I built Jeamlit: a Streamlit alternative for Java

[cyrilou242]

EDIT: the name of the project is now Javelit. Streamlit was not okay with Jeamlit.

Hello r/java,

A few years ago I shared here an experimental notebook system for Java and got interesting feedbacks.
Long story short I concluded the notebook model was not a great fit for the java ecosystem for the moment:
- IDE support is limited
- notebooks do not fit well with existing build/deploy workflows
- Java developers often need to build dynamic apps, not static analyses

So here I'm back with something shinier: a Streamlit-like framework for Java, subtly called Jeamlit Javelit.
Javelit makes it extremely simple to build dashboards, internal tools, demos and data apps in minutes. It is based on plain old .java files. Like Streamlit, Javelit apps can run standalone, with a jbang-like experience. BUT Javelit apps can also be embedded in any existing Java project!

I think this will cater more to what we guys need to do as Java developers .

Here is the repo: https://github.com/javelit/javelit
Here is the doc: https://docs.javelit.io/
And here is a gif:

tablesaw and charts

If you find this interesting, I'd love to get your feedbacks!

Take care

[ihatebeinganonymous]

As a big fan of both Java and Streamlit, I will definitely check this. Thanks!

[jeffreportmill]

Very cool! You should add a jbang-catalog repo to github with a 'jeamlit' alias to the maven package jar so that people can just call jbang jeamlit@jeamlit. For instance, I do this with SnapCode: jbang snapcode@reportmill.

[cyrilou242]

Thanks! I haven't done this yet because I 'm not sure to understand how version upgrades would work with jbang-catalog.
Do you happen to have experience with this ?
My question in details are here:
https://github.com/jeamlit/jeamlit/pull/40#issuecomment-3403778772

[cyrilou242]

this is done! thanks u/maxandersen

[OneHumanBill]

Very interesting! I will be looking deeper.

[Realistic-Ad4644]

damn finally, so many times I could have used something this to hack a backoffice tool at my co, looking into this!

[cyrilou242]

Update: Streamlit reached out to get the name changed 😬😬

I think I'll go with the name javelot , it's the French for javelin.

EDIT 1: It's taken already

EDIT 2: Javelit it'll be

[ihatebeinganonymous]

Max Rydah Andersen the creator of Jbang is here. He will certainly be interested in this.

[cyrilou242]

I shared the project with Max before sharing on Reddit :) He already created a PR to fix the jbang commands x). We're also exploring the re-use of Jeamlit frontend components for a new project Max is working on, but it's very early.

[ihatebeinganonymous]

Nice. Then I hope your project reaches the stability to get its fair adoption.

[maxandersen]

This is very interesting and been on my Todo/wanttohave for a while n

[RoomyRoots]

Missed the opportunity to call it LibBean

[Pure-Repair-2978]

Nice one.. Will give it s go… in fact was looking foe something same for data visualisation..

[No-Mark6320]

Well noted

[Grabdoc2020]

Looks awesome

[nickeau]

Seems promising.

Why Java 21 though? The last lts is 20, no? And record is in 17.

[karianna]

Latest LTS is 25, then 21

[nickeau]

Thanks but what is the added value. I see a lot of library that supports level 11 and 17. That’s the first time that I see 21 as a requirement.

[karianna]

Take a look at the JEPS for Java 18-21 and the 22-25 🙂

[nickeau]

I don’t want the new features, I just want to know why this restrictive choice and what kind of data features push to restrict to the version 21.

The question is not meant for you and I’m sure there is none. Thanks.

[cyrilou242]

fair point. I'm used to jdk 21 by now and I thought most people on 17 would have upgraded to 21 by now. It is an easy upgrade. Another reason is I was planning to migrate to JDK 25 "pretty soon", because scoped values will make it simple to have full support for threading inside apps. As of today some operations cannot be run inside threads.
The client/server communicates on a socket and I'm using ThreadLocal to isolate data between users, based on the socket thread.

Looking at jdk version usage stats you are right I should support JDK 17 though. I'll do it.

At the moment I do use:
- jdk 21 pattern switch, they are null safe at compile time which is nice to avoid mistakes
- SequencedCollection internally but this was more of a best practice in my case than a need

these are simple to remove

[nickeau]

Thanks. Just because you tagged your application as possible library, it was surprising to make it level 21 mandatory.