More efficiently dependency management for Java packages
The way that Java dependencies are handled has changed in Fedora 21. Packages that do not interact with the X server or audio subsystem, now depend on a new OpenJDK headless subpackage. This means installation size reduction on servers, a change that aims for efficiency.
Documentation for Java packages is now optional, saving even more space on your server. Look for the -doc subpackage for Java packages to install the accompanying documentation. If you need access to API documentation of Java libraries without javadoc subpackage try using upstream web pages which should be accessible at homepage URL of the project in question. You can query for the URL of installed package with rpm -qi <package> | grep '^URL'
Java packaging guidelines now require to convert most Java packages to have "Requires: java-headless" when appropriate. Changes can be found at Fedora wiki:
Update to OpenJDK 8
OpenJDK8 is now the default Java Runtime in Fedora, replacing OpenJDK7. A full list of the features added in OpenJDK7 is available upstream at http://openjdk.java.net/projects/jdk8/features/.