Implementation Of Java Calls File System Based On Personal Computer

With the continuous development of the Internet and World Wide Web technology, java language has been developed rapidly as a network programming language. And has been widely used in different devices, computers and networks. Meanwhile, java as an object-oriented programming language, by virtue of their cross-platform and portability, can been used in application development especially. However, java can not achieve all functions, such as some databases and programs compiled in other languages, some characteristics which java language does not support and depend on operating system, some time-sensitive codes interact with the lower level system. This when it is necessary to introduce the JNI technology.Through the overall analysis of system architecture, system architecture is divided into three layers, which is based on the concept of SOA with Three-tier Architecture(demand layer, semantic layer, service layer). The hardware layer matches with the five interface functions in the lower level system. The system layer corresponds to the process of the file system, which is responsible for passing parameters and data associated with drive between the user layer and the hardware layer.When the user level requests for an application, the requirements mapped to file system operation processes. This article is in the WINDOWS operating system platform, based on a c code about FATFS file system, java achieves file system functions based on JNI technology. Firstly, driver functions compiled in c are taken as the atomic component of system, which include six functions:disk_initialize(), disk_status(), disk_read(),disk_write(), disk_ioctl(), get_fattime().These functions can complete the accordance of the file system layer and the hardware layer, so as to realize the function of the basic building blocks of the file system layer. User levels meet the application requirements by calling the applied semantic process.Firstly, the basic component of the file system was analyzed. Subsequently, FATFS file system has been portable to PC, based on SOA architecture. Finally, DLL (WINDOWS platform is in the form of a DLL file, UNIXS platform is in the form of a SO file) is generated based platform is in the form of a SO file) is generated based on native c code, combining of file system semantics of process and JNI technology. Because java is characterized by its cross-platform, the WINDOWS platform can achieve java calls functions of file system function by calling a DLL file (or SO file).The design makes use of eclipse development tools. On the basis of analysis of the eclipse platform architecture, the paper analyses the installation and use of eclipse plug-ins. Finally, java calls some of the functions of the file system has been achieved in PC through java and C environment configuration in eclipse environment and JNI technology. These functions include read file, write file, read file system information, read the file directory, modify file attributes,create folder,rename a file.