Which option is suitable to replace Java Applet?

Question

I would like to replace Java Applet which currently needs to use client's resources, i.e. external readers, and to communicate with a server via socket.

Reason: 1. I have thousands of client machines using this Java Applet program, and most of them are running out-dated JRE. When the Java Applet program is updated / added new features, all client machines will need updating the latest JRE.

Expected Solution:

The Java Applet program would be expected to be replaced by a web-based application, which allows to compile and run source code at client's side such that the new web-based application could still use client's resources and communicate with server via socket.

Can I use JavaScript to achieve it?

I would very appreciate your help/suggestion for this problem. Thank you!

Answer 1

JavaScript is a scripting language that gets evaluated in the browser. I would not describe it as compiling and running but yes, it does mean you can run code in the client and is commonly used to create applications that run in the browser.

There's a staggering amount of frameworks that you can use to write your application. Take a look at the TodoMVC site to see the same TODO app created using several different frameworks.

If you come from Java applets, GWT may be interesting to look at.

If you wish to let the JavaScript client listen for messages from the server, take a look at websockets.

The smart card reader is going to be a problem, though! See Architectures to access Smart Card from a generic browser? Or: How to bridge the gap from browser to PC/SC stack?

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By the way:

The real issue with outdated JREs is not that your code will not run on old JREs, you can create perfectly fine applets using java 1.4 or java 5. Any libraries you may need you can deploy alongside your applet. The pain is a security problem. Anything but the latest version Java plugin is getting actively exploited and puts the user at risk. Occasionally, even the latest version is not safe.