If your project already uses Maven and you want to include osmdroid then it's as simple as
<dependency>
<groupId>org.osmdroid</groupId>
<artifactId>osmdroid-android</artifactId>
<version>{VERSION}</version>
<classifier>release</classifier>
<type>aar</type>
</dependency>
If you're new to using maven with android, you'll probably want to either follow our guide.
osmdroid also has an optional library to provide addition features of 3rd party organizations.
<dependency>
<groupId>org.osmdroid</groupId>
<artifactId>osmdroid-third-party</artifactId>
<version>{VERSION}</version>
<classifier>release</classifier>
<type>aar</type>
</dependency>