Java Development on PDAs Building Applications for PocketPC and Palm

J2ME Wireless Toolkit

Sun's J2ME Wireless Toolkit (J2MEWTK) is a set of tools for developing applications for the CLDC/MIDP platform. It runs on Windows, Solaris, and Linux, and provides an emulation environment for a variety of devices. It also uses the POSE to emulate the Palm device. The J2MEWTK allows the use of any text editor for editing source files.

The Java virtual machine provided with the J2MEWTK is the KVM, a compact virtual machine targeting devices with less than a megabyte of memory. Refer to http://java.sun.com/products/cldc/wp/KVMwp.pdf for more information about the KVM.

Download the Wireless Toolkit and install it in the default installation directory.

MIDP for Palm OS

Whether or not you decide to use Sun's J2MEWTK for the IDE in your development projects, if you choose a generic MIDP development toolset then you will also need a way to convert the MIDP JAD/JAR to a PRC for the Palm device. MIDP for Palm is a free graphical tool from Sun for doing just that.^[1]

^[1] The J2MEWTK also includes this functionality, but it does not include MIDP for Palm. The J2MEWTK produces a JAD file and converts to a PRC only when the application is run with the Palm emulator. A JAD is a parameter file for defining values of predefined MIDlet parameter values, and for user-defined parameters. The MIDP for Palm converter tool allows the developer to convert any JAD/JAR pair into a PRC.

Included in the MIDP for Palm toolset:

• A utility for converting a standard MIDP JAD/JAR into a Palm PRC for downloading to the device.

• An implementation of KVM and the CLDC/MIDP libraries for the Palm.

• Some example Java applications.

MIDP for Palm takes up about 590 KB of memory and runs on devices that:

• Run Palm OS 3.5.x.

• Have at least 4 MB of total memory.

MIDP for Palm also includes an ability to capture output streams System.out and System.err.

Download the MIDP for the Palm ZIP file and unzip it into a convenient location. Install the Java runtime on the Palm by installing the MIDP.prc file from the MIDP for Palm PRCfiles directory.