Data Structures Maven Project

This project is a Java-only version of DataStructures that uses Maven, a popular build automation tool for Java projects maintained by the Apache Software Foundation. It supercedes Ant, which is also maintained by Apache.

Maven makes the software build lifecycle less error-prone. Dependency management is simplified since it uses the Maven Central Repository, the de facto repository for Java projects, comparable to PyPI for Python projects and npm for JavaScript projects.

A Maven project has at its root folder:

• A pom.xml file, which defines dependencies, plugins, etc.
  • pom stands for Project Object Model
• A src folder, which includes source code (in main/) and test code (in test/)
• A target folder, which includes generated files (compiled code, documentation, coverage reports, .jar files, etc.)
  • This folder is excluded from source control
• An optional README.txt file explaining the project (this file, which uses Markdown instead)

The pom.xml file is of paramount importance to a Maven project. Dependencies, which are located under the <dependencies> element, need the following tags:

• groupId
• artifactId
• version
• scope, which is usually one of: compile, test, runtime
  • Choose the right scope depending on how you use the dependency

Maven utilizes plugins to get things done:

• Maven phases are mapped to plugin:goal pairs; e.g. compile maps to compiler:compile
  • You can read more here

Maven commands defined by this project:

• mvn checkstyle:checkstyle runs the Checkstyle utility
• mvn compile compiles the source code into the target folder
• mvn test-compile runs mvn compile and compiles the test code into the target folder, but doesn't run unit tests
• mvn test runs mvn test-compile and runs all unit tests, and produces a JaCoCo code coverage report
• mvn package runs mvn test and if all tests pass, creates a .jar file of the project in the target folder
• mvn install runs mvn package and installs the created .jar file in ~/.m2/repository/, which is where all Maven dependencies get installed
• mvn javadoc:javadoc generates Javadoc documentation of the source code
• mvn site builds a static website for the project, including the Checkstyle and Javadoc pages
• mvn clean deletes the target folder
• mvn versions:use-latest-releases updates all dependency version numbers in pom.xml
  • Run mvn dependency:resolve to install those updated dependencies

Maven commands can be combined, e.g. mvn clean test forces a clean test run by deleting the target folder before running the unit tests.