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There are several ways to profile an applet.

1. Manually stick timing code into the various method calls and find out where the time is going by analyzing that data (output according to some scheme of your own). This is not recommended unless none of the other ways can be made to work.
2. Run using the appletviewer (should be in your JDK "bin" directory), passing any profiler parameters using the -J parameter, for example appletviewer -J-Xrunhprof:cpu=samples myappletpage.html or appletviewer -J-Xprof myappletpage.html.
3. Run the applet in a normal JVM using the Sun appletviewer class (sun.applet.AppletViewer), and using whatever profiler you want operating as normal for any JVM. For example java -Xrunhprof:cpu=samples sun.applet.AppletViewer myappletpage.html or java -Xprof sun.applet.AppletViewer myappletpage.html.
4. Run the applet in your preferred browser and figure out how to connect your preferred profiler to the Java plug-in or embedded JVM. This last seems to be difficult to do, and only some profilers will work with some browsers. You need to check with your profiler vendor to figure out how to do this, though it may be a FAQ so there could be a simple set of instructions to follow.

Beyond the technicalities, there is nothing special about profiling applets: the code needs to be optimized in the same way any Java program would be optimized. There are a couple of extra concerns to do with applet download and startup time, which means that you want to have the applet and all support resources in a compressed jar file. Although even better is to have the applet start up with almost no resources and minimal class file content, i.e. as fast as possible, then for it to download all further resources it needs while keeping the user occupied or entertained.

The JavaPerformanceTuning.com team

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