Google is switching from the implementation of Java in  Android, based on Apache  Harmony, to a new one based on  Oracle’s OpenJDK.
The reason for the replacement is a matter of debate  among developers and industry observers, but most agree that there are  technical benefits to the change. Still, many folks point to the Oracle vs.  Google lawsuit, and say Google is making concessions to settle the lawsuit and  head off possible future claims. Whatever the reason, Android N, the codename  for the next major version of Android, will be based on OpenJDK.
Apache Harmony is an open-source, “clean  room” implementation of Java developed by the Apache Software Foundation.  OpenJDK is Oracle’s free and open-source implementation of Java, licensed  under the GNU General Public License (GNU GPL) with a linking exception.
Oracle closed its acquisition of Sun Microsystems  in January 2010 and in August of that same year, it sued Google for copyright  and patent infringement over Google’s use of Java in Android. At issue  was the improper use of Java APIs, Oracle claimed. However, Google argued that  APIs could not be copyrighted and eventually won its case in a 2012 jury verdict. Yet, in 2014 another  court partially reversed the prior ruling to  side with Oracle. The case is ongoing and the legal battle rages on -- as does  the fight over developer mindshare.
Indeed, Java 8 brought with it enhanced developer  productivity and significant application performance increases through reduced  boilerplate code, improved collections and annotations, simpler parallel  programming models and more efficient use of modern, multicore processors.  Thus, the move to OpenJDK brings Java 8 support and also simplifies the Android  code by providing a common code base for development.
