NCSA HDF Java Products:

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


Version 2.1 of the HDF Java Products is released as part of the Release 4.1r2 of the HDF library. The Java products are optional; the HDF library may be built and used without any Java support.

The NCSA HDF Java products include both the Java HDF Interface (JHI) for the HDF library and the Java-based HDF Viewer (JHV), Version 2.1.

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

This release depends on HDF 4.1r2. Please use the current version of the HDF library.

Changes from Release 2.0

There have been many changes in the Java products. See the Release Notes.

The Java HDF products have two parts:

  • The Java HDF Interface (JHI), a complete Java interface to the HDF 4.1r2 library. (The Java package `ncsa.hdf.hdflib'). The JHI may be used by any Java application that needs to access HDF files.
  • Version 2.1 of the JHV. The JHV 2.1 uses and requires the JHI.
This release includes full source to all the Java classes and C interface libraries, for both the JHI and the JHV.

The Java HDF Viewer (JHV), Version 2.1

The Java HDF Viewer (JHV) is a Java-based visualization tool for browsing NCSA Hierarchical Data Format (HDF) files. Opening an HDF file with the JHV lets you see all hierarchical components of any HDF file, and then view the data stored in each component. The JHV allows you to view the following HDF data objects: Scientific Datasets (up to 3 dimensions), Raster Images, Palettes, Vdata Tables, Vgroups, Attributes, and Annotations. The major features of the current JHV include: (i) Displaying file annotations and data attributes, (ii) Previewing large images and subsetting image area, (iii) Editing 2-D images and viewing image data or pixel values, (iv) Doing image animation for 8-bit raster images and 3-D data, (v) Making transparent images and overlaying 8-bit raster images, (vi) Creating spreadsheets from vdata tables or raster images, (vii) Showing distributions of image data or pixel values.

Version 2.1 of the JHV includes new features and bug fixes. See the Release Notes.

  1. New Animation features
  2. Layering of images
  3. Display of pixel or data values
  4. Color Palettes improvements

The Java HDF Interface (JHI)

The Java HDF Interface (JHI) provides an interface to essentially all the functions of the NCSA HDF 4.1r2 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'' the standard HDF 4.1r2 library, which is called from Java through `native' methods.

The JHV Version 2.1 uses the Java HDF Interface JHI. The JHI does not depend on the JHV, however. The JHI can be used by any Java application.


NCSA
HDF Group

hdfhelp@ncsa.uiuc.edu
Date modified: 17 March 1998