After five and a half years full-time work on a product ranking engine project, which revolves around a 64,839 line applet, the browser companies have seen fit to dump applets.
At this point I am in no position to convert the applet to another language (unless I get a huge injection of funds to hire a team of programmers). My partner is not going to support me for another two years.
I know the questions are rather vague and I should be keeping up with the latest tech, however I've had chronic earaches for 14 years that affect memory and concentration, so programming is difficult enough without trying to keep up with the latest developments in software as well. The reason I am asking for advice is that I don't want to make another monumental screw up.
Question 1: My understanding is that Java Web Start launches the application, but it then cannot communicate back to the JSF web page any more (JSF2.0). Is there any way of getting around this?
Question 2: Can anyone suggest any other options other than re-coding the whole thing?
Question 3: Is it likely that applets will be altered to use the latest plugin format or are they gone for good? Does anyone have any inside information on this?
Overview of the applet's requirements:
The applet allows a user to customise some or all of the product ranking criteria, which has been preset by a panel of knowledgeable experts, to their own particular needs. The criteria is stored and edited via graphs (custom painted jPanels).
The ranking criteria can be altered entirely using the mouse (to change the graph shapes), though some values can be entered using the keyboard if the user wishes. Once customised, the applet is then used to submit the changes to the ranking engine server.
It is also used to allow third party experts to alter the ranking criteria to create their own product usage category ranking criteria. The third party expert can then place links on their own web site that will allow users to rank products using the third party expert's own ranking criteria. This allows anyone to create their own ranking criteria for use by others.
The applet uses a plugin bean that is also used in a standalone Java editor application, which is used to create a product usage ranking criteria file from scratch (the editor is 77,710 lines of code, though 61,257 lines of that is the plugin which is also used in the applet). This means most likely having to convert the editor as well, as the two are inextricably linked. The plugin basically is the applet and also the editor.
The plugin can capture, edit and store ranking criteria for virtually anything the human brain can rank. Thanks to the graphs, it can use any attribute that the brain uses, and for which we have no formal system of measurement; hence why the applet is so damn big.
Your question is probably too broad for Stack Overflow, but I'll give a brief response.
Java Web Start is probably the best route for you. This technology is basically a convenient way for a user to obtain, install, and run a Java desktop app. The web browser is only used to initially download a small XML file describing your app and where to get the app. The Java Network Launching Protocol (JNLP) defines these pieces of information stored in that XML file. Your app will be downloaded from a server, and saved to the local machine. A Java Runtime Environment (JRE) can be downloaded and installed if need be as part of the process.
By default the app runs within a security sandbox similar to Java Applets. But you can sign your app and define security protocols to break out of some of those restrictions including making network connections.
The bulk of your programming would remain intact. The app is still pure Java, running in a JVM. You would need to do a bit of reprogramming to be a desktop app rather than packaged as an Applet. And you would have to learn about easing those sandbox restrictions. And your app will have a menu bar of its own as a full-fledged app, so you may want to take advantage of that. But the guts of your app would remain the same.
Over the years, Sun & Oracle have put efforts into improving Java Web Start. Unfortunately it came too late after Java-on-the-desktop had lost too much mind-share. And Swing never got the overhaul it so desperately needed. So Java Web Start never went big-time. But Java Web Start does work as advertised, so give it a try.
While there were some security issues years ago, I believe they have been resolved long ago. The many infamous security problems with Java were largely involving the web browser plugins bridging between browsers and the Java JRE; those problems do not affect Java Web Start (though you should do your own research to confirm).
For the general public, Java Web Start may be too much to ask of new, anonymous, and less-motivated users. For a commercial product with a user-base of eager customers, it may the perfect solution for you. I suggest you do some more study, read the Wikipedia page, study the Oracle technology page, look at the Tutorial, read this overview by John Zukowski that includes an example of network (making socket connection to time.nist.gov), and so on.
The Vaadin framework is an open-source free-of-cost professional user-interface development framework that uses pure Java to run your app on a server in a Java Servlet web container while automatically generating a user-interface using standard web technologies (HTTP, HTML, CSS, JavaScript, GWT, WebSocket, etc.) for presentation within a regular web browser (Firefox, Chrome, Safari, IE, Edge, etc.). As a graybeard, I think of Vaadin as an X Window System for the new millennium: The user interacts with screen widgets on their local computer but the business logic of the app is executing on the server, and the server is updating the remote UI as a result of that business logic executing.
Vaadin is not yet-another-web-templating system. Instead, your app is written in pure Java. No need for you to learn the alphabet-soup of web technologies listed above. Vaadin takes care of that for you, auto-magically. You say in Java “I want a label, then a field, and a button” and Vaadin makes those appear in the web browser.
Using Vaadin would allow you to retain your Java code for the business logic part. But you would need to re-write the user-interface parts to use Vaadin widgets instead of Swing widgets. This would not be so terribly difficult as Vaadin was inspired by the general style of Swing, defining layouts governed by layout managers in which you place your various widgets (fields, labels, buttons, etc.).
Vaadin can make very professional business-oriented apps that feel almost like desktop business apps. Tip: I prefer the Reindeer theme for business apps over the newer Valo theme.
But you mentioned some kind of free-form drawing canvas in your Swing applet. That may be a sticking point. I do not know of such a widget for use within a Vaadin app. I am not saying there is no such thing, I just do not know of any. There are slider widgets that may useful, but I don't clearly understand your needs in that regard.