This step will install and use Maven to build a simple Java project to ensure that the tool is configured appropriately. The first time it runs, it will cache many Jars from Central into a folder ${user.home}/.m2/repository; for subsequent runs, it will be much faster.
- Go to http://maven.apache.org/ and download the latest Maven
zip(Windows) or Maventgz(for macOS/Linux). - Unzip/untar the install into a convenient directory, referred to in these instructions as
MAVEN_HOME. - Either add
MAVEN_HOME/binto thePATHor specify the full path to the Maven executable; runmvn –version, and a version message should be printed out. Maven requires a JDK (not just a JRE), which should be installed by following the instructions from the Java site. - Run
mvn archetype:generate -DarchetypeGroupId=org.apache.maven.archetypes -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.1(all on one line) to create a new Maven project.
- When prompted for the
groupId, entercom.packtpub.e4. - When prompted for the
artifactId, entercom.packtpub.e4.tycho. - When prompted for the version and package, press Enter to take the defaults of
1.0-SNAPSHOTandcom.packtpub.e4respectively. - Finally, press Enter to create the project:
Define value for property 'groupId': com.packtpub.e4 Define value for property 'artifactId': com.packtpub.e4.tycho Define value for property 'version': 1.0-SNAPSHOT Define value for property 'package': com.packtpub.e4 Confirm properties configuration: groupId: com.packtpub.e4 artifactId: com.packtpub.e4.tycho version: 1.0-SNAPSHOT package: com.packtpub.e4 Y: : Y
- Change into the
com.packtpub.e4.tychodirectory created and runmvn packageto run the tests and create the package:[INFO] Scanning for projects... [INFO] [INFO] Building com.packtpub.e4.tycho 1.0-SNAPSHOT[INFO] T E S T S Running com.packtpub.e4.AppTest Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 0.009 sec Results : Tests run: 1, Failures: 0, Errors: 0, Skipped: 0 [INFO] Building jar: com.packtpub.e4.tycho-1.0-SNAPSHOT.jar [INFO] [INFO] BUILD SUCCESS [INFO] [INFO] Total time: 1.977s [INFO] Final Memory: 15M/136M
The Maven launcher knows how to connect to the Central repository and download additional plug-ins. When it initially launches, it will download a set of plug-ins, which in turn have dependencies on other Jars that will be resolved automatically prior to the project building.
Fortunately, these are cached in the local Maven repository (which defaults to ${user.home}/.m2/repository), so this is done only once. The repository can be cleaned or removed; the next time Maven runs, it will download any required plug-ins again.
When mvn archetype:generate is executed, a sample Java project is created. This creates a pom.xml file with the groupId, artifactId and version given and sets it up for a Java project.
When mvn package is executed, the operation depends on the packaging type of the project. This will default to jar if not specified, and the default package operation for jar is to run the compile, then run test, and finally create the Jar file of the package.
The Maven quickstart archetype is a useful way of creating a pom.xml file with known good values, and a way of verifying connectivity to the outside before moving ahead with the Eclipse-specific Tycho builds. If there's a problem with these steps, check out the troubleshooting guides at http://maven.apache.org/users/ for assistance.