mvn -version

mvn -help

mvn clean

mvn package

mvn help:effective-pom

mvn dependency:tree

mvn dependency:go-offline

mvn dependency:purge-local-repository

mvn dependency:sources

mvn help:describe -Dcmd=clean

mvn test                 # run all tests
mvn -Dtest=ServiceImplTest test                     # run all tests in a class
mvn -Dtest=ServiceImplTest#specificTest test        # run a specific test in a class
mvn -Dtest=ServiceImplTest#specificTest* test       # run a specific tests in a class using pattern

mvn package -Dmaven.test.skip=true                  # skip running all tests
mvn package -DskipTests                             # skip running surefire tests
mvn package -DskipITs                               # skip running failsafe integration tests

mvn package -P <profile-1>,<profile-2>              # activing profiles
mvn package -P !<profile-1>,<profile-2>             # use the ! to deactive a profile 

mvn help:active-profiles

mvn clean release:prepare

Note: Maven will ask you for the release (select default) and the snapshot (select default), 
two files will be created a backup of the POM and a release.properties file.

mvn release:prepare -DdryRun=true

Note: dryRun will will put not change anything but ive us the output, good for checking before you run for real.

mvn release:perform

Note: This will also deploy (Packagecloud or Nexus for example)

mvn release:rollback

Note: this will remove the backup POM, remove the release.properties file and rollback the <version>, 
however it won't update github this has to be done manually.

## This defines the XML version and any encoding, the XML declaration describes some of the most general properties of 
## the document, telling the XML processor that it needs an XML parser to interpret this document

<?xml version="1.0" encoding="UTF-8"?>

## This is the top level element and defines the schema used and any namespaces, also defines all the rules and elements that can be used

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

## This element indicates what version of the object model this POM is using.

<modelVersion>4.0.0</modelVersion>

## indicates the unique identifier of the organization or group that created the project. The groupId is one of the key 
## identifiers of a project and is typically based on the fully qualified domain name of your organization

<groupId>uk.co.datadisk</groupId>

## This element indicates the unique base name of the primary artifact being generated by this project. The primary artifact 
## for a project is typically a JAR file. Secondary artifacts like source bundles also use the artifactId as part of their 
## final name

<artifactId>hello-world</artifactId>

## This element indicates the version of the artifact generated by the project. Maven goes a long way to help you with version 
## management and you will often see the SNAPSHOT designator in a version, which indicates that a project is in a state 
## of development

<version>0.0.1-SNAPSHOT</version>

## Maven properties are value placeholder, their values are accessible anywhere within a POM by using the notation ${X}, 
## where X is the property, or they can be used by plugins as default values

<properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>11</java.version>
        <maven.compiler.source>${java.version}</maven.compiler.source>
        <maven.compiler.target>${java.version}</maven.compiler.target>
    </properties>

## Any dependencies required will be automatically downloaded from the Maven Repository

<dependencies>
    <dependency>
        <groupId>org.apache.commons</groupId>
        <artifactId>commons-lang3</artifactId>
        <version>3.8.1</version>
    <dependency>
</dependencies>