Maven - ilya-khadykin/notes-outdated GitHub Wiki

TODO:

• https://www.tutorialspoint.com/maven/maven_build_life_cycle.htm

• Build automation tool

• Apache Software Foundation

• Created in 2003

• Current version: 3.3.* (2016-06-23)

Convention over configuration

• Maven is a build tool
• Dependency management tool
• Project management tool
• Standardized approach to building software
• Command line tool
• IDE integration

Maven provides developers ways to manage following:

• Builds
• Documentation
• Reporting
• Dependencies
• SCMs
• Releases
• Distribution
• mailing list

Maven uses Convention over Configuration which means developers are not required to create build process themselves.

In order to build the project, Maven provides developers options to mention life-cycle goals and project dependencies (that rely on Maven pluging capabilities and on its default conventions). Much of the project management and build related tasks are maintained by Maven plugins.

POM stands for Project Object Model. It is fundamental Unit of Work in Maven. It is an XML file. It always resides in the base directory of the project as pom.xml.

The POM contains information about the project and various configuration detail used by Maven to build the project(s).

POM also contains the goals and plugins. While executing a task or goal, Maven looks for the POM in the current directory. It reads the POM, gets the needed configuration information, then executes the goal. Some of the configuration that can be specified in the POM are following:

• project dependencies
• plugins
• goals
• build profiles
• project version
• developers
• mailing list

Before creating a POM, we should first decide the project group (groupId), its name(artifactId) and its version as these attributes help in uniquely identifying the project in repository.

POM is an .xml file

• describes, configures and customizes a Maven Project
• Maven reads the pom.xml file to build a project
• defines the "address" for the project artifact using a coordinate system
• specifies project information, plugins, goals, dependencies and profiles

All POMs inherit from a parent (despite explicitly defined or not). This base POM is known as the Super POM, and contains values inherited by default.

Maven use the effective pom (configuration from super pom plus project configuration) to execute relevant goal. It helps developer to specify minimum configuration detail in his/her pom.xml. Although configurations can be overridden easily.

An easy way to look at the default configurations of the super POM is by running the following command:

mvn help:effective-pom

• hold build artifacts and dependencies of varying types
• Local repositories (local cache)
• remote repositories
• local repository takes precedence during dependency resolution

The Central Repository

• Plugin is a collection of goals
• Example: compiler plugin
• Goals perform the actions in Maven builds
• All work is done via plugins and goals
• Called independently or as part of a lifecycle phase

• Lifecycle is a sequence of named phases
• Phases are executed sequentially
• 3 lifecycles: clean, default, site
• Executing a phase executes all previous phases

Executing install phase:

mvn install

Follow the instructions on the official website - http://maven.apache.org/

<project>
	<modelVersion>4.0.0</modelVersion>
	<artifactId>maven-hello-world</artifactId>
	<groupId>com.example.maven.demo</groupId>
	<version>1.0</version>
	<packaging>jar</packaging>
</project>

Build with mvn package

More info - https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html

Base pom.xml is located in C:\apache-maven-3.3.9\lib\maven-model-builder-3.3.9.jar (Windows)

You can configure your environment using <profiles>

<profiles>
  <profile>
    <id>production</id>
  </profile>
</profiles>

Run created production profile with mvn -Pproduction package

Environment variable should be set up in OS

<activation>
  <property>
    <name>env.PACKAGE_ENV</name>
    <value>PROD</value>
  <property>
</activation>

mvn -DmyVariable=someValue install

mvn site - create a static web site about the project based on information from pom.xml mvn help:effective-pom - see the actual pom.xml with all inherited settings mvn archetype:generate - create pom.xml from template

You can configure proxy settings in ${MAVEN_HOME}\conf\settings.xml

    <proxy>
      <id>optional</id>
      <active>true</active>
      <protocol>http</protocol>
      <username>proxyuser</username>
      <password>proxypass</password>
      <host>proxy.host.net</host>
      <port>80</port>
      <nonProxyHosts>local.net|some.host.com</nonProxyHosts>
    </proxy>

Local repository is stored in ${USER_HOME}/.m2/repository (~/.m2/repository) by default

settings.xml placed in ${USER_HOME}/.m2/ (~/.m2/)

• https://www.safaribooksonline.com/library/view/learning-apache-maven/9781771373661/