Embedded Java Virtual Machine Research And Practice

Now days embedded system is playing more and more important role in the applications of computer. But the hardware and software of embedded computer system are not like those, which are regular and compatible, used by desktop pc. There are so many kinds of embedded processors and embedded operating systems. If there are some applications need to be applied widely, the developer of the applications must do the porting and implementation for every different platform, which adds a lot of difficulties to the development of applications. Being the most popular language designed for cross-platform development, Java language can make applications "write once, run everywhere", which can help engineers get away from the complicated work of development and implementation. And also, Sun Microsystems, Inc. designed the micro edition of Java technology for consume electronics and embedded devices. J2ME technology provides a uniform development platform for developers of embedded system. After analyzing the embedded system, Java technology, the components and standard of J2ME platform, this thesis do the porting ant implementation work of J2ME based on CRTOS. Firstly a brief introduction, which includes analysis of the characteristic and development trend of embedded system, was made. Then the Java technology was discussed. Secondly the thesis introduces the system structure and standard of J2ME, especially CLDC and MIDP. The porting and implementation for J2ME based on CRTOS were discussed particularly. The problems and resolution including file system, load of Java class, handling of event, native call, start of KVM, were specifically described. Testing was also made for the KVM. At last a summary was made and the lack of the KVM was given.