List all of the possible goals in Maven 2?

I'm new to Maven, coming from the Ant world.

Is it possible to list all of the possible goals (including, say, all the plugins) that you can run?

I can see that there used to be a -g flag in Maven 1, but this isn't available in version 2.

The goal you indicate in the command line is linked to the lifecycle of Maven. For example, the build lifecycle (you also have the clean and site lifecycles which are different) is composed of the following phases:

• 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.
• integration-test: process and deploy the package if necessary into an environment where integration tests can be run.
• verify: run any checks to verify the package is valid and meets quality criteria
• install: install the package into the local repository, for use as a dependency in other projects locally.
• deploy: done in an integration or release environment, copies the final package to the remote repository for sharing with other developers and projects.

You can find the list of "core" plugins here, but there are plenty of others plugins, such as the codehaus ones, here.

> Is it possible to list all of the possible goals (including, say, all the plugins) that it is possible to run?

Maven doesn't have anything built-in for that, although the list of phases is finite (the list of plugin goals isn't since the list of plugins isn't).

But you can make things easier and leverage the power of bash completion (using cygwin if you're under Windows) as described in the Guide to Maven 2.x auto completion using BASH (but before to choose the script from this guide, read further).

To get things working, first follow this guide to setup bash completion on your computer. Then, it's time to get a script for Maven2 and:

• While you could use the one from the mini guide
• While you use an improved version attached to MNG-3928
• While you could use a random scripts found around the net (see the resources if you're curious)
• I personally use the Bash Completion script from Ludovic Claude's PPA (which is bundled into the packaged version of maven in Ubuntu) that you can download from the HEAD. It's simply the best one.

Below, here is what I get just to illustrate the result:

$ mvn [tab][tab]
Display all 377 possibilities? (y or n)
ant:ant
ant:clean
ant:help
antrun:help
antrun:run
archetype:crawl
archetype:create
archetype:create-from-project
archetype:generate
archetype:help
assembly:assembly
assembly:directory
assembly:directory-single
assembly:help
assembly:single

...

Of course, I never browse the 377 possibilities, I use completion. But this gives you an idea about the size of "a" list :)

Resources

• Guide to Maven 2.x auto completion using BASH

• Fixing Maven 2.x BASH auto completion on CYGWIN

• Maven bash completion

• maven2 bash completion complete

• Maven Tab Auto Completion in Bash

• Advanced Bash completion script for Maven 2

Strange nobody listed an actual command to do it:

mvn help:describe -e -Dplugin=site

If you want to list all goals of the site plugin. Output:

> Name: Apache Maven Site Plugin Description: The Maven Site Plugin is a > plugin that generates a site for the current project. Group Id: > org.apache.maven.plugins Artifact Id: maven-site-plugin Version: 3.7.1 > Goal Prefix: site > > This plugin has 9 goals: > > site:attach-descriptor Description: Adds the site descriptor > (site.xml) to the list of files to be > installed/deployed. > For Maven-2.x this is enabled by default only when the project has pom > packaging since it will be used by modules inheriting, but this can be > enabled for other projects packaging if needed. > This default execution has been removed from the built-in lifecycle of > Maven 3.x for pom-projects. Users that actually use those projects to > provide a common site descriptor for sub modules will need to explicitly > define this goal execution to restore the intended behavior. > > site:deploy Description: Deploys the generated site using wagon > supported protocols to > the site URL specified in the section of the POM. > For scp protocol, the website files are packaged by wagon into zip archive, > then the archive is transfered to the remote host, next it is un-archived > which is much faster than making a file by file copy. > > site:effective-site Description: Displays the effective site > descriptor as an XML for this > build, after inheritance and interpolation of site.xml, for the first > locale. > > site:help Description: Display help information on > maven-site-plugin. > Call mvn site:help -Ddetail=true -Dgoal= to display parameter > details. > > site:jar Description: Bundles the site output into a JAR so that it > can be deployed > to a repository. > > site:run Description: Starts the site up, rendering documents as > requested for > faster editing. It uses Jetty as the web server. > > site:site Description: Generates the site for a single project. > Note that links between module sites in a multi module build will not work, > since local build directory structure doesn't match deployed site. > > site:stage Description: Deploys the generated site to a local > staging or mock > directory based on the site URL specified in the > section of the POM. > It can be used to test that links between module sites in a multi-module > build work. > > This goal requires the site to already have been generated using the site > goal, such as by calling mvn site. > > site:stage-deploy Description: Deploys the generated site to a > staging or mock URL to the > site URL specified in the section of the POM, > using wagon supported protocols > > For more information, run 'mvn help:describe [...] -Ddetail'

More details on https://mkyong.com/maven/how-to-display-maven-plugin-goals-and-parameters/

If you use IntelliJ IDEA you can browse all maven goals/tasks (including plugins) in Maven Projects tab:

A Build Lifecycle is Made Up of Phases

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.

Source: https://maven.apache.org/guides/introduction/introduction-to-the-lifecycle.html

Lets make it very simple:

Maven Lifecycles:

1. Clean
2. Default (build)
3. Site

Maven Phases of the Default Lifecycle:

1. Validate
2. Compile
3. Test
4. Package
5. Verify
6. Install
7. Deploy

Note: Don't mix or get confused with maven goals with maven lifecycle.

See Maven Build Lifecycle Basics1