JavaTM Web Start is an application deployment solution based on Java technology. It is a convenient channel to connect computers and the Internet, allowing users to run and manage applications completely outside the network. Java Web Start provides a simple way to activate an application with a single click, and ensures that the latest version of the application is always running, thus avoiding a complicated installation or upgrade process.

Traditionally, publishing software through the Web requires users to find and download it on the Web, and then store and execute the installation program in the system. After executing the installation program, you will be prompted to specify the installation path and installation options, such as full installation, typical installation or minimum installation. This is a time-consuming and complicated task, which must be repeated when installing each new version of the software.

On the contrary, applications deployed through the Web, such as your favorite HTML-based email client software and calendars, auction websites, etc., are very easy to install and use. The web browser automates the whole process. There is no complicated download, installation and configuration process, and make sure that you always use the latest version.

Java Web Start technology can provide full-featured applications with the same benefits as the above-mentioned Web browser for HTML applications. Java Web Start technology is a Web-oriented application deployment solution. Using full-featured applications instead of HTML-based client software has several advantages:

The highly interactive user interface is comparable to traditional applications such as word processing and spreadsheet software.

Lower bandwidth requirements. The application doesn't need to connect to the Web server every click, it can cache the downloaded information. In this way, it can achieve better interactivity on low-speed connections. Support offline use.

Of course, you still have to download the application when you use it for the first time. Therefore, HTML-based applications have the overhead of first activation. Usually, it takes several seconds to open a web page. It takes several minutes to download applications based on Java TM technology through a typical modem connection. Java Web Start caches all downloaded files on the local computer. In this way, although the initial activation cost of an application is higher than that of an HTML page, the application can be started immediately afterwards, because all the required resources can be obtained locally.

Every time you start, Java Web Start will check whether the web server has an updated version of the application, and if so, it will automatically download and start. In this way, the application will be updated automatically. There is no complicated upgrade process.

safe

Java Web Start is built on the Java 2 platform and provides a perfect security architecture. By default, applications launched through Java Web Start will run in a controlled environment ("sandbox"), with limited access to files and networks. Therefore, starting an application through Java Web Start can maintain the security and integrity of the system.

Applications can request unrestricted access to the system. In this case, when the application starts for the first time, Java Web Start will display a security warning dialog box. The security warning will display the information of the vendor who developed the application. If you choose a trusted vendor, the application will start. The source information of the application depends on the digital code signing.

installation instructions

For installation instructions and system requirements of this version, please refer to the installation guide.

Using Java Web Start software

Java Web Start enables you to start applications based on Java technology directly through the Web. Applications can be launched in the following three ways:

Start from a Web browser by clicking the link.

Starting with Java Web Start's built-in "Application Manager", the manager will keep track of recently used applications and provide quick access to favorite applications.

Start with the desktop icon or the Start menu (Microsoft Windows only).

Either way, every time you start the application to check whether there is an updated version of the application, Java Web Start will reconnect to the web server.

Start with a Web browser.

On the demo page of javawebstart (/products/javawebstart/demos.html), there are many links to applications, which can be started by clicking the mouse. Try clicking the Start button to start a different application. The Web browser will start Java Web Start, which will download, cache and execute the specified application. You will notice that the second time you start the application, the speed is obviously faster, because it already exists locally and you don't need to download it.

Most demo programs on the page can be downloaded and executed directly without user intervention. These applications run in a restricted environment, can't access local disks and networks, and can guarantee that no virus will be installed on the computer.

Some demos require additional permissions, such as accessing the local hard disk. For these applications, a security dialog box will pop up to display the source information about the application according to the digital signature of the code. The application will only run if you decide to trust the supplier.

That's all you need to use Java Web Start, but how does it work? The HTML link that starts the application is actually a standard HTML link. However, instead of pointing to other web pages, it links to a special configuration file called JNLP file. The Web browser checks the extension and/or MIME type of the file to determine that it belongs to Java Web Start. Then start Java Web Start using the downloaded JNLP file as a parameter. Java Web Start downloads, caches and runs applications according to the instructions of JNLP files.

Start with the built-in application manager.

The application manager is a built-in part of the Java Web Start product. It enables you to start applications that have been started through Java Web Start quickly and easily. Manager consists of "History" menu and "Start/Program" menu, which provides corresponding functions for applications based on Java technology deployed through the Web. You can also link to the home page of the application through the Application Manager to view its additional information.

You can double-click the application icon or click the Start button to start the application from the Application Manager.

Another important function of the Application Manager is the Preferences dialog box, which enables you to view and modify the settings used by Java Web Start. For example, it includes tabs that allow you to:

Specify the HTTP proxy (or tell Java Web Start to use the default browser settings).

Clear the downloaded application cache.

Specify the location of different versions of the Java runtime environment.

Specifies whether to display the Java console.

View the root security certificate collection.

You can start the application manager by clicking the Java Web Start icon on the desktop or the icon in the Microsoft Windows start menu. On SolarisTM operating environment and Linux, start it by calling javaws command in Java Web Start installation directory. You can also start the application manager from a Web browser; See the demo page (/products/javawebstart/demos.html) for an example.

Start with the desktop icon or the Start menu (Microsoft Windows only).

Java Web Start technology can automatically create shortcuts for Java technology-based applications deployed through the Web in Microsoft Windows desktop and start menu. By default, if you need to create a shortcut, Java Web Start will prompt you the second time you start the application. This parameter can be changed through the preferences panel.

You can also add and delete shortcuts using the menu items Application/Create Shortcuts and Application/Delete Shortcuts through the Application Manager.

Use Java Web Start software behind proxy server/firewall.

Java Web Start software must be configured with the correct proxy settings to start the application from outside the firewall. Java Web Start software will automatically try to detect proxy settings of default browsers (Internet Explorer or NetscapeTM browser on Microsoft Windows, Solaris operating environment and Netscape browser on Linux). Java Web Start technology supports most Web agent automatic configuration scripts. It can detect proxy settings in almost all environments.

If proxy settings cannot be automatically detected, you will be prompted to specify proxy settings the first time you use Java Web Start. Java Web Start will also prompt for the user name and password required to access the authentication proxy server. The user name and password will be saved as the current entry information of Java Web Start. However, when calling a new Java virtual machine, if you visit a secure website, you will be prompted to enter your user name and password, because this information is stored with the Java virtual machine instance.

You can also use the Java Web Start preferences panel to view or edit the proxy configuration. Start the application manager by clicking the icon on the (Microsoft Windows) desktop or typing. /javaws command under the installation directory of Java Web Start (Solaris operating environment and Linux), and then select Edit/Preferences. If you are in an environment of accessing the Web through a proxy server, it is recommended to use the Java Web Start preference panel to check whether the settings are correct.

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