Maven installation is an easy and straightforward process. This chapter will explain how to install and set up Maven using the Windows 7 operating system. You can follow the same procedure with other operating systems.

You will begin the installation process by downloading the latest version of Maven from the Apache Maven web site (http://maven.apache.org/download.html). At the time of this writing, the latest version is 3.2.3. Download the Maven 3.2.3 binary .zip file as shown in Figure 2-1.

Once the download is complete, unzip the distribution to a local directory on your computer. It will create a folder named apache-maven-3.2.3-bin. This book assumes that you have placed the contents of apache-maven-3.2.3-bin folder under c: oolsmaven directory, as shown in Figure 2-2.

The next step in the installation process is to add the M2_HOME environment variable pointing to the Maven installation directory, in our case c: oolsmaven. Launch the Start menu, and right-click the Computer option. Next select System Properties followed by the Advanced system settings. This will launch the window shown in Figure 2-3.

Click the Environment Variables button, and then click New under System variables. Enter the values shown in Figure 2-4 and click OK.

The final step in the process is to modify the Path Environment variable so that you can run Maven commands from the command line. Select the Path variable and click Edit. Add %M2_HOME%/bin at the beginning of the path value, as shown in Figure 2-5. Click OK. This completes the Maven installation. If you have any open command-line windows, close them and reopen a new command-line window. When environment variables are added or modified, new values are not propagated to open command-line windows automatically.

Testing Installation

Now that Maven is installed, it’s time to test and verify the installation. Open a Command Prompt and run the following command:

mvn –v

This command should output information similar to the following:

C:WindowsSystem32>mvn -v
Apache Maven 3.2.3 (33f8c3e1027c3ddde99d3cdebad2656a31e8fdf4; 2014-08-11T14:58:10-06:00)
Maven home: c:	oolsmaven
Java version: 1.7.0_25, vendor: Oracle Corporation
Java home: C:Javajdk1.7.0_25jre
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 7", version: "6.1", arch: "x86", family: "windows"

The –v command-line option tells the path where Maven is installed and what Java version it is using. You would also get the same results by running the expanded command mvn --version.

Getting Help

You can get a list of Maven’s command-line options by using the –h or --help options. Running the command below will produce output similar to that shown in Figure 2-6.

mvn -h

Additional Settings

The installation steps we have provided so far are enough to get you started with Maven. However, for most enterprise uses, you need to provide additional configuration information. This user-specific configuration is provided in a settings.xml file located in the c:Users<<user_name>>.m2 folder.

Out of the box, the .m2 folder does not contain a settings.xml file. In the .m2 folder on your local computer, create a settings.xml file and copy the contents of the skeleton settings.xml file as shown in Listing 2-1. We will cover some of these elements in the coming chapters. A brief description of the elements is provided in Table 2-1.

Listing 2-1. Skeleton Settings.xml Contents

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                          http://maven.apache.org/xsd/settings-1.0.0.xsd">
      <localRepository/>
      <interactiveMode/>
      <usePluginRegistry/>
      <offline/>
      <pluginGroups/>
      <servers/>
      <mirrors/>
      <proxies/>
      <profiles/>
      <activeProfiles/>
</settings>

Setting Up a Proxy

As we will discuss in detail in Chapter 3, Maven requires an Internet connection to download plug-ins and dependencies. Some companies employ HTTP proxies to restrict access to the Internet. In those scenarios, running Maven will result in Unable to download artifact errors. To address this, edit the settings.xml file and add the proxy information specific to your company. A sample configuration is shown in Listing 2-2.

Listing 2-2. Settings.xml with Proxy content

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
                      http://maven.apache.org/xsd/settings-1.0.0.xsd">
  <proxies>
    <proxy>
      <id>companyProxy</id>
      <active>true</active>
      <protocol>http</protocol>
      <host>proxy.company.com</host>
      <port>8080</port>
      <username>proxyusername</username>
      <password>proxypassword</password>
      <nonProxyHosts />
    </proxy>
  </proxies>
 </settings>

IDE Support

Throughout this book, we will be using the command line to create and build sample applications. If you are interested in using an IDE, the good news is that all modern IDEs come with full Maven integration without needing any further configuration.

Summary

This chapter walked you through the setup of Maven on your local computer. You learned that Maven downloads the plug-ins and artifacts needed for its operation. These artifacts are stored in the .m2 epository folder. The .m2 folder also contains the settings.xml file, which can be used to configure Maven’s behavior.

In the next chapter, we will take a deeper look at Maven’s dependency management.