What is Java Web Start and how is it launched?

What is Java Web Start?

The Java Web Start software allows you to download and run Java applications from the web. The Java Web Start software:

• Provides an easy, one-click activation of applications
• Guarantees that you are always running the latest version of the application
• Eliminates complicated installation or upgrade procedures

Getting Java Web Start Software

Java Web Start is included in the Java Runtime Environment (JRE) since release of Java 5.0. This means that when you install Java, you get Java Web Start installed automatically. The Java Web Start software is launched automatically, when a Java application using Java Web Start technology is downloaded for the first time. The Java Web Start software caches (stores) the entire application locally on your computer. Thus, any subsequent launches are almost instantaneous as all the required resources are already available locally. Every time you start the application, the Java Web Start software component checks the application's website to see if a new version is available, and if so, automatically downloads and launches it.

Launching an Application Using Java Web Start Software

• From a browser: Click on a link from a web page.
• From desktop icon: If you use an application frequently, you can create a shortcut on your desktop or in the Start Menu. Java Web Start may ask if you would like to create shortcuts or an entry in the Start Menu. If you say 'yes,' all future launches of the application can start without a browser.
• From Java Application Cache Viewer: Java Web Start also provides an Application Cache Viewer which you can launch from the Java Control Panel. The Cache viewer enables you to directly launch applications that you have downloaded.
  
  Instructions to launch from Application Cache Viewer
  1. Go to Start > Settings > Control Panel > Double click on the Java icon. The Java Control Panel will start.
  2. Click on the General tab
  3. Click on the Settings button from the Temporary Internet Files section
  4. Click on the View Applications button
  5. Double click on the respective application from the list that you want to launch

• From command prompt: You can also launch an application from a command prompt by typing javaws jnlp_url where jnlp_url is a url to the jnlp file of the application.
  
  
  1. Go to Start > Run > type "command". A command prompt window will appear.
  2. Type "javaws url_of_jnlp"