Java Tip 51: Browser upgrades

Find out how to upgrade your browser to support JDK 1.1

Perhaps you've seen one of the following messages displaying in the status bar of your browser when it tries to run a Java applet:

  • java.lang.NoClassDefFoundError
  • java.lang.NoSuchMethodError

If you guessed that these errors occurred because your browser wasn't compatible with JDK 1.1, you were right. So now what?

Choosing your browser

If you use Windows 95/NT and don't have a strong political aversion to Microsoft, your best bet is Internet Explorer 4.0. IE 4.0 is fast, 99.99 percent compatible with JDK 1.1, and integrates well in Windows. Big surprise, here.

For all other situations, you should probably go with Netscape Navigator 4.04. If you're currently running Navigator and would like to quickly upgrade to the most current version, you can use Netscape's "SmartUpdate" feature (see Resources). Simply go to Netscape's Automatic Software Upgrade Web page and follow the instructions on the screen. It's really quite simple.

Manually installing JDK 1.1 support for Windows 95/NT

If you already have Netscape Communicator 4.04 installed and want to add in 1.1 support manually (for those of you who don't trust automation!), download, unzip the file, and copy the contents to Communicator's folder, overriding the existing files. For example, if your browser is installed in C:\Netscape, the following files will be updated:


This patch provides support for AWT 1.1 and JavaBeans for Windows 95/NT only. See Resources to download the 1.1 support pactch for other ports.

A note to Java developers

If you are developing applets in Java, you should always test them with Sun's HotJava 1.1.2. This all-Java browser may not be the fastest implementation of the applet container, but it is certainly the best. After you get your applets working properly with HotJava, continue testing with Netscape Navigator and Internet Explorer. You'll make all of us professional surfers a whole lot happier!

Andrei Cioroianu has a B.S. in Mathematics - Computer Science (1997). He is currently studying for his M.S in Artificial Intelligence at the University of Craiova in Romania.

Learn more about this topic

  • Download HotJava 1.1.2
  • Download Internet Explorer 4.01
  • Use Netscape's Smart upgrade feature to Netscape Communicator 4.04
  • Download the latest version of Netscape Communicator
  • Download the Netscape Communicator/Navigator 4.03/4.04 support for JDK 1.1