Maven - a2z

Maven  

1)  Introduction  :

Maven is  a  Build tool

Maven  provides

->  Compile the source code.
            ->   Generate jar, war, ear.
            ->  Deployment
            ->  Generate the reports like code quality, code coverage.
            ->  Generate the documentation.


  Maven’s project goal

Maven's primary goal is to allow a developer to understand the complete state of a project in the shortest period of time.

  Maven’s Objectives

• It makes the build process easy.
• Provides a uniform building system.
• Provides quality related project information .
• Provides guidelines related to development to meet the best goal.
• Allows transparent migration to new features.

Maven’s Features

• 
  
• Superior dependency management.
• A large repository of libraries and metadata.
• Multiple projects handling.
• Extensible, easy to write plug-in.
• Coherent site of project information.
• Multiple language support – C++, Java …
• Maintainability: stop building the build. Focus on the application.

2)  Maven Software Installation :

-> It is an opensource software
-> It is in the form of zip file
-> Download maven.zip freely from  http://apache.osuosl.org/maven/maven-3/3.5.4/binaries/apache-maven-3.5.4-bin.zip
             
                 

After extracting the maven zip file, the  maven root folder will be having

           bin  ->  mvn.bat
           conf -- settings.xml
           lib  -- jar
           plugins - predefined.



->  Latest version   : 3.5.x
            from  3.3 -- JDK 1.7 or above is using
              < maven 3.3  --  jdk 1.6 is using.


Note :  Q)  How to enable maven software ?


 Maven is completely written in java,  so it must compatible with the respective Java version


In windows operating systems -  >  Properties -> settings ->environment variables  set below

JAVA_HOME = C:\Program Files\Java\jdk1.8.0_131
Path  = C:\Program Files\Java\jdk1.8.0_131\bin  or  %JAVA_HOME%/bin

Maven project structure

2) Importance of pom.xml


A Project Object Model or POM is the fundamental unit of work in Maven. It is an XML file that contains information about the project and configuration details used by Maven to build the project.


--> Pom stands for project objective model.
->  It contains information about how to generate jar, war, ear and also how to generate the reports like codequality, code coverage..

->  Every pom.xml  have  3 elements are mandatory.

          1.  Groupid     -    group name for jar, war, ear
          2.  Artifactid    -  jar  or war or ear name
          3.  Version       --  version of jar or war

Examples :
---------------

   com.dev21(Groupid)  :  FirstApp(Artifactid) : 1.0-SNAPSHOT ( version)

Always  the combination should be unique.

pom.xml :
------------

<project>
   <groupid>com.dev21</groupid>
    <artifcatid>FirstApp</artifactid>
      <version>1.0-SNAPSHOT</version>
   
     <packaging> jar or war or ear or pom


      </packaging>



</project>

Maven command operations

Types of Repositories :


1.  Local Repository  --  C:\Users\Sreenu\.m2

2.  Remore Repository  -   client rep  -- https://www.repo.hdfc.com/archive/project

3.  Central Repository  -   https://repo.maven.org/artifacts/projects/..

Note :  When we run the maven project first  maven will look into local repo to find the dependencies.
If it is found then get from local rep.

-->  If it is not found in local repo then it will go central repo, if it is found in central then get the dependencies from central repo.

-->  If it is not found in central repo then it will go remote repo, if it is find in remote repo then get the dependencies from remote repo else it will give error no artifact found.

8)  Importance of settings.xml



-->   settings.xml  file will configure locations of local repo and remote repo.
-->   First maven software will read the pom.xml and start the search in local repo which is configured in settings.xml file.

-->   The default local rep location  :  C:\Users\Sreenu\.m2  if you want we can update the new local repo location in settings.xml

-->   maven software will refere new local repo instead of



9)  Types of pom.xml

a)  Normal  pom.xml
b)  Parent  pom.xml
c)   Super pom  or  Effective pom.xml
d)   Aggregator pom  or modules pom

Aggregator or modules pom.xml

Maven is the most popular Java Dependency Management Tool.

Thanks for referring this article,  well, you may get  much knowledge/learn all below areas by end of this article.

• Use Maven to Manage Dependencies
• Use Maven to create Multi Module Projects
• Understand Maven Best Practices
• Use Maven Commands
• Understand Maven Build Life Cycle and Project Object Model
• Understand Maven's philosophy of "Convention over Configuration"
• Use Maven to generate Projects using Maven Archetypes
• Use Maven Plugins
• Understand how to use Maven in combination with an IDE like Eclipse

We can automate  all below listed ones using  Maven :

• Compiling Java Code
• Running Unit Tests
• Building Jar's and Wars
• Running web applications in Tomcat
• Setting up new projects

Let's build some sample projects using  below  important  Maven :

• Dependency Management - including Transitive Dependencies
• Maven Project Object Model
• Maven Build Life Cycle
• Maven Plugins
• Maven Archetypes - Generate Projects
• Maven Best Practices
• Multi Module Maven Projects

Target audience?

• You want to use Maven to manage Dependencies
• You want to use Maven to create New Projects
• You have familiarity with Java Programming
• You want to understand Maven Best Practices and a few Maven Tips and Tricks
• You want to understand how Maven Works

Requirements

• You should have familiarity with Java Programming.
• You should have access to internet to download and setup Maven and Eclipse
• We will help you setup Maven and Eclipse
• You should be ready to have fun doing a lot of hands-on stuff

Topics

1)  Maven Basics

                       a : Magic of Maven - How does it help a developer?

                       b : Setting up Your First Maven Project

                       c : Your First Maven Dependency

                       d : Understand How to Build a Jar

                       e : Maven Goals - compile, test and install

                       f : Understand Maven Build Life Cycle 

2)  Maven Dependency Management
                         

•                            Understand Maven POM - Project Object Model
•                            Transitive Dependencies
•                            Excluding Dependencies in Maven
•                           Scope of a Dependency
•                            Versioning of Dependencies

3)  How does Maven Work?

•               Maven Super POM and Effective POM - Convention over Configuration
•               Understand How Maven Downloads dependencies - effective-settings
•               Let's Play with Maven Plugins
•               Maven from Command Line

4)  Advanced Maven

• Basics of Multi Module Maven Project
• Best Practices of Multi Module Maven Project
• Running Web Application in Tomcat
• Maven Commands - Tips and Tricks
• Creating Projects with Maven Archetypes

5)  Conclusion