Requirements

Requirements needed to run a virtual experiment depends on which execution method is chosen.
Each experiment can be executed:

Some details on the Java Web Start Technology are found in the Java Web Start Information section.


RUNNING EXPERIMENTS AS STANDARD JAVA APPLETS :

Make sure your system meet the following two requirements :

  1. A Java Virtual Machine (JRE 1.4.x or a more recent one) is installed.
    It's possible to test if one is already installed, by clicking here.
    Yuo can find one at Sun Site
    (look for download link).


  2. JOGL library is installed.
    Click here to connect to the official home page of the JOGL project. In section 'Resources -> Builds', click on 'JOGL archived builds' and download the version suitable for your platform.


RUNNING EXPERIMENTS AS JAVA WEB START APPLETS:

To run a virtual experiment with the Java Web Start Technology, it is needed that your system meets the two requirements listed above, required for the STANDARD applet execution, plus a new requirement:

  1. "Java Web Start" environment is installed (NOTE: this environment is normally included in the latest JRE releases, so this requirement can be automatically satisfied by fulfilling the first requirement of the previous section).

To test if your current system is ready to use this technology, click here.
If you need to install it, click on the following image to find the necessary files.


JAVA WEB START INFORMATION

Java Web Start (JWS) software is the Sun reference implementation for the "Java Network Launching Protocol" (JNLP) (for the Telelab project the reference version is 1.0.1 for this protocol).
This protocol has been developed to allow the easy remote execution of java applications and applets over the Internet.
It offers an extremely simple way of launching applets, directly from a web page, but without the need of a web browser. This means that every dependance from specific browser implementations does not affect at all the applet execution.
An important point about security, is that however the applet is allowed to run outside of the browser environment, any security restrictions normally applied by the Java Virtual Machine for applets is already active, thus still protecing the user from malicious software.
For example, the security sandbox prohibits the applet from direct access to the client file system, while allowing the user to explicitly grant a single disk access, for file reading or writing, at run-time, by displaying a dialog box on the screen, as shown in the next figure.


Moreover, after an applet has been launched for the first time, following calls can be performed off-line, entirely on the client machine, alleviating the user from establishing an Internet connection to the server each time he wants to re-start.
Finally, every time the applet is started again, JWS automatically (and invisibly from user) tries to find an updated version, if avaliable, and then replace the whole version stored on the client machine, or even some part of it ( Incremental and Transparent Update ) . If an updated version is not available, or an Internet connection is not active, the previous version will be used, retrieving it from the disk cache ( Offline Support ) .

Summarizing, the Java Network Launching Protocol and API is a Web-centric provisioning protocol and application environment for Web-deployed Java 2 Technology-based applications. An application implementing this specification is called a JNLP Client.
The main concepts in this specification are:

  • A Web-centric application model with no installation phase, which provides transparent and incremental updates, as well as incremental downloading of an application. This is similar to the model for HTML pages and Applets, but with greater control and flexibility.
  • A provisioning protocol that describes how to package an application on a Web server, so it can be delivered across the Web to a set of JNLP Clients. The key component in this provisioning protocol is the JNLP file, which describes how to download and launch an application.
  • A standard execution environment for the application. The execution environment includes both a safe environment where access to the local disk and the network is restricted for untrusted applications, and an unrestricted environment for trusted applications. The restricted environment is similar to the well-known Applet sandbox, but extended with additional APIs.

The launching scheme is based on an XML file (with extension .jnlp) activating the JNLP client on the client machine.
This JNLP client is responsible for transferring all necessary files to the client machine and then to launch the application.

You can download the specifiaction of the JNLP protocol and API here.