Oracle have announced a free 6 week training course titled 'Develop Java Applications Using a Raspberry Pi' starting on March 31st. 4-6 hours of material will be released every week and since the course contains prerecorded sessions, it can viewed anytime.
See the link for full details: https://blogs.oracle.com/java/entry/develop_java_applications_using_a
The Oracle Learning Library has created this course which provides code, examples, and experts to teach you and answer your questions.
Java experts Stephen Chin, Jim Weaver, Simon Ritter, Angela Caicedo, and Tom McGinn will lead you through basic exercises. Each week, you'll get a new set of course materials:
•A series of short, pre-recorded videos provide the "lecture" portion of the course.
•A homework project is linked to the video material, and applies what you have learned by working with Java ME Embedded, the Raspberry Pi, and some electronic components.
•A graded quiz evaluates how well you have grasped the materials and the homework.