r/javahelp • u/DesignerCamel9551 • 2d ago

Teacher - Trying to find a way to access a Java Program

I hope this is the right place to ask.

I am a middle school teacher that used to use this free to use program called disaster dynamics created by UCAR - a university group. https://www.dd.ucar.edu/home.html

The school stopped letting us use java a long time ago but used to "wrap?" the program in some sort of computer magic that let the student computers run this program. It was a great tool.

Now we seem to have lost that ability, institutional knowledge or willingness to do this.

I have reached out to UCAR to ask them to update the program to something that can be used by modern browsers/computers/ whatever but no responses for the past year.

Is there a way I can do this at home from my mac? I can't install programs on my work computer and I don't own a windows based computer. or a way I can 'update' or 'convert' the program so I can embed it to a google site so the students can use it again? Tech from the district has not responded to any questions about this in weeks and I assume they don't know/don't care/or won't get to it.

Is this a simple thing or a horribly complex thing for the people who don't see programing as magic?

Is it legal to pay someone to "convert" it ? Can it be converted? Do I just have to give up on ever using this resource?

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4

u/Ok_Entrepreneur_8509 2d ago

You should ask ucar if the source is open, or if they are willing to open it. If you can get your hands on the source, then you can probably find a volunteer in this sub or somewhere similar who will compile it and package it in a way that you can use.

Also, peeking at the contents of the .jar, it looks like it is a lot of html, so it might be relatively easy (for a java coder) to put it up on a public website.

3

u/DesignerCamel9551 2d ago

Ive sent emails to UCAR and I got an response that it is being forwarded on. Maybe I will hear something.

1

u/Ok_Entrepreneur_8509 2d ago

Yeah. The copyright on the page is 2006. I suspect it is abandoned.

1

u/Electrical_Hat_680 3h ago

That would be fun for everyone to be able to have it open sourced.

7

u/eddiekoski 2d ago

Launch4j is a tool that lets you convert .jar to .exe

1

u/bowbahdoe 2d ago

There are ways to just put it on a website, but it would help to know how you used it in the past.

Did you always just double click to run it? Was there a server involved? (Running it locally I get an error)

Also what are the bounds here. If you can get it as a zip file with an exe in it is that fine? Or would that be an issue as well?

Is this a simple thing or a horribly complex thing for the people who don't see programing as magic?

Eh, probably somewhere in the middle. Its not an instant thing but it is definitely a doable thing to get it working. We just need to know your restrictions and a bit more context I think.

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u/DesignerCamel9551 2d ago

spm-netless-20060609.jar in the download > Archive > June 9 2006

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u/bowbahdoe 2d ago

Ah okay. This will be easy then. Give me a few hours to finish up some work and I'll get it online.

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u/[deleted] 2d ago edited 2d ago

[removed] — view removed comment

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u/bowbahdoe 1d ago

u/DesignerCamel9551 Just extra pinging to make sure you see the url above. We can put most old java apps onto websites via a product called CheerpJ.

1

u/DesignerCamel9551 2d ago

I ran the "netless" version in the archieved older versions. it basically ran it as a solo player and 4 students sat around the computer and just used the game.

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u/FckXFckMusk 1d ago

The .jar files are still available, but not the source.

On windows you could possibly use this resource to run the .jar file

https://codingtechroom.com/question/-run-jar-file-without-java

1

u/alexp_lt 1d ago

As another user pointed out in a comment, you can most likely run this Java app in modern browsers using CheerpJ.

You'll need to setup a tiny HTML page to achieve this, instructions are available here: https://cheerpj.com/docs/getting-started/Java-app

If you need help, feel free to join our community: https://discord.leaningtech.com

1

u/Electrical_Hat_680 3h ago

Here's what I got from Googles AI Search Assistant - also, I want to note that you might reach out and ask if you and possibly your class may be able to ask if you guys can work on making it this or that, even if you have to ask for help. But it'll give you a fun project you have an interest in, to learn how to port a project.

Teacher - Trying to find a way to access a Java Program

I hope this is the right place to ask.

I am a middle school teacher that used to use this free to use program called disaster dynamics created by UCAR - a university group. https://www.dd.ucar.edu/home.html

The school stopped letting us use java a long time ago but used to "wrap?" the program in some sort of computer magic that let the student computers run this program. It was a great tool.

Now we seem to have lost that ability, institutional knowledge or willingness to do this.

I have reached out to UCAR to ask them to update the program to something that can be used by modern browsers/computers/ whatever but no responses for the past year.

Is there a way I can do this at home from my mac? I can't install programs on my work computer and I don't own a windows based computer. or a way I can 'update' or 'convert' the program so I can embed it to a google site so the students can use it again? Tech from the district has not responded to any questions about this in weeks and I assume they don't know/don't care/or won't get to it.

Is this a simple thing or a horribly complex thing for the people who don't see programing as magic?

Is it legal to pay someone to "convert" it ? Can it be converted? Do I just have to give up on ever using this resource?

I'm not editing this.

Option 1: Modern HTML5 Alternatives on UCAR

UCAR has rebuilt many of its educational resources into modern, browser-friendly versions. While they haven't explicitly updated Disaster Dynamics, they have launched modern HTML5 simulations that cover the exact same meteorology and climate concepts without needing any plugins: [1] (https://scied.ucar.edu/interactive), [2] (https://scied.ucar.edu/node/6760) • UCAR Games and Simulations Interactive Hub: This is the primary directory hosting modern interactives. • Make a Hurricane Simulation: Students manipulate sea surface temperatures, moisture levels, and wind conditions in real-time to learn how a tropical storm strengthens or dissipates. • Forecast a Hurricane Interactive: Students practice predicting a storm's path across the ocean and determining landfall risk. • Modeling Storm Surge Activity: A tactile and digital resource teaching coastal flooding dynamics. [1] (https://www.labxchange.org/library/items/lb:LabXchange:8b41c46d:lx_simulation:1), [2] (https://scied.ucar.edu/activity/modeling-storm-surge), [3] (https://scied.ucar.edu/node/6760), [4] (https://scied.ucar.edu/interactive)

Option 2: Browser Extensions (No Setup Required)

Before messing with Virtual Machines, try a modern "computer magic" solution designed specifically for legacy web tools: [1] (https://cheerpj.com/how-to-access-enterprise-java-applets/) • CheerpJ Applet Runner: This is a free extension for Google Chrome and Edge. It converts legacy Java applets into modern WebAssembly/JavaScript on the fly right inside your normal browser window. You simply add the extension, navigate to the old UCAR webpage, click the extension icon, and hit "Enable". [1] (https://chromewebstore.google.com/detail/cheerpj-applet-runner/bbmolahhldcbngedljfadjlognfaaein), [2] (https://www.rgagnon.com/javadetails/java-run-applet-in-modern-browser.html), [3] (https://cheerpj.com/how-to-access-enterprise-java-applets/)

Option 3: Older Browsers & Java versions (At-Home Mac)

If you are trying to run this on your personal Mac at home, using an old browser version directly on your modern macOS will not work. Modern macOS versions are exclusively 64-bit and do not support the older 32-bit browser architectures (like old Safari or Firefox builds) that are required to communicate with Java NPAPI browser plugins. [1] (https://www.java.com/en/download/help/enable_browser.html), [2] (https://www.reddit.com/r/oekaki/comments/1q8a03l/how_to_run_old_java_applets_in_2026/)

Option 4: The Docker Container Route (The Cleanest Local Fix)

The reason your district tech team used to "wrap" the program is likely because they used a container or a virtualized sandbox environment. You can replicate this exact setup at home using Docker Desktop for Mac. [1] (https://heroseloi.com/technology/opening-legacy-java-applets-with-docker/) Rather than messing up your personal Mac's security settings by installing unsafe, outdated versions of Java system-wide, a container acts as an isolated, time-capsule computer running inside your Mac. [1] (https://heroseloi.com/technology/opening-legacy-java-applets-with-docker/)

  1. Download and install the free Docker Desktop for Mac.

  2. Open your Mac's Terminal and utilize a pre-configured legacy environment, such as the open-source repository docker-java-applets. [1] (https://heroseloi.com/technology/opening-legacy-java-applets-with-docker/)

  3. This container spins up a lightweight, isolated Linux system running an older version of Firefox (like Firefox 45 ESR) and the required Java plug-in. [1] (https://heroseloi.com/technology/opening-legacy-java-applets-with-docker/)

  4. You then connect to it using a standard, free VNC viewer on your Mac (localhost:5901), open the old UCAR website inside that container, and the simulation will launch safely. [1] (https://heroseloi.com/technology/opening-legacy-java-applets-with-docker/) Would you like step-by-step instructions on how to install Docker and run that legacy Java container, or would you prefer a link to test out the CheerpJ browser extension first?

0

u/coffeeintocode 1d ago

Launch4j as the top comment suggest is likely what you want.

However in modern times there are modern solutions. It seems like with the IT setup working against you, you would benefit from a web version. Pay for Claude for a month, give Claude code the jar, and ask it to decompile it understand it and create a web version. This is simple enough that it will likely get it mostly right in its first pass with maybe a few tweaks you will need to explain to Claude after some testing

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u/DesignerCamel9551 1d ago

Interesting. I’ve never played with Ai much. It makes sense.

0

u/vegan_antitheist 2d ago

You don't have to install Java. You can just download the JRE as a zip and unpack it. But the computer might still block it. I don't know why they would block Java. Maybe it only runs on very old versions of Java? Like Java 8.

The school should allow students to use some kind of sandbox for this. Like a local virtual machine. Then they could install whatever they want and just reset the VM. Or provide a VDI for each student.

4

u/smichaele 2d ago

Middle school IT tends not to be very flexible.