Add to your pom.xml to use Restlet 2.1.2 in a maven project.

partial-pom.xml

    <repositories>
        <repository>
            <id>maven-restlet</id>
            <name>Public online Restlet repository</name>
            <url>http://maven.restlet.org</url>
        </repository>
    </repositories>
 
    <dependencies>
        <!-- Restlet for Java Standard Edition -->
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet</artifactId>
            <version>2.1.2</version>
        </dependency>
        <!-- "HTTP engine capable of handling enormous loads" -->
        <dependency>
            <groupId>org.restlet.jse</groupId>
            <artifactId>org.restlet.ext.simple</artifactId>
            <version>2.1.2</version>
        </dependency>
    </dependencies>