Wireless Application Based On J2ME Platform

The Java 2 Platform,Micro Edition(J2ME) is the Java platform for consumer and embedded devices such as mobile phone, PDA, TV set-top boxes, in-vehicle telematics systems. In order to meet the complexity of the equipment field of the goal, J2ME has defined two key concepts : Configuration and Profile .They are a series of norms and standards sets which form system structure of J2ME together and guarantee the platform compatibility of Java technology. In numerous norms and standards, the platform which is consisted of CLDC (Connected, Limited Device Configuration ) and MIDP (Mobile Information Device Profile) is a prevailing J2ME platform. It already get the supports of the masses of the mobile information equipment manufacturers, service providers and developers of the application programs.The appearance of J2ME has been pouring new vigor into the applications of wireless. People can download new MIDP application programs through network which makes their mobile information equipments (mobile phone, PDA, etc.) more individual .People can also visit various kinds of services on Internet through the network application software on the equipment . By now people have pay more attentions to the wireless applications and developments of mobile information equipments. But because of the limits of the equipments of the mobile information resources, it makes more difference between the design and development of wireless application and the traditional tabletop applications.This text has developed a public transportation route system which is based on J2ME.It describles MIDP application programs and relevant technologies in detail.We developed foundational classes through the interface of agreements of HTTP that MIDP offered .They are the classes which are used in the methods for long distance services.We also used them to designand devolop the application that is the services of download of data of publictransportation route. This foundational classes have the following characteristics: Encapsulation. They encapsulate the details of HTTP agreement communications, the programmer needn't learn the principles and the methods of the interface of HTTP agreement too much and can carry on network development of MIDP quipments application programs. It can reduce the difficulty of development of the application programs of networks greatly. Independence of the platform. Development The course of the devolopment of the class only use standard MIDP API .It makes it can apply in all equipments of MIDP realized in J2ME. Using them to devolop the network programs can make programmers emphasis pn the design and realization of the service functions, and do not need to concern more communication details .Using them to devolop the network programs can make programmers emphasis pn the design and realization of the service functions, and do not need to concern more communication details. It has improved the efficiency of developing and benefited to the maintenance of the code either. Generalization.lt can devolop many remote services based on them and has wild generalization. Transparency of the service position. The remote services are designed on the basis of this classes and their positions are transparent to the clients. The programmer of the clients just know the definations of the methods in serves interfaces can invoke this method and they don't care about the right position.