src/site/apt/what-is-maven.apt - maven-site - Git at Google

  ------
  What is Maven?
  ------
  Jason van Zyl
  ------
  12 October 2005
  ------

 Introduction

  Maven was originally started as an attempt to simplify the build
  processes in the Jakarta Turbine project. There were several
  projects each with their own Ant build files that were all slightly
  different and JARs were checked into CVS. We wanted a standard way to
  build the projects, a clear definition of what the project consisted
  of, an easy way to publish project information and a way to share JARs
  across several projects.

  The result is a tool that can now be used for building and managing
  any Java-based project. We hope that we have created something that
  will make the day-to-day work of Java developers easier and generally
  help with the comprehension of any Java-based project.

 Maven's Objectives

  Maven's primary goal is to allow a developer to comprehend the
  complete state of a development effort in the shortest period of
  time. In order to attain this goal there are several areas of concern
  that Maven attempts to deal with:

  * Making the build process easy

  * Providing a uniform build system

  * Providing quality project information

  * Providing guidelines for best practices development

  * Allowing transparent migration to new features

 * Making the build process easy

  While using Maven doesn't eliminate the need to know about the
  underlying mechanisms, Maven does provide a lot of shielding
  from the details.

 * Providing a uniform build system

  Maven allows a project to build using its project object model (POM) and
  a set of plugins that are shared by all projects using
  Maven, providing a uniform build system. Once you familiarize yourself
  with how one Maven project builds you automatically know how all Maven
  projects build saving you immense amounts of time when trying to
  navigate many projects.

 * Providing quality project information

  Maven provides plenty of useful project information that is in
  part taken from your POM and in part generated from your project's
  sources. For example, Maven can provide:

  * Change log document created directly from source control

  * Cross referenced sources

  * Mailing lists

  * Dependency list

  * Unit test reports including coverage

  []

  As Maven improves the information set provided will improve, all of
  which will be transparent to users of Maven.

  Other products can also provide Maven plugins to allow their set of
  project information alongside some of the standard information given by
  Maven, all still based on the POM.

 * Providing guidelines for best practices development

  Maven aims to gather current principles for best practices development, and
  make it easy to guide a project in that direction.

  For example, specification, execution, and reporting of unit tests are part of
  the normal build cycle using Maven.
  Current unit testing best practices were used as guidelines:

  * Keeping your test source code in a separate, but parallel source tree

  * Using test case naming conventions to locate and execute tests

  * Have test cases setup their environment and don't rely on customizing the build  for test preparation.

  []

  Maven also aims to assist in project workflow such as release management and
  issue tracking.

  Maven also suggests some guidelines on how to layout your project's directory structure
  so that once you learn the layout you can easily navigate any other project that uses
  Maven and the same defaults.

 * Allowing transparent migration to new features

  Maven provides an easy way for Maven clients to update their installations
  so that they can take advantage of any changes that been made to
  Maven itself.

  Installation of new or updated plugins from third parties or Maven itself has
  been made trivial for this reason.

 What is Maven Not?

  You may have heard some of the following things about Maven:

  * Maven is a site and documentation tool

  * Maven extends Ant to let you download dependencies

  * Maven is a set of reusable Ant scriptlets

  []

  While Maven does these things, as you can read above in the "What is Maven?" section,
  these are not the only features Maven has, and it's objectives are quite different.

  Maven does encourage best practices, but we realise that some projects may not fit with
  these ideals for historical reasons.  While Maven is designed to be flexible, to an extent, in these
  situations and to the needs of different projects, it can not cater to every situation without making
  compromises to the integrity of its objectives.

  If you decide to use Maven, and have an unusual build structure that you cannot reorganise, you may
  have to forgo some features or the use of Maven altogether.
	------
	What is Maven?
	------
	Jason van Zyl
	------
	12 October 2005
	------

	Introduction

	Maven was originally started as an attempt to simplify the build
	processes in the Jakarta Turbine project. There were several
	projects each with their own Ant build files that were all slightly
	different and JARs were checked into CVS. We wanted a standard way to
	build the projects, a clear definition of what the project consisted
	of, an easy way to publish project information and a way to share JARs
	across several projects.

	The result is a tool that can now be used for building and managing
	any Java-based project. We hope that we have created something that
	will make the day-to-day work of Java developers easier and generally
	help with the comprehension of any Java-based project.

	Maven's Objectives

	Maven's primary goal is to allow a developer to comprehend the
	complete state of a development effort in the shortest period of
	time. In order to attain this goal there are several areas of concern
	that Maven attempts to deal with:

	* Making the build process easy

	* Providing a uniform build system

	* Providing quality project information

	* Providing guidelines for best practices development

	* Allowing transparent migration to new features

	* Making the build process easy

	While using Maven doesn't eliminate the need to know about the
	underlying mechanisms, Maven does provide a lot of shielding
	from the details.

	* Providing a uniform build system

	Maven allows a project to build using its project object model (POM) and
	a set of plugins that are shared by all projects using
	Maven, providing a uniform build system. Once you familiarize yourself
	with how one Maven project builds you automatically know how all Maven
	projects build saving you immense amounts of time when trying to
	navigate many projects.

	* Providing quality project information

	Maven provides plenty of useful project information that is in
	part taken from your POM and in part generated from your project's
	sources. For example, Maven can provide:

	* Change log document created directly from source control

	* Cross referenced sources

	* Mailing lists

	* Dependency list

	* Unit test reports including coverage

	[]

	As Maven improves the information set provided will improve, all of
	which will be transparent to users of Maven.

	Other products can also provide Maven plugins to allow their set of
	project information alongside some of the standard information given by
	Maven, all still based on the POM.

	* Providing guidelines for best practices development

	Maven aims to gather current principles for best practices development, and
	make it easy to guide a project in that direction.

	For example, specification, execution, and reporting of unit tests are part of
	the normal build cycle using Maven.
	Current unit testing best practices were used as guidelines:

	* Keeping your test source code in a separate, but parallel source tree

	* Using test case naming conventions to locate and execute tests

	* Have test cases setup their environment and don't rely on customizing the build for test preparation.

	[]

	Maven also aims to assist in project workflow such as release management and
	issue tracking.

	Maven also suggests some guidelines on how to layout your project's directory structure
	so that once you learn the layout you can easily navigate any other project that uses
	Maven and the same defaults.

	* Allowing transparent migration to new features

	Maven provides an easy way for Maven clients to update their installations
	so that they can take advantage of any changes that been made to
	Maven itself.

	Installation of new or updated plugins from third parties or Maven itself has
	been made trivial for this reason.

	What is Maven Not?

	You may have heard some of the following things about Maven:

	* Maven is a site and documentation tool

	* Maven extends Ant to let you download dependencies

	* Maven is a set of reusable Ant scriptlets

	[]

	While Maven does these things, as you can read above in the "What is Maven?" section,
	these are not the only features Maven has, and it's objectives are quite different.

	Maven does encourage best practices, but we realise that some projects may not fit with
	these ideals for historical reasons. While Maven is designed to be flexible, to an extent, in these
	situations and to the needs of different projects, it can not cater to every situation without making
	compromises to the integrity of its objectives.

	If you decide to use Maven, and have an unusual build structure that you cannot reorganise, you may
	have to forgo some features or the use of Maven altogether.