We are all clearly the upper layer of CLDC is MIDP, providing support for user interface in MIDP, we can develop the API provided in the javax.microedition.lcdui package, but there is a class of devices that do not have a display, such as NIC, router and tracker, etc. In order to meet the market needs of the above equipment, SIEMENS leaders in JCP organizations developed JSR195 Infomation Module Profile. This article will be more detailed in detail the IMP.
IMP is a strict subset of MIDP 1.0, because IMP's target devices are unable to display power and user input capabilities, the javax.microedition.lcdui package is not included there, if you want to have a device with a display and keyboard If you develop, please select MIDP1.0 or MIDP2.0.
First we understand the minimum requirements for the hardware layer: Memory: 1.128K Non-volatile memory space For IMP Components 2.8K non-volatile memory space for applications for persistent data storage 3.32K volatile memory space For Java Operation Environment (HEAP) networking capabilities: duplex, wireless, bandwidth limited
According to the basic and market demand of the above hardware, support is provided in the software layer IMP to Timer, Network and Persistent Data Storage. Since IMP is a subset of MIDP 1.0, these features are very similar to MIDP, which is not described, and you can download specific IMP specifications from JCP to find specific situations. In order to better understand the IMP system architecture, give the following frame map
The name of the application based on CLCD and IMP is imlets, in fact, he also expands javax.microedition.midlet.midlet. Therefore they have similar life cycles. Several iMlets can also pack into an IMlet kit, we also need to provide JAD files to describe the application's information, but must pay attention to the point because iMlets are IMP-based, not MIDP's microEditon-Profile property. The value should write IMP-1.0, which we should get IMP-1.0 instead of MIDP1.0 in the application through System.GetProperty ("microEditon.profile").
