At JavaOne 2011, Terrence Barr, Senior Technologist, Mobile & Embedded, Oracle Germany, presided over a two-hour HOL (Hands-On-Lab) on Monday in which he taught developers how to build an embedded Java solution that senses and controls the environment, stores data, and connects to back-end databases for synchronization and further processing. The session offered considerable detail along with step-by-step exercises as participants learned how to create the embedded EnviroTracker system and application which tracks and processes environmental data. The application interfaces with a microcontroller to read sensor input (ambient light brightness), to control output (and LED), and then further processes the sensor data.

The lab focused on:
• The benefits of Java technology in the embedded space
• The components of embedded Java platforms
• Setting up an embedded Java platform
• Interfacing between the embedded Java platform, the microcontroller, and I/O
• Accessing and controlling I/O from Java
• Processing sensor data

Barr took developers through seven basic tasks or exercises:

1. Create the EnviroTracker
2. Install the OJEC (Oracle Java ME Embedded Client) on the Development Host
The Oracle Java Micro Edition Embedded Client (OJEC) implements the CDC Platform configuration.
3. Develop and Test Your First Embedded Java Application..
4. Install OJEC on the Target Platform and Run Your Java Application
5: Understand I/O and the Arduino Microcontroller
6: EnviroTracker V1: First Contact
7: EnviroTracker V2: Continuous Monitoring and Processing

By the end of a rigorous and demanding, but satisfying two hours, attendees had built a real-world embedded system and created the EnviroTracker Application to track environmental sensor data. They learned how to install and use embedded Java runtimes and tools, and how to interface with I/O devices and microcontrollers from Java applications.

The take home message: Creating sophisticated embedded Java systems and applications is easy due to the platform independence of the Java language and runtime, the scalability of pre-existing Java skills to embedded development, and the comprehensive support provided by mature and feature-rich developer tools.

For more info, go to Terrence Barr's blog.

A new article on otn/java, “Templating with JSF 2.0 Facelets,” by Deepak Vohra, offers a concise explanation of how to use Facelets, which in JavaServer Faces (JSF) 2.0, has replaced JavaServer Pages (JSP) as the default view declaration language (VDL). With Facelets, developers no longer need to configure a view handler as they once did in JSF 1.2.

From the article itself:

“Facelets is a templating framework similar to Tiles. The advantage of Facelets over Tiles is that JSF UIComponents are pre-integrated with Facelets, and Facelets does not require a Facelets configuration file, unlike Tiles, which requires a Tiles configuration file.

JSF Validators and Converters may be added to Facelets. Facelets provides a complete expression language (EL) and JavaServer Pages Standard Tag Library (JSTL) support. Templating, re-use, and ease of development are some of the advantages of using Facelets in a Web application.

In this article, we develop a Facelets Web application in Oracle Enterprise Pack for Eclipse 11g and deploy the application to Oracle WebLogic Server 11g. In the Facelets application, an input text UIComponent will be added to an input Facelets page. With JSF navigation, the input Facelets page is navigated to another Facelets page, which displays the JSF data table generated from the SQL query specified in the input Facelets page. We will use Oracle Database 11g Express Edition for the data source. Templating is demonstrated by including graphics for the header and the footer in the input and the output; the graphics have to be specified only once in the template.”

Read the complete article here.