What is Maven, What is Archetype and Creating a Maven Project

Issues with legacy build frameworks(ANT)

Earlier with Ant, if we have to build a java project we need to put the logic for every task like compile, run in the build.xml. Though, these tasks are common across all the java projects. There is no way we can reuse. Below are some of the other pain points in Ant build framework.

  1. Writing the logic for Project folder creation
  2. Download and copy all the dependent Jars into your project
  3. Writing the logic for reusable tasks like compile, test, run

What is Maven?


Maven is an alternative build framework which addresses all the pain points mentioned above. Though its usage is not limited to build, in this post we will limit the scope to build itself.

we will see how maven simplifies the above concerns. 

What is Archetype?


Maven maintains a template for each project type and calls this template as Archetype. These archetypes exist for almost every project type in the maven repository. There are archetypes exists for Java Web app, Hibernate, Spring MVC etc.,  

Each Archetype maintains what it takes to create a project type. It includes folder structure, libraries, sample java prototypes etc., So, we can use these archetypes for setting up the projects. This is a fast way of setting up the project. If you are not happy with this approach. You can add your project dependencies manually to your maven file.

Creating a project from Archetype(aka template)

When we install maven on a windows machine, a folder .m2 will be created in C drive(in windows) where .m2 is your Maven local repository.

 Your local repository is more or less a clean slate. Inside .m2 folder, you should see 'archetype-catalog.xml'(fig1) (catalog file of remote repository) which represents a list of archetypes from maven central repository. This file is required if we want to create a project using Archetype.
(If this file is file is not present you should download this file from the link: http://repo.maven.apache.org/maven2/archetype-catalog.xml)


fig1:archetype-catalog.xml












Once you copy this file to your local repositories you will be able to access all the archetypes in the Maven repositories. So, we have the setup ready. Let's start creating a simple Spring boot project using a Maven archetype.

Below are the steps for creating for creating a maven Spring boot project(for example) in eclipse IDE. 

Step-1 

Below screenshot shows the list of archetypes available with fresh installation of Maven. Eclipse parses the 'archetype-catalog.xml' file and shows the archetype list.  Here, we see there is no Spring boot archetype for creating the Spring boot project. Because, default maven installation does not contain every artifact. We will have to download the additional artifacts by clicking on Configure.




Step-2

 I have added the repository location of Spring by clicking on Configure-> Add Remote Catalog


Step-3

 After adding the remote repository location of Spring, I could access the Spring-boot archetype. I selected the Archetype and proceeded to next screen






















 Step-4

 For every archetype(Project template), there are some place holders left for the user to fill in.we will be filling in those details on the last screen.

 Group Id: Package structure
Artifact Id: <Artifact-Name>.jar
Version: 0.0.1-SNAPSHOT (In Development Phase) or 0.0.1(After Released)
Package: Project Name
















This completes the Maven project creation. And you can see the project gets created in eclipse.


Comments

Post a Comment

Popular posts from this blog

Distributed database design using CAP theorem

Image
CAP is a theorem/standard which can be applied while designing distributed systems like distributed databases. A distributed database is a set of databases(nodes) which are spread across the network.  These set of databases(nodes) in the distributed database can be either designed as either a  master/slave  or a  sharded model . Consistency -  Database should return the latest write on the DB. Availability -  Database should return data in a decent amount of time .  But, the data might not be latest. Partition tolerant - I n spite of n/w failure, the database should always be available. A distributed database can be designed either as a CP, AP, CA but not with all the 3 capabilities.  AP - Available and Partition tolerant  -  Sharded model (Data is distributed, No Master)  -      Availability  - Because, the data is distributed, any of the nodes can return the data. So, always availabl...
Continue Reading »

LDAP - Basics

Image
What is LDAP? LDAP is a protocol used by clients for accessing the directory server. What is a directory server? The directory server is a storage server which is widely used to store user's data of any organization. It uses LDAP protocol to listen to client requests for performing any read/write operations on it.  Since the directory servers support LDAP protocol for interacting with clients, they are also called as LDAP servers. Who are the clients to directory server? Directory clients can be anything which is capable of interacting with the directory server. Examples of directory clients can be a java application, Apacheds studio (Apache DS studio is similar to SQL developer or TOAD for Oracle), etc.  How data in LDAP servers gets stored? Data in LDAP server gets stored in a directory.  When we add entries to the LDAP, they get stored under the base directory. Some of the entries may contain subentries also. Eventually, This result in data stor...
Continue Reading »

Easy approach to work with files in Java - Java NIO(New input output)

  NIO - New IO package. Introduced in 1.4. It is buffer based and non-blocking. Hence, faster than IO package. It supports symbolic links, posix file attributes(works only on OS's which are POSIX compliant), ACL (Access control list). Paths and Files are the main classes Creating a potential file reference: Path path = Paths.get("c:/demo/"); //possible file reference Creating a directory, file, write to the file, read from the file: //create all the non existing directories in the path. Ignores creating a directory, if that directory already exists Path directories = Files.createDirectories("c:/demo/example1/properties/"); Path newFilePath = Files.createFile("c:/demo/README.txt"); //Creating a file //Writting bytes to the file Files.write(newFilePath, "This is a dummy text".getBytes(StandardCharsets.UTF_8)); //Reading bytes from file String readFile = new String(Files.readAllBytes(newFilePath), "UTF-8"); Files.readAllBytes reads all...
Continue Reading »