Maven 2

Added by Matt Raible, last edited by Matt Raible on Aug 28, 2007 23:25 Labels:  maven, ant Add Labels   Enter labels to add to this page: Tip: Looking for a label? Just start typing.

Knowledge of Maven is not required to use AppFuse because the tutorials explain how to use it. If you're interested in learning Maven in-depth, please download the book Better Builds with Maven or Maven: The Definitive Guide (zip). Both books are free - the first requires registration, the second is available without registration.

For a brief introduction to Maven see Building Web Applications with Maven 2 or The Maven 2 POM demystified. Other articles are available from the Articles on Maven page.

See Maven Plugins for information on plugins used in AppFuse.

Below is a list of commonly-used helpful Maven commands.

Command	Description
mvn clean	Deletes all files in target directory or directories (for multi-module projects)
mvn jetty:run-war	Packages and deploys your application to Jetty, reachable at http://localhost:8080
mvn -Dcargo.wait=true	Packages and deploys your application to active Cargo profile (Tomcat 5.5.x by default), reachable at http://localhost:8080/yourapp-version
mvn test	Runs all tests in src/test/java. Use "-Dtest=ClassName" (not fully-qualified) to run individual tests.
	Use -Dsurefire.useFile=false if you want to see test failures in your console (like Ant) and -Dmaven.surefire.debug if you want to open a debugger on port 5005 w/ suspend=y.
mvn package	Creates a WAR or JAR depending on your project type
mvn integration-test	Runs UI tests in Tomcat using Cargo
mvn install	Installs generated artifacts in your local repository
mvn site	Creates project site and reports
mvn -U	Checks for updated plugins and downloads if they exist
mvn -o	Work offline
mvn --help	See full list of optional commands

Ant vs. Maven

If you used AppFuse 1.x in the past and have taken the time to memorize its useful Ant commands, the following table should help you convert to using Maven.

Installing a local Maven Repository

If you're using Maven 2 in your organization on multiple projects, it's often a good idea to setup a local Maven repository on your intranet. There's a few different strategies for doing this:

• Artifactory - a Maven2 proxy repository based on JSR-170. Started with maven-proxy's codebase. See Setting up a Maven repository with Artifactory for installation instructions.
• Dead Simple Maven Proxy - DSMP is a proxy. It can be used as a repository server but it's main purposs it to act as a filter when Maven accesses the internet. If you need a repository server, use Archiva.
• Maven Archiva - still under development.
• Maven Proxy - See Sanjiv's blog entry titled Using maven-proxy to setup an internal maven repository for more information.
• Proximity - Proximity functions somewhere between http-proxy and proactive-mirror. One of its primary uses is as Java web application to serve as a Maven proxy on your company's intranet.

Troubleshooting and other Tips

The tips below are copied from Mule's Tips and Tricks with Maven 2.x. Thanks guys.

OutOfMemoryError If you are getting OutOfMemoryError exceptions when attempting a full build of Mule you may try increasing the max heap and the PermGen space sizes. Either export a MAVEN_OPTS variable in your shell or add it to the original mvn script. The following settings were confirmed working fine with Mule: MAVEN_OPTS=-Xmx512m -XX:MaxPermSize=256m

Offline option If you know your downloads are up-to-date, you can use the offline option which may speed up your build considerably depending on network latency: mvn -o

Debug option Transitive dependencies in m2 are both a blessing and a curse. The debug option is especially helpful when you find yourself in "classloader hell" (conflicting library versions or unwanted libraries are in your classpath). Among other things, it prints out the effective classpath in a tree format which makes it easy to see where each libraries is coming from. mvn -X

Non-recursive option Executing a Maven goal for a module will by default execute the goal for any modules below it in the hierarchy. If you specifically wish to run the goal for this module only (and not its children) you can use the non-recursive option. mvn -N

Debugging test failures Surefire, which is the default Maven test runner now, outputs all reports as a set of xml and text files. Any test failure details and stacktraces end up in those files, and not the console. The output can be redirected to the console temporarily by adding the following option mvn -Dsurefire.useFile=false This option will skip creating the text report, but the xml one will still be available for transformation by tools.