Installation Guide

Java TM Web Start

Version 1.0.1_02

This installation guide provides documentation for the system requirements and installation instructions for this release of the Java TM Web Start software.

Table of Contents

System Requirements
Installing on Microsoft Windows Platforms
Installing on the Solaris TM Operating Environment and Linux

Using Java Web Start Technology with Netscape TM 6 Web Browsers
Adding a New Java Runtime Environment
Troubleshooting the Installation

System Requirements

This release of Java Web Start software has been tested following systems and with the indicated versions of the Java runtime environment ("RE"):
  • Windows 95/98/NT/2000/ME/XP using the Java RE versions 1.2.2, 1.3.0, 1.3.1, and 1.4.0
  • Solaris TM 2.6, 7, 8 Operating Environments using Java RE versions 1.2.2, 1.3.0, 1.3.1, and 1.4
  • Linux (Red Hat 6.2 and 7.1 on x86) using Java RE versions 1.2.2, 1.3.0, 1.3.1, and 1.4.0
The platform requirements for using Java Web Start software are the same as recommended for Java RE implementations.

Installing on Microsoft Windows Platforms

Launch the installer by double-clicking on the file you downloaded. The installer will guide you through the installation.

The installer looks in the Windows Registry for already installed Java REs version 1.2.2 and higher and automatically configures the Java Web Start software to use them. If you have chosen to download the installation bundle that contains the Java runtime environment, the installer will also install Java Runtime Environment 1.3.1_01 if it is not already present.

The installation registers the file extension .jnlp and the MIME type application/x-java-jnlp-file with Windows, so Java Web Start will be launched from both Netscape Navigator and Internet Explorer browsers when a link to a JNLP file is activated. The installer also installs shortcuts to the Application Manager on the desktop and in the Windows Start menu.

Installing on the Solaris TM Operating Environment and Linux

For the Solaris Operating Environment and Linux, the Java Web Start software is delivered as a ZIP file. The ZIP file contains the installation script,, along with the readme.html file. The installation script is a sh shell script for the Solaris Operating Environment, and a bash shell script for Linux. The bundle does not come with a Java runtime environment, and a Java runtime environment must be pre-installed on your system.

In order to use Java Web Start software you must have a version of Java 2 SDK, Standard Edition or Java runtime environment installed. If you do not, you can download one from here.

Place the zip file in the directory in which you want to install the Java Web Start software. Unzip the file and run the file. After you agree to the terms of the license it displays, the script will prompt you for the location of a Java runtime environment if it doesn't find one in the default location of /usr/local/java.

The installer will create the javaws subdirectory and installs all the Java Web Start files into it.

The installer also updates the .mailcap and .mime.types files, so Java Web Start software will be invoked when the Netscape Navigator browser encounters a link to a JNLP link.

Make sure to restart the Netscape browser to ensure that it picks up the new MIME type.

Using Java Web Start Technology with Netscape TM 6 Web Browsers

For users of Netscape 6 web browsers, please set up the Java Web Start MIME type (JNLP) in the Edit->Preferences->Navigator->Helper Applications section. The file extension is "jnlp", MIME Type is "application/x-java-jnlp-file", and it should be handle by the javaws executable file in your Java Web Start software directory.

Also note that you must use the non-JavaScript-technology version of the demos page, due to a problem with using JavaScript technology with some Netscape 6 browsers. For more information please refer to the developer's guide.

Adding a New Java Runtime Environment

The Microsoft Windows version of the Java Web Start product is available bundled with the Java Runtime Environment 1.3.1_01. If you install this bundle, Java RE 1.3.1_01 will be available to applications launched with Java Web Start. On the Solaris Operating Environment and Linux, the installer prompts for the location of a Java RE.

It is possible to associate new Java REs with the Java Web Start software by using the File -> Preference Panel in the built-in Application Manager. The Launching from the built-in Application Manager section describes how to launch the Application Manager.

In the Preference Panel, select the Java tab. This tab lists all the current associated Java REs that are available for an application to be launched on. The easiest way to add a new Java RE is to click on the Find... button, which opens up a Wizard that allows you to search the harddisk for already installed JREs.

In the second pane, either:

  • Type the search path in the file chooser dialog and press enter, instead of clicking on the next button, or
  • Make sure to select a directory before clicking the next button.
This will guarantee that the search starts at the given directory.

Troubleshooting the Installation

If you get a " Bad installation" error message, then the Java Web Start software has not been configured with the right information about your Java RE locations. Check the contents of the javaws.cfg file. It will be in the installation directory of Java Web Start (typically at C:\Program Files\Java Web Start\javaws.cfg on Microsoft Windows).

These configuration entries need to reflect the locations of the Java 2 SE JRE installations on your system. For example:


Modify this file to reflect your system configuration by adding, removing, or deleting javaws.cfg.jre.<n>.location, javaws.cfg.jre.<n>.path, javaws.cfg.jre.<n>.platform and javaws.cfg.jre.<n>.product entries. Make sure that the javaws.cfg.jre.default=<n> refers to an existing entry. Entries are numbered consecutively starting at 0.

Java Web Start technology will not work with any version of the Java RE 1.1.x software, or earlier versions.


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