Hi, I will try to start with a brief and simple description of Java card applet development process.
First, you will write code of the new applet. Then the code is compiled to .class file(s). After that the .class files are converted into .cap file. Cap format is used as a container for applet that will be loaded to card (and during the conversion several security checks of code are done). Class or .cap files can be run in card simulator (JCWDE for class or CREF for .cap).
Convertor and simulator tool are included in Java Card Development kit. For compliling is used normal javac.
Now you have converted applet prepared for the loading to the card. This process follows Open/Global platform specification and it must be performed by tools that are not included in Java Card Development kit. Such tool is gpshell, for instance, or Java Card manager plug-in.
So by this plug-in you can get the .cap file of applet to the card. Or delete loaded applet on the card... Or communicate with applet on the card or simulator via APDU manager component. This plug-in does nothing with applet creation.
For applet development I can recommend this tutorials:
An Introduction to Java Card Technology
Writing a Java Card Applet/
or book Java Card Technology for Smart Cards by Zhiqun Chen
or topic on java.sun.com forums.
As I've written in owner's notes I made a plug-in that helps with applet creation. It is not finished, has some unfinished parts (for example, cannot convert with use of different export files than those from Java Card Development kit).
You can download this plug-in (Java Card Project type) here. Java Card Manager 1.4 is needed as dependency. With latest NetBeans 6.1 the plug-in should be installed correctly.
After installing of this plug-in 'New Project' dialog will contain Java Card Project type.
During the process of creation of the project you can set several applet and Java Card settings (as well as via Java Card Project Properties menu item in project context menu /right-click on project name in Project tab/). These settings are applet/package AID and name and paths to Java Card Development kit. If you use 'Browse...' button from 'Java Card API Location' item to locate file with Java Card platform API (api.jar, api21.jar,... differs for different versions of Java Card Development kit), the plug-in will try to fill other three paths.
With new project a skeleton code of Java Card applet is created. You can compile this code (normal build), convert class files through 'Convert' menu item from project's context menu and run compiled applet in JCWDE simulator via 'Run in JCWDE' menu item from project's context menu. The plug-in uses tools from Java Card Development kit.
For example, with this plug-in you can create applet code, compile it, run it in simulator and by Java Card manager plug-in you can connect to the running simulator and send applet some commands.