Command-line Options

An overview of the options available while executing maven commands.

Different Command line Options

• -D: Specifies system properties or project properties.

mvn clean install -DskipTests

• -P: Activates one or more Maven profiles during the build process.

mvn clean install -Pproduction

• -X: Enables debug mode, providing detailed debugging output during the build process. It's helpful for diagnosing build issues or understanding the build process.

mvn clean install -X

• -e: Enables error output, displaying stack traces for errors that occur during the build process. It's useful for identifying and troubleshooting build failures.

mvn clean install -e

• -U: Forces Maven to check for updated dependencies and plugins from remote repositories, even if the local cache is up to date

mvn clean install -U

• -f: Specifies an alternate location for the POM file. It allows you to execute Maven commands in a directory without a POM or with a non-standard POM filename.

mvn clean install -f /path/to/alternate/pom.xml

• -pl: Specifies a comma-separated list of modules to build. It allows you to selectively build specific modules in a multi-module project.

mvn clean install -pl module1,module2

Chaining Phases

Multiple phases can be chained using spaces in a single command. This executes each phase sequentially.

mvn clean compile test package verify install

In Maven, when resolving dependencies, the order in which repositories are checked depends on the order they are defined in the pom.xml file. By default the sequence is:

1. Local Repository: Maven first looks into the local repository, which is usually located in the home directory (~/.m2/repository on Unix-like systems, or %USERPROFILE%\.m2\repository on Windows). If the required dependencies are found there, Maven uses them directly without further processing.

2. Remote Repositories: If the dependencies are not found in the local repository, Maven checks any remote repositories configured in the pom.xml file. These remote repositories could be the organization's internal repositories or other external repositories besides Maven Central. Maven checks them in the order they are defined in the pom.xml.

3. Maven Central: If the dependencies are not found in any of the configured repositories, Maven then checks Maven Central, which is the default central repository for open-source Java libraries.

Skipping phases:

• To skip a specific phase (-Dmaven.<phase>.skip=true).

mvn clean install -Dmaven.test.skip=true

• To skip both test and site phases

mvn clean install -DskipTests

-DskipTests only skips the test execution, but -Dmaven.test.skip=true will skip the compilation of test classes as well

• To skip only integration tests

mvn clean install -DskipFailsafeTests