Develop Reference

What does one do regarding applets now that Chrome doesn't support Java?

Without thinking, I created an entire program in Java and began designing a website to use this applet. All it does is create image in a certain way but there is a bit more code (classifications and default values/images) that I just felt was easiest to do with Java. Now I have a Java app and HTML CSS and JavaScript that I can't seem to do much with.
I have thought of 2 ideas (below) but I don't know what the general alternative is to applets nowadays.
I have a spare PC I may use and just alter my applet to run the back-end of a server-based site instead, but I am hesitant to use my own IP and bandwidth for something like this. Also, this app doesn't even need access to the internet so this just seems like way overkill.
I could just release the .jar, but I plan on expanding the available options. I also told people that this website was coming. I'd like to be able to just update the website.
I don't really plan on writing my program in another language. This took me time to make. If there is no way to work Java into my site, I may just abandon the project altogether.
I am mainly concerned with Chrome for this problem.
Edit: I would like to use GitHub as my host, just in case this helps at all.

You can run anything you want on the server, including java programs. So
you could run the image creation program in the server and present the
resulting image using a standard img tag.

I have made a JFrame which I want to put in an HTML script. (I was going to use a JApplet but it has been deprecated)

I'm using IntelliJ IDEA, I have coded a frame which I want to put into an HTML file so I can run it in my browser, how do I do this now that I cannot use JApplet? I have found this documentation: http://docs.oracle.com/javase/tutorial/deployment/webstart/deploying.html and this http://docs.oracle.com/javase/tutorial/deployment/webstart/deploying.html but I am new to programming and find this difficult to follow. I don't know for instance how I would go about putting my class files and the image that I used in a separate directory nor do I know how I go about signing my application so that it will run in a browser.

I want to put into an HTML file so I can run it in my browser,
You can use the Desktop class. This class allows you to access default applications from your desktop.
Read the section from the Swing tutorial o How to Integrate With the Desktop class for more information and working examples.

See Java Plugin support deprecated and Moving to a Plugin-Free Web.
Note that is one of my 'copy/paste comments' that does not explicitly mention JFrame based apps., however the links are still relevant in that Oracle & browser makers would not be phasing out support for applets if they wanted programmers to keep trying to shove rich client apps (e.g. Swing GUIs) into thin client web pages.
OTOH you can offer a JFrame (or a JApplet) to be launched from a link in a web page to end up free floating on the desktop of the user by using Java Web Start.
Even then, it is not a simple matter for the programmer or the end user. The programmer needs to ensure the app is digitally signed using a code signing certificate issued by a CA (usually they are expensive). The end user used to just be able to click the link, 'OK' the prompts produced by the Java virtual machine, and see the app appear on-screen. But now most browsers will download the launch file to the local file system rather than directly hand it to the JVM to be launched. So the user faces an extra step in explicitly finding the downloaded launch file and double clicking it.
This is all due to security concerns related to bugs in the plug-ins that run things in web pages. So if you were to find a way around all these hoops, please let us know. It is a security bug that requires urgent fixing.

What is the best way to turn this Java Swing application into a sandboxed embed-able (applet or Web Start)?

I am working on a primitive online game client that I wrote as a Java Swing application. My problem is that potential users refuse to download and run any unfamiliar executable. I want my game to be reach as many people as possible and users fear that the executable might contain a virus. That is why I would like to embed the game client into my web page instead. How would you turn this Java executable code (liked below) into an applet?
Thus far I have a main which makes the initial connection to the game server...
https://dl.dropboxusercontent.com/u/214507961/Main.java
A Java Swing GUI that I made with the Netbeans GUI builder...
https://dl.dropboxusercontent.com/u/214507961/GUI.form
Object input/output streams connected to my game/web server...
https://dl.dropboxusercontent.com/u/214507961/Clients_Input.java
https://dl.dropboxusercontent.com/u/214507961/Clients_Output.java
And some buffered images for graphics...
https://dl.dropboxusercontent.com/u/214507961/Image_Repo.java
Note that in future development, I would like to replace much of the primitive looking 2D Swing GUI with content rendered with the Lightweight Java Game Library or some other higher-level video game graphics specific library to make the game look better.
Given that information, what is the best way to make this Java application into an embed-able (applet)? Describe your method and reasoning in such a way that even a college freshman could follow.
Note: Following the advice below, I have tried using WebStart, but I still get an intimidating warning:
Update:
I am in the process of refactoring my code so that the top level container is a JPanel.
I have tried making "GUI" extend JPanel and changing the "gamewindow" from a JFrame into a JPanel.
Modified Main:
https://dl.dropboxusercontent.com/u/214507961/Panel_Top_Level_Container/Main.java
Modified GUI:
https://dl.dropboxusercontent.com/u/214507961/Panel_Top_Level_Container/GUI.java
Despite the changes, Netbeans will not allow this program to run with Java Web Start.
When I enable WebStart and Build/Clean, Netbeans creates two files:
I then clicked Build/Clean and it generated two files:
master-application.jnlp
https://dl.dropboxusercontent.com/u/214507961/Panel_Top_Level_Container/master-application.jnlp
preview-application.html
https://dl.dropboxusercontent.com/u/214507961/Panel_Top_Level_Container/preview-application.html
but no JAR file.
Still working on it. AI moved the remainder of this question to:
Why can't I get Netbeans with Java Web Start enabled to work on my executable?
At this point I'm so tired of putting up with the security hassles and see little to no way to get around certification warnings without paying. I have decided that it would probably be better to just re-write the entire client in HTML5 and javascript.

The basic concept is to build your app (GUI basicly) without using applet specific technologies (like commmunication with web page via JS etc.) and with JPanel as a top level container insteed of of JFrame (Window would be accceptable too, as JApplet extends Window). If you do so, that you will be able to deploy the same code as standalone application and via JNLP as applet.

The digital signature could not be verified by a trusted source.
This is caused by the app. being 'self signed' by a digital certificate we generate ourselves using the SDK tools. Security was increased recently so that 'self signed' apps. get that scary warning. This has been discussed extensively across SO in recent times.
Try looking at the posts under applet+security for details.

Redo the client using HTML5 and Javascript so that you don't run into any prompts or security warnings.

How do I create an interface with buttons and text?

I've tried different ways of creating different interfaces and applets. One of the main things I'm trying to do is to get these gui's to display text and show multiple buttons with different text leading to different outcomes. What I'm asking is, what code is necessary to create an applet or an interface (because I fail at telling the difference between the two) and how should I approach building and structuring that.

I recommend you use netbeans because it has an editor and is the easy way to create Applet.
https://netbeans.org/kb/docs/web/applets.html

You have three main choices I can think of, others will for sure think of something else:
Create a web server and actually serve a web site with your interface. You can code the interface yourself and communicate with your java server using ajax, you can let GWT among others do that for you. COnsider also frameworks like Struts
Create an applet which will become an embedded object in a web site. This is quickly falling out of grace, and I'd strongly discourage you from doing it, if only because of the pains of java plugins in the browser
Create an application with an interface by using AWT or Swing (which come with Java) or, and this is my personal opinion, more elegantly with SWT
It's hard to tell what will best help you without knowing more of your requirements, but if you are going web, I'd suggest you check out GWT, and if you are going desktop app, look into SWT. Also, please understand these are all well tested frameworks and my preferences are just that, preferences.

To create an interface in eclipse using java you can use swing.
In eclipse:
Create a new Java Project (File -> New -> Java Project).
Right Click on src folder and click New -> Other -> WindowBuilder -> Swing Designer -> [Application Window]/[JApplet].
Add the components that you want (buttons, textfields...).

Seems to me like your trying to graduate from console programs to GUI programs. A GUI works differently from a console program. A console program you have a bunch of loops and if statements, but a GUI program work completely differently. The main difference is that GUI programs are event driven.
With that being said, you want to choose a GUI framework, like Swing. Then decide if you want your application to be web based or desktop. An applet is more for web. If you want a desktop program, then you want a JFrame which will be the top-level container of your application.
You can learn all the components that are available to you in the standard Swing API here. IMO it seems like you need to start from the beginnging, so I would start from the very being of How to Create GUIs with Swing. You will want to pay close attention to section on Writing Event Listeners
If you do want to create an Applet instead of a desktop program, you can see the Applets, where you'll learn how to develop Applets and how to deploy them. You will still need to learn some basics though from the Swing link I mentioned.
Also, before you start using drag and drop gui builder tools, I would strongly urge you to first learn to hand code. It will work best for you in the long run.
I hope this gets you started in the right direction.

The defacto world standard GUI for all platforms is becoming Html5 and css3.
So the easiest way for you to write an interface is in HTML. You don't need an applet unless you have real specific needs like having a constant connection to the server for a chat or whatever. Anyway most of the applet reasons to exist are now resolved in standard HTML. If you want to learn a new langue, try Dart (dartlang.org)
You could use dart to have the more adaptable GUI to standards in the world
I explain why in this blog post
http://1veu.blogspot.com/2013/12/why-i-think-dart-will-detrone-java.html
Naturally even if you need to write a stand alone application with native GUI, HTML5 and css3 are still widely employed along with webkit or native code transformers like PhoneGap.

Run a Java game inside an SWF?

So, I wish to program a game in Java, but be able to post it on online video gaming websites. For some reason, most game websites do not support the use of .jar files, so I sadly cannot just publish that. However, I have seen one method that works, but I need an explanation to what it is, and how to do it. Some Java games appear to be put on an independent website, then an SWF loads the page, like a browser. For example, Runescape on Kongregate seems to run like this, despite the actual game being written in Java.
Is this a known method? Does anyone have any idea on how to do this? Please, I'd really like my game written in Java, not ActionScript. I can't imagine running Java from an SWF similar to how a browser does it is that hard. Thanks.

Runescape uses their own version of Java web start to play the game. When you first play Runescape, Jagex uses Java web start to load Java code to your computer that loads the rest of the game. That's what the update check does every time you play.
You can write your Java application so that it uses Java web start. You have to provide a URL on a web page so that the user's browser can download your code to their computer.
Your other choice is to write a Java applet. An applet is run from a web page. The web page has applet HTML to start the applet.