Maven Tutorials: Maven Lifecycle, Phases & Goal


What is Lifecycle?

A life cycle is a series of stages a living thing goes through during its life. All plants and animals go through life cycles. It is helpful to use diagrams to show the stages, which often include starting as a seed, egg, or live birth, then growing up and reproducing. Life cycles repeat again and again.

But we use life cycle keyword in non-living world as well. Any object or creation including software dev has lifecycle.

Human Lifecycle

Software Development Life Cycle

Build Lifecycle in Maven for Managing Software Build Process

Maven is based around the central concept of a build lifecycle. What this means is that the process for building and distributing a particular artifact (project) is clearly defined.

For the person building a project, this means that it is only necessary to learn a small set of commands to build any Maven project, and the POM will ensure they get the results they desired.

There are three built-in build lifecycles: default, clean and site. The default lifecycle handles your project deployment, the clean lifecycle handles project cleaning, while the site lifecycle handles the creation of your project’s web site.

Maven defines 3 lifecycles in META-INF/plexus/components.xml:

Each of these build lifecycles is defined by a different list of build phases, wherein a build phase represents a stage in the lifecycle.

For example, the default lifecycle comprises of the following phases (for a complete list of the lifecycle phases, refer to the Lifecycle Reference):

  • validate – validate the project is correct and all necessary information is available
  • compile – compile the source code of the project
  • test – test the compiled source code using a suitable unit testing framework. These tests should not require the code be packaged or deployed
  • package – take the compiled code and package it in its distributable format, such as a JAR.
  • verify – run any checks on results of integration tests to ensure quality criteria are met
  • install – install the package into the local repository, for use as a dependency in other projects locally
  • deploy – done in the build environment, copies the final package to the remote repository for sharing with other developers and projects.

These lifecycle phases (plus the other lifecycle phases not shown here) are executed sequentially to complete the default lifecycle. Given the lifecycle phases above, this means that when the default lifecycle is used, Maven will first validate the project, then will try to compile the sources, run those against the tests, package the binaries (e.g. jar), run integration tests against that package, verify the integration tests, install the verified package to the local repository, then deploy the installed package to a remote repository.

Lifecycle Reference

The following lists all build phases of the defaultclean and site lifecycles, which are executed in the order given up to the point of the one specified.

Clean Lifecycle

PhaseDescription
pre-cleanexecute processes needed prior to the actual project cleaning
cleanremove all files generated by the previous build
post-cleanexecute processes needed to finalize the project cleaning

Default Lifecycle

PhaseDescription
validatevalidate the project is correct and all necessary information is available.
initializeinitialize build state, e.g. set properties or create directories.
generate-sourcesgenerate any source code for inclusion in compilation.
process-sourcesprocess the source code, for example to filter any values.
generate-resourcesgenerate resources for inclusion in the package.
process-resourcescopy and process the resources into the destination directory, ready for packaging.
compilecompile the source code of the project.
process-classespost-process the generated files from compilation, for example to do bytecode enhancement on Java classes.
generate-test-sourcesgenerate any test source code for inclusion in compilation.
process-test-sourcesprocess the test source code, for example to filter any values.
generate-test-resourcescreate resources for testing.
process-test-resourcescopy and process the resources into the test destination directory.
test-compilecompile the test source code into the test destination directory
process-test-classespost-process the generated files from test compilation, for example to do bytecode enhancement on Java classes.
testrun tests using a suitable unit testing framework. These tests should not require the code be packaged or deployed.
prepare-packageperform any operations necessary to prepare a package before the actual packaging. This often results in an unpacked, processed version of the package.
packagetake the compiled code and package it in its distributable format, such as a JAR.
pre-integration-testperform actions required before integration tests are executed. This may involve things such as setting up the required environment.
integration-testprocess and deploy the package if necessary into an environment where integration tests can be run.
post-integration-testperform actions required after integration tests have been executed. This may including cleaning up the environment.
verifyrun any checks to verify the package is valid and meets quality criteria.
installinstall the package into the local repository, for use as a dependency in other projects locally.
deploydone in an integration or release environment, copies the final package to the remote repository for sharing with other developers and projects.

Site Lifecycle

PhaseDescription
pre-siteexecute processes needed prior to the actual project site generation
sitegenerate the project’s site documentation
post-siteexecute processes needed to finalize the site generation, and to prepare for site deployment
site-deploydeploy the generated site documentation to the specified web server

Built-in Lifecycle Bindings

Some phases have goals bound to them by default. And for the default lifecycle, these bindings depend on the packaging value. Here are some of the goal-to-build-phase bindings.

Clean Lifecycle Bindings

Phaseplugin:goal
cleanclean:clean

Default Lifecycle Bindings – Packaging ejb / ejb3 / jar / par / rar / war

Phaseplugin:goal
process-resourcesresources:resources
compilecompiler:compile
process-test-resourcesresources:testResources
test-compilecompiler:testCompile
testsurefire:test
packageejb:ejb or ejb3:ejb3 or jar:jar or par:par or rar:rar or war:war
installinstall:install
deploydeploy:deploy

Default Lifecycle Bindings – Packaging ear

Phaseplugin:goal
generate-resourcesear:generate-application-xml
process-resourcesresources:resources
packageear:ear
installinstall:install
deploydeploy:deploy

Default Lifecycle Bindings – Packaging maven-plugin

Phaseplugin:goal
generate-resourcesplugin:descriptor
process-resourcesresources:resources
compilecompiler:compile
process-test-resourcesresources:testResources
test-compilecompiler:testCompile
testsurefire:test
packagejar:jar and plugin:addPluginArtifactMetadata
installinstall:install
deploydeploy:deploy

Default Lifecycle Bindings – Packaging pom

Phaseplugin:goal
package
installinstall:install
deploydeploy:deploy

Site Lifecycle Bindings

Phaseplugin:goal
sitesite:site
site-deploysite:deploy
Rajesh Kumar
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Chris
Chris
7 months ago

In the entire post you never bothered to explain what are plugins or goals.

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