Applet Scripting: Applets & Javascript

Examples

• My Applet Scripting Examples

  • Download the source for the examples below.

  • Applets and Javascript - Example of using JavaScript to talk to an Applet (Applet scripting).

  • Applet Scripting from a JAR file - Jar (Java Archive)

Applet Scripting Issues

• MS  JVM (Microsoft's) vs Sun's JVM & applets.  The statements below have been tested with IE v6.0.
  • Java Applets compiled with SDK 1.5 will not work with MS JVM.  You will need to use Sun's JVM.  MS JVM can't load the .class file.
  • MS JVM (Microsoft's Java Virtual Machine) is based on API 1.1.6
  • Java Applets compiled with JDK 1.2 will work with MS JVM provided that you just use API 1.1 calls.

• IE - Java Console

  • MS JVM

    • View the Java Console (for Microsoft JVM only).

      • Launch IE.

      • Click View, Java Console.  (Note: If you don't see the option "Java Console" then you need enable "Java Console".

    • To enable "Java Console"

      • Launch IE

      • Tools, Internet Options, Advanced

      • Find the "Microsoft VM" section

      • Check - "Java console enabled (requires restart)
        Check - "Java logging enabled"

      • Now close all of the browser windows (this is a restart).

      • Now launch IE and view the Java Console.

  • Sun's JVM

    • View the Java Console (for Sun's JVM only).

      • Launch IE.

      • Tools, "Sun Java Console".  (If this option doesn't appear then you need to install Sun's JVM.)

    • Enable Sun's JVM

      • Launch IE.

      • Tools, Internet Options, Advanced

      • Find the "Java (Sun)" section.  (If you don't have one then you don't have Sun's JVM installed.)

      • Check the "JVM that you want enabled."

      • Now close all of the browser windows (this is a restart).

      • Now launch IE and view the Java Console.

       

• IE settings - allow Applet Scripting

  • Example Error if Applet scripting is not allowed:
    A Runtime Error has occurred.
    Do you wish to Debug?
    Line: <line no. where you access the applet>
    Error: Object doesn't support this property or method.

  • Steps to: Allow Applet Scripting (Javascript can talk to an Applet)
    Applet scripting - allowing Javascript to communicate with an Applet.
    • Steps using default security levels.
      • Launch IE.
      • Tools, Internet Options,
      • Click on the tab: Security
      • Click on the "Internet" world icon.  The zone will show "Internet".
      • Click on "Custom Level".  The "Security Setting" window will open up.
      • At the bottom, select "Medium" for the "Reset to:" option.  Click "Reset".
      • Click "OK".
      • You should now be back at the "Internet Options" window.  The security level for this zone should be "Custom".
      • Click "Default Level" - Note:  This is suppose to set the security to "Medium" (the same steps you just took above).
      • Click Apply.
      • You are finished!
    • Security Properties
      • Follow the steps above to get to the "Security Setting" window.
      • Look for the section "Scripting".  Click "Enable" for "Scripting of Java Applets".
  • Steps to: Display JavaScript Errors
    • Launch IE.
    • Tools, Internet Options,
    • Click on the tab: Advanced
    • Under the section "Browsing"
      • UnCheck - Disable Script Debugging (Internet Explorer)
      • UnCheck - Disable Script Debugging (Other)
      • Check - Display a notification about every script error