All methods that refer to types defined in the java.awt.peer and java.awt.dnd.peer packages (the "peer types") were removed from the Java API in Java SE 9 .
Application code which calls any such method which accepts or returns a type defined in these packages will no longer link. This is a BINARY incompatible change.

Additional information is provided here:
http://mail.openjdk.java.net/pipermail/awt-dev/2015-February/008924.html