J2ME Background and Resources
Background
J2ME is short for Java 2 Platform, Micro Edition. It's Java for small devices, including pagers, mobile phones, and PDAs. J2ME consists of configurations, profiles, and optional APIs. The configuration specifies a Java Virtual Machine (JVM) and a set of APIs for a group of devices. For the JavaRosa project, we are using the Connected Limited Device Configuration (CLDC) 1.1. The profile is layered on top of the configuration. It adds additional APIs for developing applications on a subset of the configuration family of devices. For the JavaRosa project, we are using the Mobile Information Device Profile (MIDP) 2.0.
Toolkits
The user interface functionality provided by MIDP 2.0 javax.microedition.lcdui package is extremely limited. For that reason, many open-source toolkits exist for creating more sophisticated J2ME GUI's.
The J2ME-Polish Toolkit
For the JavaRosa project, we are using the J2ME-Polish toolkit.
Other toolkits
We investigated a few other toolkits before choosing Polish.
API's
- The Connected Limited Device Configuration (CLDC) 1.1
- The Mobile Information Device Profile 2.0
- J2ME-Polish
Books
- Beginning J2ME From Novice to Professional (Dimagi has a copy)
- Pro J2ME Polish (Dimagi has a copy)
- MIDP 2.0 Style Guide for the Java 2 Platform, Micro Edition (Dimagi has a copy)
This book is poorly titled. It's not really a style guide. It's a usability guide, a very good one. It's a quick read and packed with practical tips for designing good mobile phone user interfaces.
Websites
Tells you which configurations, profiles, and APIs are supported by which devices.
