The Design and Performance of MedJava

The Java programming language has gained substantial popularity in the past two years. Java’s networking features, along with the growing number of Web browsers that execute Java applets, facilitate Internet programming. Despite the popularity of Java, however, there are many concerns about its efficiency. In particular, networking and computation performance are key concerns when considering the use of Java to develop performance-sensitive distributed applications. This paper makes three contributions to the study of Java for performance-sensitive distributed applications. First, we describe an architecture using Java and the Web to develop MedJava, which is a distributed electronic medical imaging system with stringent networking and computation requirements. Second, we present benchmarks of MedJava image processing and compare the results to the performance of xv, which is an equivalent image processing application written in C. Finally, we present performance benchmarks using Java as a transport interface to exchange large medical images over high-speed ATM networks. For computationally intensive algorithms, such as image filters, hand-optimized Java code, coupled with use of a JIT compiler, can sometimes compensate for the lack of compiletime optimization and yield performance commensurate with identical compiled C code. With rigorous compile-time optimizations employed, C compilers still tend to generate more efficient code. However, with the advent of highly optimizing Java compilers, it should be feasible to use Java for the This research is supported in part by a grant from Siemens Medical Engineering, Erlangen, Germany. performance-sensitive distributed applications where C and C++ are currently used.