Maven follows a predefined and well-defined build lifecycle that consists of a series of phases and goals. Each phase represents a specific step in the build process, and within each phase, one or more goals are executed. The build lifecycle ensures that project compilation, testing, packaging, and deployment tasks are carried out in a consistent and standardized manner. The three main build lifecycles in Maven are:
Default Build Lifecycle:
The default build lifecycle is the most commonly used and consists of the following phases:
- validate: Validates the project's structure and configuration.
- compile: Compiles the source code of the project.
- test: Executes unit tests using a suitable unit testing framework (e.g., JUnit).
- package: Packages the compiled code into a distributable format, such as a JAR or WAR.
- verify: Runs any checks on the results of integration tests to ensure the quality of the build.
- install: Installs the packaged artifact into the local repository for use as a dependency in other projects.
- deploy: Deploys the final artifact to a remote repository for sharing with other developers or projects.
Clean Build Lifecycle:
The clean build lifecycle is responsible for cleaning up artifacts created during the build process. It consists of the following phases:
- pre-clean: Executes any necessary tasks before the project is cleaned.
- clean: Deletes all files generated by the previous build.
- post-clean: Executes any necessary tasks after the project is cleaned.
Site Build Lifecycle:
The site build lifecycle is used to generate a project's site documentation. It consists of the following phases:
- pre-site: Executes any necessary tasks before generating the site documentation.
- site: Generates the site documentation for the project.
- post-site: Executes any necessary tasks after generating the site documentation.
- site-deploy: Deploys the generated site documentation to a remote repository or server.
To execute a specific phase of a build lifecycle, you use the mvn command followed by the phase name. For example, to compile the project, you run mvn compile, and to package the project, you run mvn package. By running one phase, all preceding phases in the lifecycle will be executed automatically.
Maven plugins are used to implement the goals associated with each phase. Maven's build lifecycle and plugin architecture make it easy to build and manage complex projects with consistent and repeatable build processes. Developers can customize the build process by configuring plugins, but the default lifecycle is usually sufficient for most projects.