maven command to create your application

How do I make my first Maven project?

We are going to jump headlong into creating your first Maven project! To create our first Maven project we are going to use Maven's archetype mechanism. An archetype is defined as an original pattern or model from which all other things of the same kind are made . In Maven, an archetype is a template of a project which is combined with some user input to produce a working Maven project that has been tailored to the user's requirements. We are going to show you how the archetype mechanism works now, but if you would like to know more about archetypes please refer to our Introduction to Archetypes .

On to creating your first project! In order to create the simplest of Maven projects, execute the following from the command line:

mvn archetype:create \
  -DarchetypeGroupId=org.apache.maven.archetypes \
  -DgroupId=com.mycompany.app \
  -DartifactId=my-app

Once you have executed this command, you will notice a few things have happened. First, you will notice that a directory named my-app has been created for the new project, and this directory contains a file named pom.xml that should look like this:

<project xmlns="http://maven.apache.org/POM/4.0.0">
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
                      http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelversion>4.0.0</modelversion>
  <groupid>com.mycompany.app</groupid>
  <artifactid>my-app</artifactid>
  <packaging>jar</packaging>
  <version>1.0-SNAPSHOT</version>
  <name>Maven Quick Start Archetype</name>
  <url>http://maven.apache.org</url>
  <dependencies>
    <dependency>
      <groupid>junit</groupid>
      <artifactid>junit</artifactid>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

pom.xml contains the Project Object Model (POM) for this project. The POM is the basic unit of work in Maven. This is important to remember because Maven is inherently project-centric in that everything revolves around the notion of a project. In short, the POM contains every important piece of information about your project and is essentially one-stop-shopping for finding anything related to your project. Understanding the POM is important and new users are encouraged to refer to the Introduction to the POM .

This is a very simple POM but still displays the key elements every POM contains, so let's walk through each of them to familiarize you with the POM essentials:

• project This is the top-level element in all Maven pom.xml files.
• modelVersion This element indicates what version of the object model this POM is using. The version of the model itself changes very infrequently but it is mandatory in order to ensure stability of use if and when the Maven developers deem it necessary to change the model.
• groupId This element indicates the unique identifier of the organization or group that created the project. The groupId is one of the key identifiers of a project and is typically based on the fully qualified domain name of your organization. For example org.apache.maven.plugins is the designated groupId for all Maven plug-ins.
• artifactId This element indicates the unique base name of the primary artifact being generated by this project. The primary artifact for a project is typically a JAR file. Secondary artifacts like source bundles also use the artifactId as part of their final name. A typical artifact produced by Maven would have the form <artifactid>-<version>.<extension> (for example, myapp-1.0.jar ).</extension></version></artifactid>
• packaging This element indicates the package type to be used by this artifact (e.g. JAR, WAR, EAR, etc.). This not only means if the artifact produced is JAR, WAR, or EAR but can also indicate a specific lifecycle to use as part of the build process. (The lifecycle is a topic we will deal with further on in the guide. For now, just keep in mind that the indicated packaging of a project can play a part in customizing the build lifecycle.) The default value for the packaging element is JAR so you do not have to specify this for most projects.
• version This element indicates the version of the artifact generated by the project. Maven goes a long way to help you with version management and you will often see the SNAPSHOT designator in a version, which indicates that a project is in a state of development. We will discuss the use of snapshots and how they work further on in this guide.
• name This element indicates the display name used for the project. This is often used in Maven's generated documentation.
• url This element indicates where the project's site can be found. This is often used in Maven's generated documentation.
• description This element provides a basic description of your project. This is often used in Maven's generated documentation.

For a complete reference of what elements are available for use in the POM please refer to our POM Reference . Now let's get back to the project at hand.

After the archetype generation of your first project you will also notice that the following directory structure has been created:

my-app
|-- pom.xml
`-- src
    |-- main
    |   `-- java
    |       `-- com
    |           `-- mycompany
    |               `-- app
    |                   `-- App.java
    `-- test
        `-- java
            `-- com
                `-- mycompany
                    `-- app
                        `-- AppTest.java

As you can see, the project created from the archetype has a POM, a source tree for your application's sources and a source tree for your test sources. This is the standard layout for Maven projects (the application sources reside in ${basedir}/src/main/java and test sources reside in ${basedir}/src/test/java , where ${basedir} represents the directory containing pom.xml ).

If you were to create a Maven project by hand this is the directory structure that we recommend using. This is a Maven convention and to learn more about it you can read our Introduction to the Standard Directory Layout .

Now that we have a POM, some application sources, and some test sources you are probably asking ...

http://maven.apache.org/guides/getting-started/index.html#How_do_I_make_my_first_Maven_project

 

如果是建一个web项目的话 需要在命令中加上 

-DarchetypeArtifactId=maven-archetype-webapp

http://today.java.net/pub/a/today/2007/03/01/building-web-applications-with-maven-2.html