B JInitiator

This section describes the benefits of using Oracle JInitiator as a Web browser plug-in. Oracle JInitiator enables users to run Oracle Forms applications using Netscape Navigator or Internet Explorer. It provides the ability to specify the use of a specific Java Virtual Machine (JVM) on the client, rather than using the browser's default JVM.

Oracle JInitiator runs as a plug-in for Netscape Navigator and as an ActiveX component for Internet Explorer. Oracle JInitiator does not replace or modify the default JVM provided by the browser. Rather, it provides an alternative JVM in the form of a plug-in.

Oracle provides two Jar files (frmall.jar and frmall_jinit.jar). frmall.jar is a standard Jar file, and frmall_jinit.jar is a Jar file with extra compression that can only be used with Oracle JInitiator.

B.1 Why Use Oracle JInitiator?

Oracle JInitiator delivers a certified, supportable, Java Runtime Environment (JRE) to client desktops, which can be launched transparently through a Web browser.

Oracle JInitiator is Oracle's version of JavaSoft's Java Plug-in. The JavaSoft Plug-in is a delivery mechanism for a JavaSoft JRE, which can be launched from within a browser. Likewise, Oracle JInitiator is providing a delivery mechanism for an Oracle certified JRE, which enables Oracle Forms applications to be run from within a browser in a stable and supported manner.

In addition to providing a certified platform for the execution of Oracle Forms applications, Oracle JInitiator provides a number of additional features over and above the standard JavaSoft Java Plug-in. These include Jar file caching, incremental Jar file loading, and applet caching (see Chapter 8, Minimizing the Application Startup Time).

B.2 Benefits of Oracle JInitiator

Oracle JInitiator provides these benefits:

It allows the latest Oracle-certified JVM to run in older browser releases.
It ensures a consistent JVM between different browsers.
It is a reliable deployment platform. JInitiator has been thoroughly tested and certified for use with Forms Services.
It is a high-performance deployment environment. Application class files are automatically cached by JInitiator, which provides fast application start-up.
It is a self-installing, self-maintaining deployment environment. JInitiator automatically installs and updates itself like a plug-in or an Active-X component. Locally cached application class files are automatically updated from the application server.

B.3 Using Oracle JInitiator

The first time the client browser encounters an HTML file that specifies the use of Oracle JInitiator, it is automatically downloaded to a client computer from the application server. It enables users to run Oracle Application Server Forms Services and Graphics applications directly within Netscape Navigator or Internet Explorer on the Windows 98, NT, 2000, and XP platforms.

The installation and updating of Oracle JInitiator is performed using the standard plug-in mechanism provided by the browser. Oracle JInitiator installation performs the required steps to run Oracle Forms applications as trusted applets in the Oracle JInitiator environment.

B.4 Supported Configurations

Oracle JInitiator supports the following configurations:

B.4.1 Windows 98, NT, 2000, XP:

Navigator 4.7.x
Navigator 7.x
Internet Explorer 5.x
Internet Explorer 6.0

B.5 System Requirements

The minimum system requirements for Oracle JInitiator are:

Windows 98, NT, 2000, XP
Pentium 90 MHz or better processor
25MB free hard disk space (recommended 30MB)
16MB system RAM (recommended 32MB)

Note:
These minimum system requirements are for JInitiator only; they are insufficient to run Oracle Forms.

B.6 Using Oracle JInitiator with Netscape Navigator

Oracle JInitiator leverages the Netscape Navigator plug-in architecture in order to run inside the browser in the same way other plug-ins, such as QuickTime movies or Shockwave animations operate. Using the Netscape HTML <EMBED> tag, Web application developers can specify that plug-ins run as part of a Web page. This is what makes it possible for Oracle JInitiator to run inside the Web browser with minimal user intervention.

When Navigator first encounters an HTML page that specifies the use of Oracle JInitiator, users will see a "Plug-in Not Loaded" dialog on the HTML page, which directs the user to the Oracle JInitiator download page. Users can then download the version of Oracle JInitiator for their operating system and install it.

Once Oracle JInitiator is installed, users must shut down Navigator, restart it, and then revisit the original HTML page. Oracle JInitiator will then run and use the parameters in the <EMBED> tag to render the applet. The next time Navigator encounters a Web page that specifies Oracle JInitiator, Navigator will seamlessly load and run the plug-in from the local disk, without user intervention.

B.7 Using Oracle JInitiator with Microsoft Internet Explorer

Oracle JInitiator leverages the Microsoft Internet Explorer extension mechanism for downloading and caching ActiveX controls and COM components. Using the HTML <OBJECT> tag, Web application developers can specify that ActiveX controls or COM components should run as part of a Web page. Such components include Oracle JInitiator.

When Internet Explorer first encounters an HTML file that has been modified to specify the use of Oracle JInitiator, Internet Explorer will ask the user if it is okay to download an ActiveX control signed with a VeriSign digital signature by Oracle. If the user clicks "Yes," Internet Explorer will begin downloading Oracle JInitiator. Oracle JInitiator will then run and use its parameters in the <OBJECT> tag to render the applet. The next time Internet Explorer encounters a Web page modified to support Oracle JInitiator, it will seamlessly load and run Oracle JInitiator from the local disk, without user intervention.

B.8 Setting up the Oracle JInitator Plug-in

You can setup the Oracle JInitiator Plug-in after you install it on your server for server-based testing purposes only. Then continue by:

Adding Oracle JInitiator Markup to Your Base HTML File
Customizing the Oracle JInitiator Download File
Making Oracle JInitiator Available for Download

B.8.1 Adding Oracle JInitiator Markup to Your Base HTML File

To add Oracle JInitiator markup to your base HTML file:

Open your base HTML file within a text editor.
Add the OBJECT and EMBED tags.

For examples of added markup, refer to Appendix C.3, "base.htm, basejini.htm, and basejpi.htm Files".

B.8.2 Customizing the Oracle JInitiator Download File

The Oracle JInitiator download file (JINIT_DOWNLOAD.HTM) is the template HTML file that allows your users to download the Oracle JInitiator file.

To customize the Oracle JInitiator download file:

Open the JINIT_DOWNLOAD.HTM file within an HTML or text editor.
Modify the text as desired.
Save your changes.

B.8.3 Making Oracle JInitiator Available for Download

To make Oracle JInitiator available for download:

Copy jinit13x.EXE to your Web server.

You must copy jinit13x.EXE to the location that was specified within the base HTML file.
Copy JINIT_DOWNLOAD.HTM to your Web server.

You must copy JINIT_DOWNLOAD.HTM to the location that was specified within the base HTML file.

B.9 Modifying the Oracle JInitiator Plug-in

Continue modifying the Oracle JInitiator Plug-in by:

Modifying the Cache Size for Oracle JInitiator
Modifying the Heap Size for Oracle JInitiator
Checking and Modifying the Proxy Server Setting for Oracle JInitiator
Viewing Oracle JInitiator Output

B.9.1 Modifying the Cache Size for Oracle JInitiator

The default cache size for Oracle JInitiator is 20000000. This is set for you when you install Oracle JInitiator.

To modify the cache size for Oracle JInitiator:

From the Windows Start menu, choose Start|Settings|Control Panel|Oracle JInitiator.
Click the Basic tab.
In the Java Run Time Parameters field, specify the Dcache size. For example, specifying Dcache.size=20000000 sets the cache size to 20MB.

B.9.2 Modifying the Heap Size for Oracle JInitiator

The default maximum heap size for Oracle JInitiator is 64MB. This has been set for you when you install Oracle JInitiator.

To modify the heap size for Oracle JInitiator:

From the Windows Start menu, choose Start|Settings|Control Panel|Oracle JInitiator.
Click the Basic tab.
In the Java Run Time Parameters field, specify the mx size. For example, specifying mx64m means setting maximum heap size to 64MB.

B.9.3 Checking and Modifying the Proxy Server Setting for Oracle JInitiator

To check and modify the proxy server setting for Oracle JInitiator:

From the Windows Start menu, choose Start|Settings|Control Panel|Oracle JInitiator.
Click the Proxies tab.
Select the Use Browser Settings checkbox to allow Oracle JInitiator to use the settings in your browser's configuration dialog box. If you want to use another proxy server setting, be sure the box is not selected. Then, enter the host name for the proxy server in the Proxy Address field.

B.9.4 Viewing Oracle JInitiator Output

To view Oracle JInitiator output:

From the Windows Start menu, choose Start|Settings|Control Panel|Oracle JInitiator.
Click the Basic tab.
Select Show Java Console to enable debug output.

B.10 Modifying the baseHTML file

When you run an Oracle Forms application with the help of JInitiator, JIinitiator reads parameter values from the formsweb.cfg file and passes these values into the baseHTML file. If you want to create a static baseHTML file so that the same values are read all the time, you need to manually place them in the baseHTML file.

For an example of the Oracle JInitiator markup for both Microsoft Internet Explorer and Netscape Navigator, see Appendix C.3, "base.htm, basejini.htm, and basejpi.htm Files". Adding these tags to your baseHTML file will enable your applications to run within both Netscape and Microsoft browsers.