settings are things you don't share

server usernames and passwords, local paths, etc.

Installation settings are things that should

be the same on all Maven installations
can distribute various ways: check out Maven install

from SCM, provide a re-bundled Maven, etc.

41. Maven Archetypes
POJO jar

Web applications

AppFuse, Wicket, MyFaces, etc

Groovy


42. Maven Archetypes
mvn archetype:generate

Application structure

Code generation

Plugin

Distributed in repositories


43. Maven Resources
Accessed by code at runtime

Not required for compilation

Packaged within the artifact

Can be filtered with custom values


44. Maven Plugins
Reusable pieces of build functionality

Perform a clearly defined task based on a set of

input configuration
Maven takes responsibility for orchestrating their

execution
Primarily written in Java, but can be written in a

number of scripting languages
Are also stored and downloaded from repositories


45. Maven Repositories
Repositories are a storage location for artifacts

Maven has two types:

Remote repository - repository accessible over HTTP, FTP, filesystem, etc that

contains artifacts to consume and as a place to publish build artifacts
Local repository - a cache of artifacts on your machine, downloaded from

several remote repositories
Maven is pre-configured to use the Central Repository for

dependencies
A large collection of open source and re-distributable artifacts,

primarily for Java
Can establish and manage your own remote repositories

Can be used by build systems other than Maven


46. Repository Servers
Archiva

Artifactory

Nexus


47. Archiva
Helps to manage Maven repositories

Control your environment for your

team
Can be run personally for offline

cache

48. Archiva
A repository management server

manages Maven remote repositories and the artifacts inside them

Used by a group or team for an “internal” remote repository

deploy your own build artifacts

control content from external sources

on demand downloading of artifacts

CI server companion

Can be used as a personal server

make it easier to clean your local repository without downloading remotely again

must be careful about introducing build inconsistencies localized to your

environment, however

49. Installing Archiva
Two choices

Existing servlet container or application server

Standalone

pre-configured instance of Jetty 6, Java Service Wrapper, Apache Derby

Configuration files

APP_BASE/conf/jetty.xml - server port, outgoing mail server and databases

standalone only, configure using container settings for others

APP_BASE/conf/archiva.xml - maintained by the application

applies to both choices

Two databases – users and repository statistics

When using standalone, recommend a separate conf directory

set ARCHIVA_BASE environment variable to point to a copy of the conf directory

makes upgrading easier


50. Configuring Maven For Archiva
There are a number of alternatives for configuring Maven to use a repository

manager:
add to the POM

used in addition to central, but always checked first

add to Maven settings

as above, but applies to all projects

override or mirror central

never use the central repository, everything else the same

override or mirror all repositories given

Could add the repositories to the POM

what if the parent POM is in the repository, not the check out?

use the POM if users must build using that repository without configuring settings

Use Maven settings instead

generally prefer the mirror all repositories


51. Maven
Archetypes

Artifacts

POM – Project Object Model

Dependencies

Directory structure

Plugins (testing, reporting, deploying, etc)

Repositories


52. Maven Ecosystem
IDE support

Artifact repositories

Plugins

Continuous integration


53. Maven Companies

54. Maven Links
Maven
http://maven.apache.org/
Archiva
http://archiva.apache.org/
Artifacts
http://mvnrepository.com/
Free Books
http://www.exist.com/better-build-maven/
http://www.sonatype.com/book

55. Credits
Special thanks to Carlos Sanchez and Brett Porter
for their inputs and material from their training slides

56. Thanks!
David Noble
dnoble@g2ix.com
www.dnoble.org