Browsers & Java

by Michael Thomas

Which Browser should I use?

I prefer MS IE (Internet Explorer). However Netscape will work just fine. Make sure you are using the latest versions. Click here to find links to upgrading to a later version of the browser you use.

Problems

Applets take a very long time to load ( several min instead of seconds ).
Solution:
IE 6.x: ools, Internet Options, Advanced, Section: Java (Sun) - uncheck all items.
Ex: Use Java 2 v1.4.0_01 for <applet> (requires restart)

Enabling Java

Most browsers have a way to enable or disable the ability to allow Java applets to run.

MS IE 5.0 and higher - Default is enabled.
- Tools, Internet Options, Security.
- Now choose the zone (click once): Internet, Local Intranet.
- Now click "Custom Level"
- Look for Microsoft VM, Java Permissions. There is several options. One option is "Disable Java".
MS IE 4.0 and lower: I think the latest versions have JAVA always enabled. However, you may want to see if your version has a box for JAVA enable.
- Choose: Tools, Internet Options, Advanced. Then look for JAVA VM and see if you have a JAVA enable box. (Java Console, JIT, or Java logging is not the options you are looking for!)
Netscape:
- Choose: Edit, Preferences, Advanced, then click on the box "Enable Java".
- Next, exit the HTML file (Click on Back) then click on a URL link or type in the URL. (Warning: Clicking on Reload may not work! Also, clicking on BACK then FORWARD may not work! Netscape v6.0)

Viewing the Java Console

You may want to view the Java Console if an Applet has problems loading or running.

Sun's JVM
- Starting JRE 1.6.0_10 (sometime around Nov of 2008)
  - Enable the Java Console option to show up.
    - Start, Settings, Control Panel, Java
      Click Advanced Tab
      Java Console
      Select, "Show Console"
      (Note: Now when an applet loads the Java Console will open up!)
    - Also, look at the "Debugging" options.
- Before JRE 1.6.0_10
  Tools, Sun Java Console
MS IE if Using Microsoft's JVM (very old browsers) - Choose: View, Java Console.
- Must have Java Console enabled. Tools, Internet Options, Advanced (tab), Microsoft VM. Check: Java Console enabled (requires restart).
Netscape - Choose: Communicator, Tools, Java Console.

Java Options and Browsers

General Notes
- Warning for IE, I've seen web applications that, once worked, fail and get Java exceptions when you choose to use the Java PlugIn. The web applications normally connect to sockets. I haven't had time to figure out why.
- With the Java PlugIn installed and enabled, you have access to the installed Sun JRE vs the Browsers JRE. So now you have access to the latest Java classes.
IE 6.x (Tools, Internet Options)
- Advanced, Section: Java (Sun)
  - Now select the PlugIn you want to use:
    Ex: Use Java 2 v1.4.0_01 for <applet> (requires restart)
  - Now, reboot your machine.
- Advanced, Section: Microsoft VM Options:
  - Java console enabled.
  - Java logging enabled.
  - JIT compiler for virtual Machine enabled.
- Security, Then select the Zone (Internet, Local Intranet, etc...)
  - Microsoft VM, Java Permissions: Custom, Disable Java, High Safety, Low safety, or Medium safety.
  - Scripting, Scripting of Java Applets: enable, disable, or prompt.
IE 5.x (Tools, Internet Options)
- Section: Java (Sun) - may or may not have this option.
  - Java 2 v1.4.0 for <applet>. This allows the Java Plug-In to become the default Java runtime.
- Microsoft VM Options:
  - Java console enabled.
  - Java logging enabled.
  - JIT compiler for virtual Machine enabled.
Netscape 4.75 (Edit, Preferences)
- Advanced
  - Enable Java

Browser Versions and the JVM Implementation

Warning: This is my notes from my experience and may not be correct.

Browsers implement a certain JVM version. IE 5.5 has an option (ex: "Internet Options, Advanced: "Java 2 v1.4.0 for <applet>" under "Java (Sun)") to use an external JVM like Sun's JRE which will allow Applets to run with the latest version of Java JRE. See my notes below.

Until IE 5.x and NS 6.x the browsers implemented the Java JDK/JRE. Java applications used the installed Sun Java JRE - not the browsers. If you wanted to use the Sun Java JRE you had to install the Java Plug-In which had to be accessed via special html tags. With Java JRE v1.4.0 with Browsers IE5.5 & NS6.0 you can choose to update your browser to use Sun's Plug-In (JRE) for the default Java JVM . In this case, you don't need the special html tags to use the Plug-In. This now allows you to have access to the latest Java JRE instead of waiting for a browser implementation.
Example of IE's Option: IE's "Internet Options, Advanced: "Java 2 v1.4.0 for <applet>" under "Java (Sun)".
IE - Internet Explorer by Microsoft
- IE 4.x - JDK 1.1
- IE 5.x - JDK 1.1 - unless you check the option in IE's "Internet Options, Advanced: "Java 2 v1.4.0 for <applet>" under "Java (Sun)".
- IE 5.x using Java Plug-in for default Java runtime - This will use the JRE installed by Sun, not the browser. Therefore the version can be current.
  See: IE's "Internet Options, Advanced: "Java 2 v1.4.0 for <applet>" under "Java (Sun)".
NS - Netscape Communication by Netscape
- NS4.x - JDK 1.1
- NS6.x - JDK 1.2
- NS6.x using Java Plug-in for default Java runtime - This will use the JRE installed by Sun, not the browser. Therefore the version can be current.
HotJava - by Sun
- 3.0 - JDK 1.1.7B