How do I get Java for Embedded Devices

Java for embedded devices (Java Embedded) is generally integrated by the device manufacturers. It is NOT available for download or installation by consumers. You need to check with your device manufacturer about availability of this technology in your device.
Embedded devices, or embedded systems, are specialized computer systems that constitute components of larger electromechanical systems with which they interface. These can range from the tiny chips on your office identification card or credit card, to components of very larger server class systems. Many of the sophisticated and connected devices supporting our daily activities are "embedded devices". Some common examples include SIM cards, VOIP phones, Blu-ray Disc players, televisions, utility meters, healthcare gateways, industrial controls, and countless other devices. Oracle's Java Embedded technologies provide the software development platform and runtime for billions of these embedded devices.
Developers should refer to the Oracle Technology Network (OTN) for more information about Java Embedded technologies and Oracle's Java Embedded solutions. Oracle offers a variety of Java Embedded products that allow you to develop highly functional, reliable, portable, and secure solutions for small to large embedded devices while reducing costs, improving product quality, and speeding time to market.

Defining a database

All this data needs to reside somewhere; specifically, within a database.
Databases are complex software programs that catalog and provide access to
data. Although the data is usually stored on a disk storage system, the database
software manages how that data is stored and managed.
Businesses use databases to store their data because the size and complexity
of their data often exceed what can be stored on a spreadsheet. Most business
and scientific activities, and many social activities involving technology
will require the creation, access, updating, or deleting of data at some level.
It is database software that allows these activities occur in a fast, efficient
manner.