Analysis And Design Of The Jcvm Interpreter

With the progress of society and the continuous development of basic theory, the science and technology are promoted to innovate constantly, meanwhile the generation cycle of technology products are getting shorter. Since the birth of smart card technology, the smart card has been covering every aspect of our lives, and the annual market demand continues to rise. Each smart card chip always binds with specific business in a long period of time, which means high demand and cost. At the same time based on considerations of the market, Sun imported Java technology into the field of smart cards, solved the problems of high issued cost and function of oneness, which with multi applications, and quickly occupied the market. Without a doubt, Java smart card technology will be an important direction of development no matter now or in the future. Java smart card is embedded the Java Virtual Machine in COS (Chip Operation System), which provide safe and reliable operating environment for smart card applications, and also determines the Java smart card applications in the future market prospects. The related technology has become more mature in Europe and the United States because of their earlier development, and strictly blockade for others. Domestic Smart card operators introduce the technology largely through the payment of royalties, although domestic constantly pursued in recent years but still relatively backward. It has seriously restricted China’s rapid development of social economy. Consequently, the significance of researching and developing smart card technology with independent intellectual property rights is far-reaching. As people growing dependent on smart card, the sensitive information that user stored in the smart card is more and more, and at the same time suffering more serious security threat, so the foreign research organizations paid more attention to safety research in recent years.In Java smart card technology system, the most critical part is the design of virtual machine. As a core part of the virtual machine, the interpreter that with a highly complex is difficult to achieve. This topic was able to go with a swing, thanks to the previous large number of research and technology accumulation. This paper, firstly, introduced the virtual machine communication mode as well as the development process of application program, analyzed the file structure of application combined with parsing requirement, and researched the static resolution process before the interpreter to execute and run-time dynamic resolution based on the technical specifications and related information. On the basis of analyzing application program interface, the design model and the analysis progress of the virtual machine were put forward. Secondly, in order to reduce the effect of the delay of read and write that COS file system hierarchical node has brought in, and convenient for virtual machine to read data, the system adopts independent data management. This paper also analyzed and designed the application image storage structure in detail, and stated interpreter’s control management mechanism of the memory data, other key technologies and the integral model construction for applet. In the implementation of the framework, this paper, still, analyzed and designed the state control of the applet execution process, and another design feature is that the frame and context will be managed by sequential index, which simplified the complexity of the structure of the system, improved the efficiency of the system. The exception structure information is given for system exception handling mechanism; meanwhile the implementation of design is put forward based on the analysis. In the aspect of system atom handling, according to the special requirements of the chip ROM space erase, a backup and recovery mechanism is designed based on the unit of block. Aiming at the data access mechanism in the system, firewall-based security mechanisms is designed, and make a detailed analysis and elaboration of its structure design. Once more, given a brief introduction to instruction system, and makes an appropriate classification based on command functions and features, then accordance with the above construct foundation combined with the technical specifications, this paper gives out the implementation of the instruction in the form of pseudo-code. Finally, based on the sample provided by the Sun Corporation, designed the black box testing program in detail to verify the correctness of the system design, and the results show that the corresponding technical indicators are limited in the effective range.Based on the Summary of full text, Analyzed some problems of the system that still existing at present and some content of the system that need to further research.