Tohuwabohu excorcism

Maven is an project automation tool. All the routine work can be automated by one maven script: e.g. compiling, project1 and project2, generating websites, run the tests.

1. Maven can manage Maven-artifacts, which are uniquely identified by: groupId, artifactId, version.
2. Maven artifacts can depend on other Maven artifacts.
3. Maven downloads required artifacts, which the local artifacts depend from - all into one local repository:

   C:\Users\<username>\.m2

4. Maven has an own Project type in Eclipse. Each Maven Project is a Maven artifact.

• install - installiert in Lokale Repo
• deploy - installiert ins Nexus

mvn phasename

Examples:

mvn clean
mvn deploy
mvn install

Achtung: Executing a phase - executes all phases up to the executed phase!
Executing:

mvn clean

does

process-resources
compile
process-test-resources
test-compile
test
package
install

mvn myplugin:myGoal

Examples:

mvn jboss-as:deploy
mvn dependency:copy-dependencies

You can mix up executing phases (e.g. clean or package) with goal-execution of some plugins (e.g. dependency:copy-dependencies)
Examples:

mvn clean dependency:copy-dependencies package

Child POMs override parent Pom's nodes on default.
How to change this behaviour is described here: http://blog.sonatype.com/people/2011/01/maven-how-to-merging-plugin-configuration-in-complex-projects/

To avoid this error during mvn clean install assign more space to Java. Use an environment variable MAVEN_OPTS

set MAVEN_OPTS=-Xmx1024m

mvn dependency:tree -Dincludes="this.is.your.gorup.id:this.is.the.artifact.id"

mvn org.fusesource.mvnplugins:maven-graph-plugin:RELEASE:reactor

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">

	<profiles>
	
		<profile>
			<repositories>
				<repository>
				  <id>maven2-central-remote</id>
				  <name>maven2-central-remote</name>
				  <url>https://mydomain.com/artifactory/maven2-central-remote</url>
				</repository>
				
				<repository>
					<id>maven2-priv</id>
					<name>maven2-priv</name>
					<url>https://mydomain.com/artifactory/maven2-priv</url>
				</repository>

			</repositories>
			
			<pluginRepositories>
			  <pluginRepository>
				<id>maven2-central-remote</id>
				<url>https://mydomain.com/artifactory/maven2-central-remote</url>
			  </pluginRepository>

			  <pluginRepository>
				<id>center</id>
				<url>https://repo1.maven.org/maven2/</url>
			  </pluginRepository>

			  <pluginRepository>
				<id>jcenter</id>
				<url>https://jcenter.bintray.com</url>
			  </pluginRepository>
			  
			  
			</pluginRepositories>
			
			<id>bt</id>
		</profile>
	</profiles>

	<activeProfiles>
		<activeProfile>bt</activeProfile>
	</activeProfiles>


	<proxies>
		<proxy>
			<active>true</active>
			<host>111.122.3.44</host>
			<port>9400</port>
			<nonProxyHosts>mydomain.com|*.mydomain.com</nonProxyHosts>
		</proxy>
	</proxies>
	
	<servers>
		<server>
			<id>maven2-priv</id>
			<username>username@domain.com</username>
			<!-- encrypted pass or api token from artifactory profile -->
			<password>XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX</password>
		</server>
		<server>
			<id>maven2-priv-snap</id>
			<username>username@domain.com</username>
			<!-- encrypted pass or api token from artifactory profile -->
			<password>XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX</password> <!-- encrypted pass -->
		</server>
	</servers>

</settings>

Now you can add the following to your projects pom.xml

<project ....
  <pluginRepositories>
    <pluginRepository>
      <id>maven2-priv</id>
      <url>https://domain.com/artifactory/maven2-priv/</url>
    </pluginRepository>
  </pluginRepositories>
 
  <distributionManagement>
    <repository>
      <uniqueVersion>false</uniqueVersion>
      <id>maven2-priv</id>
      <name>maven2-priv</name>
      <url>https://domain.com/artifactory/maven2-priv</url>
      <layout>default</layout>
    </repository>
    <snapshotRepository>
      <uniqueVersion>false</uniqueVersion>
      <id>maven2-priv-snap</id>
      <name>maven2-priv</name>
      <url>https://domain.com/artifactory/maven2-priv</url>
      <layout>default</layout>
    </snapshotRepository>
  </distributionManagement>
  ...
</project>

# The following command deploys the artifact to the Artifactory.

 
mvn clean install
mvn clean deploy 

• The Word SNAPSHOT is interpreted by Maven, if it is contained inside the version string.
• The Word SNAPSHOT is interpreted during install or deploy phases. Inside the target folder the filename will still contain SNAPSHOT. After deploy it will be replaced.
• The Word SNAPSHOT is expanded to a qualifier, e.g. to date and time.

Example:

target: 1.0-SNAPSHOT
deploy: 1.0-20080207-230803-1

Frther there is an OSGI Version too. It is called qualifier. It is replaced by a timestamp in maven plugins.

Maven manages the dependencies transitively. Here are the rules, about how maven resolves dependencies: https://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Dependency_Scope

Scope is a concept, which allows to say, that dependency X is only available at runtime, or should not be inherited transitively.

Scopes:

Syntax to use the profile jetty

mvn clean install -P jetty

If you keep the a part of the xml-structure and insert the structure between the <profile></profile> tags.

Define some plugins which will only be used when profile jetty is enabled

		<!-- profile to start jetty -->
		<profile>
			<id>jetty</id>
			<build>
				<plugins>			
					<plugin>
					...
					</plugin>
				</plugins>
			</build>
		</profile>

You can use properties to configure the usual build

<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">
	<modelVersion>4.0.0</modelVersion>
	<artifactId>de.updatesite.customplugins.site</artifactId>
	<name>de.updatesite</name>
	<description>updatesite</description>
	<packaging>${package.method}</packaging>

		<!-- profile to start jetty will be packaged as pom -->
		<profile>
			<properties>
				<package.method>pom</package.method>
			</properties>
		</profile>
...