Maven: The Complete Reference
The following sections detail Maven’s command line options.
To define a property use the following option on the command line:
- -D, --define <arg>
- Defines a system property
This is the option most frequently used to customized the behavior of
Maven plugins. Some examples of using the
-D command line argument:
$ mvn help:describe -Dcmd=compiler:compile $ mvn install -Dmaven.test.skip=true
Properties defined on the command line are also available as properties to be used in a Maven POM or Maven Plugin. Form more information about referencing Maven properties, see Chapter 9, Properties and Resource Filtering.
Properties can also be used to activate build profiles. For more information about Maven build profiles, see Chapter 5, Build Profiles.
To list the available command line parameters, use the following command line option:
- -h, --help
- Display help information
Executing Maven with this option produces the following output:
$ mvn --help usage: mvn [options] [<goal(s)>] [<phase(s)>] Options: -am,--also-makeIf project list is specified, also build projects required by the list -amd,--also-make-dependentsIf project list is specified, also build projects that depend on projects on the list -B,--batch-modeRun in non-interactive (batch) mode ...
If you are looking for information about the goals and parameters available from a specific Maven plugin, see Section 6.3, “Using the Maven Help Plugin”.
To activate one or more build profiles from the command line, use the following option:
- -P, --activate-profiles <arg>
- Comma-delimited list of profiles to activate
For more information about build profiles, see Chapter 5, Build Profiles.
To display Maven version information, use one of the following options on the command line:
- -V, --show-version
- Display version information WITHOUT stopping build
- -v, --version
- Display version information
Both of these options produce the same version information output, but the -v option will terminate the Maven process after printing out the version. You would use the -V option if you wanted to have the Maven version information present at the beginning of your build’s output. This can come in handy if you are running Maven in a continuous build environment and you need to know what version of Maven was used for a particular build.
Maven Version Information.
$ mvn -v Apache Maven 2.2.1 (r801777; 2009-08-06 14:16:01-0500) Java version: 1.6.0_15 Java home: /System/Library/Frameworks/JavaVM.framework/Versions/1.6.0/Home Default locale: en_US, platform encoding: MacRoman OS name: "mac os x" version: "10.6.1" arch: "x86_64" Family: "mac"
If you ever need to use Maven without having access to a network, you should use the following option to prevent any attempt to check for updates to plugins or dependencies over a network:
- -o, --offline
- Work offline
When running with the offline option enabled, Maven will not attempt to connect to a remote repository to retrieve artifacts.
If you don’t like the pom.xml file name, the location of your user-specific Maven settings, or the default location of your global settings file, you can customize any of these things with the following options:
- -f, --file <file>
- Forces the use of an alternate POM file
- -s,--settings <arg>
- Alternate path for the user settings file
- -gs, --global-settings <file>
- Alternate path for the global settings file
The following commands allow you to use Maven to encrypt passwords for storage in a Maven settings file:
- -emp, --encrypt-master-password <password>
- Encrypt master security password
- -ep, --encrypt-password <password>
- Encrypt server password
Encrypting passwords is documented in Section 15.2.11, “Encrypting Passwords in Maven Settings”.
The following options control how Maven reacts to a build failure in the middle of a multi-module project build:
- -fae, --fail-at-end
- Only fail the build afterwards; allow all non-impacted builds to continue
- -ff, --fail-fast
- Stop at first failure in reactorized builds
- -fn, --fail-never
- NEVER fail the build, regardless of project result
-fae options are useful options for multi-module
builds that are running within a continuous integration tool like
-ff option is very useful for developers running
interactive builds who want to have rapid feedback during the
If you want to control Maven’s logging level, you can use one of the following three command line options:
- -e, --errors
- Produce execution error messages
- -X, --debug
- Produce execution debug output
- -q, --quiet
- Quiet output - only show errors
-q option only prints a message to the output if there is an
error or a problem.
-X option will print an overwhelming amount of debugging log
messages to the output. This option is primarily used by Maven
developers and by Maven plugin developers to diagnose problems with
Maven code during development. This
-X option is also very useful if
you are attempting to diagnose a difficult problem with a dependency
or a classpath.
-e option will come in handy if you are a Maven developer, or if
you need to diagnose an error in a Maven plugin. If you are reporting
an unexpected problem with Maven or a Maven plugin, you will want to
pass both the
-e options to your Maven process.
To run Maven in batch mode use the following option:
- -B, --batch-mode
- Run in non-interactive (batch) mode
Batch mode is essential if you need to run Maven in a non-interactive, continuous integration environment. When running in non-interactive mode, Maven will never stop to accept input from the user. Instead, it will use sensible default values when it requires input.
The following command line options affect the way that Maven will interact with remote repositories and how it verifies downloaded artifacts:
- -C, --strict-checksums
- Fail the build if checksums don’t match
- -c, --lax-checksums
- Warn if checksums don’t match
- -U, --update-snapshots
- Forces a check for updated releases and snapshots on remote repositories
If you are concerned about security, you will want to run Maven with
-C option. Maven repositories maintain an MD5 and SHA1 checksum
for every artifact stored in a repository. Maven is configured to warn
the end-user if an artifact’s checksum doesn’t match the downloaded
artifact. Passing in the
-C option will cause Maven to fail the
build if it encounters an artifact with a bad checksum.
-U option is useful if you want to make sure that Maven is
checking for the latest versions of all SNAPSHOT dependencies.
There will be times when you simply want to run a Maven build without having Maven descend into all of a project’s submodules. You can do this by using the following command line option:
- -N, --non-recursive
- Prevents Maven from building submodules. Only builds the project contained in the current directory.
Running this will only cause Maven to execute a goal or step through
the lifecycle for the project in the current directory. Maven will not
attempt to build all of the projects in a multi-module project when
you use the
-N command line option.