Java(TM) Applications Using NCSA HDF Files

HDF is a library and le format for storing and exchanging scientiic data. In the absence of a Java(TM) implementation of the HDF library, Java applications that need to directly access data in HDF les require a Java interface to the native code HDF library. This document describes the design of the Java interface for the HDF library and one prototype application, the Java HDF Viewer (JHV). Performance issues discussed in this paper appear to be inevitable consequences of the technologies that provide the portability and security of Java. The performance penalties are not signiicant for many applications, but become very signiicant for data intensive computing. Just In Time compiler technology will probably have little impact on the data copying and memory management issues described in this paper.