The present version of DNSJava is a fork from the jdnssec-dnsjava version, found at https://github.com/dblacka/jdnssec-dnsjava, which was originally a "minor fork of DNSjava to support jdnssec-tools".
The online version of the javadoc can be found here
For example (using Maven):
<dependencies>
<dependency>
<groupId>com.discoverydns</groupId>
<artifactId>ddns-dnsjava</artifactId>
<version>1.1.8-r1685</version>
</dependency>
</dependencies>
You can view the source on GitHub/DiscoveryDNS. Contributions via pull requests are welcome.