Maven FAQ and code snippets for beginners
I have been using Maven with eclipse for two years and have found many simple and useful maven plugins and features like automatically downloading java sources, javadocs, running in an embedded container, importing the project to eclipse. Here’s a list of some useful code snippets and use case scenarios that I hope other maven beginners would find useful.
Download maven from apache.org
Install maven on your local machine
The simplest way to install is to download maven and unzip it in /usr/local/maven-X.X.X (where X.X.X denotes the appropriate version)
Follow this guide: http://maven.apache.org/guides/mini/guide-configuring-maven.html
Create a new java project
mvn archetype:create -DgroupId=com.mycompany.app -DartifactId=my-app
Create a new webapp project
mvn archetype:create -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-webapp -DgroupId=com.mycompany -DartifactId=my-app
Compile
Go to the top level directory which contains pom.xml. Run the following command:
mvn compile
Testing
Run unit tests
mvn test
How to make the unit tests in maven run in the integration-test phase
The following configuration:
- In maven:test phase: runs nothing
- In maven:integration-test phase: runs both unit tests, and (selenium) integration tests
<!-- let surefire plugin be executed during the integration-test phase,
the selenium server is started by that time -->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<skip>true</skip>
</configuration>
<executions>
<execution>
<phase>integration-test</phase>
<goals>
<goal>test</goal>
</goals>
<configuration>
<skip>false</skip>
</configuration>
</execution>
</executions>
</plugin>
Create a distribution
mvn package
Install
To install the generated output in the repository, run the following command:
mvn install
Install a jar into your maven repository
Adjust the following command to match your jar name, path name etc.
mvn install:install-file
-Dfile=/path/to/your/jar/your.jar
-DgroupId=org.your.group.id
-DartifactId=your-artifact-id
-Dversion=1.0.0 -Dpackaging=jar
Generating an eclipse project from a maven project
mvn eclipse:eclipse
If you app is a Dynamic Web Project, try the following option:
mvn -Dwtpversion=1.0 eclipse:eclipse
Set a default version of eclipse 1.0
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<workspace>${basedir}</workspace>
<wtpversion>1.0</wtpversion>
</configuration>
</plugin>
Set download sources option in generated eclipse project
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<configuration>
<workspace>${basedir}</workspace>
<downloadSources>true</downloadSources>
</configuration>
</plugin>
Eclipse
Install maven plugin in Eclipse
Goto Help -> Software Update -> Find and install -> Search for new Features to install -> New remote Site
Name: Maven
URL: http://m2eclipse.codehaus.org/
Import your maven project in Eclipse
# Eclipse -> File -> Import -> General -> Existing project into Workspace -> Select root directory ->
Tell eclipse your maven2 repository’s location
Goto Window -> Preferences -> Java -> build path -> classpath variable -> New
Name: M2_REPO
Path: /path/to/your/.m2/repository
Settings.xml
Reference: http://maven.apache.org/maven-settings/settings.html
Deploying to tomcat
mvn tomcat:deploy
Reference: http://mojo.codehaus.org/tomcat-maven-plugin/deployment.html
Jetty
Reference documentation here: http://docs.codehaus.org/display/JETTY/Jetty+Documentation
Installing Jetty
<plugin>
<groupId>org.mortbay.jetty</groupId>
<artifactId>maven-jetty-plugin</artifactId>
<configuration>
<jettyEnvXml>${basedir}/src/test/resources/jetty/env.xml</jettyEnvXml>
<userRealms>
<userRealm
implementation="org.mortbay.jetty.security.HashUserRealm">
<name>YourRealm</name>
<config>${basedir}/src/test/resources/jetty/security.properties</config>
</userRealm>
</userRealms>
<connectors>
<connector implementation="org.mortbay.jetty.nio.SelectChannelConnector">
<port>8080</port>
<maxIdleTime>60000</maxIdleTime>
</connector>
</connectors>
</configuration>
</plugin>
Starting jetty through cargo
<plugin>
<groupId>org.codehaus.cargo</groupId>
<artifactId>cargo-maven2-plugin</artifactId>
<version>0.3-SNAPSHOT</version>
<configuration>
<wait>false</wait>
<container>
<containerId>jetty6x</containerId>
<type>embedded</type>
</container>
<configuration>
<properties>
<cargo.servlet.port>9090</cargo.servlet.port>
</properties>
</configuration>
</configuration>
</plugin>
Sample jetty env.xml
<?xml version="1.0"?>
<!DOCTYPE Configure PUBLIC "-//Mort Bay Consulting//DTD Configure//EN" "http://jetty.mortbay.org/configure.dtd">
<Configure class="org.mortbay.jetty.webapp.WebAppContext">
<!-- Add an EnvEntry only valid for this webapp -->
<New id="gargle" class="org.mortbay.jetty.plus.naming.EnvEntry">
<Arg>gargle</Arg>
<Arg type="java.lang.Double">100</Arg>
<Arg type="boolean">true</Arg>
</New>
<!-- Add an override for a global EnvEntry -->
<New id="wiggle" class="org.mortbay.jetty.plus.naming.EnvEntry">
<Arg>wiggle</Arg>
<Arg type="java.lang.Double">55.0</Arg>
<Arg type="boolean">true</Arg>
</New>
<!-- an XADataSource -->
<New id="mydatasource99" class="org.mortbay.jetty.plus.naming.Resource">
<Arg>jdbc/mydatasource99</Arg>
<Arg>
<New class="com.atomikos.jdbc.SimpleDataSourceBean">
<Set name="xaDataSourceClassName">org.apache.derby.jdbc.EmbeddedXADataSource</Set>
<Set name="xaDataSourceProperties">databaseName=testdb99;createDatabase=create</Set>
<Set name="UniqueResourceName">mydatasource99</Set>
</New>
</Arg>
</New>
</Configure>
Sample jetty security.properties
#username: password[,rolename ...] admin:admin,admin
How to launch jetty
mvn jetty:run
Enabled Java 1.5
<plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>1.5</source> <target>1.5</target> <verbose>true</verbose> </configuration> </plugin>
Selenium
Here’s a good Maven Selenium reference page for beginners.
Installing Cargo
Add this plugin repository:
<pluginRepositories> <pluginRepository> <id>codehaus snapshot repository</id> <url>http://snapshots.repository.codehaus.org/</url> <releases> <enabled>true</enabled> </releases> </pluginRepository> </pluginRepositories>
How do I document my maven plugin
See my blog post on Documenting your Maven plugin
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