--------------------------------------------------------------------------
To subscribe/unsubscribe to the hdfnews mailing list, please send your
request to ncsalist@ncsa.uiuc.edu with the appropriate command (e.g.
subscribe hdfnews, unsubscribe hdfnews, help) in the *body* of the message.
--------------------------------------------------------------------------


                              Newsletter #26
                              August 29, 1997

CONTENTS

NCSA HDF Java Products Release 2.0
 A. The Java HDF Viewer (JHV) Version 2.0  *******************************
      New Features and Changes             * Visit the HDF home page     *
 B. The Java HDF Interface (JHI)           * for up-to-date information  *
 C. Platforms Supported                    * on HDF:                     *
                                           *   http://hdf.ncsa.uiuc.edu/ *
                                           *******************************

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


NCSA HDF Java Products Release 2.0
==================================

The Java HDF Interface (JHI) and The Java HDF Viewer (JHV)

 The new NCSA Java products are now available.  They include both 
 the Java HDF Interface (JHI) for the HDF library and the Java-based 
 HDF Viewer (JHV) version 2.0, as well as the full source code for 
 both of these products.

 For information about the products and how to download them,
 please look at:

    http://hdf.ncsa.uiuc.edu/java-hdf-html/

 This official release is based on the Java Development Kit JDK
 1.1.


A. The Java HDF Viewer (JHV) Version 2.0

 The Java HDF Viewer version 2.0 contains significant changes from 
 the beta version (JHV 1.20b) previously released.

 Following are the new features and changes in JHV for this release:

   o It is based on JDK 1.1, and uses new features of the Java 
     environment that were not available in JDK 1.02.

   o It uses and requires the JHI, described below.

   o Palette manipulation has been made into a separate package
     (`ncsa.hdf.palette'), which may be used independently of the
     JHV or HDF library.

   o There are many internal changes and bug fixes.

 JHV 1.20b will work with JDK 1.1, but JHV 2.0 requires JDK 1.1
 or above.  The collaborative version of JHV version 2.0 is not
 available at this time.

B. The Java HDF Interface (JHI)

 The Java HDF Interface (JHI) provides an interface to essentially
 all the functions of the NCSA HDF library. The JHI is analogous
 to the FORTRAN interface already provided as part of the HDF
 library release.

 Any Java application can use the interface classes to read and
 write HDF files using the Java package `ncsa.hdf.hdflib'. This
 package ``wraps around'' the standard HDF 4.1r1 library, which is called
 from Java through `native' methods.

 Intended Use

 The JHI is not a pure Java implementation of the HDF library. The
 Java HDF interface uses the Java Native Method Interface (JNI)
 to interface to the HDF library. The interface code also uses the
 Java Core Reflection package to implement run-time type
 discovery and data conversion of arrays.

 The Java HDF interface is intended to be the foundation that
 allows Java classes to read and write HDF files. The central class
 of the `ncsa.hdf.hdflib' package is ` HDFLibrary' which has native
 methods for all the entry points of the HDF library.

 The JHI can be used by any Java application.

C. Platforms Supported

 This release has been tested and is supported on the following
 platforms:
   
   Irix 5.3
   Irix 6.2
   Solaris 2.5
   Solaris x86
   Windows NT/95

 For information on availability on different platforms, please
 see the "Availability" page in the Installation section off of
 the NCSA HDF Java Products web page: 

    http://hdf.ncsa.uiuc.edu/java-hdf-html/availability.html