from Hacker News

Java in the Browser

by krisgenre on 8/23/22, 11:12 AM with 108 comments

• by StevePerkins on 8/23/22, 1:02 PM

  I don't know if the performance is terrible in general, or if the demo site is getting crushed by HN traffic at the moment.

  If it's the former, then this is completely useless. If the latter, then I suppose it COULD have some use cases for internal tools and dashboards, in small to mid line-of-business shops that don't have many front-end developers on staff (i.e. basically a competitor to .NET's Blazor).

  The REALLY interesting thing here is that this product isn't licensed per-server, or per-CPU, but rather "per 8GB block of RAM"! Look, I love Java. It's helped me build a great career, build a future for my family, and I really do believe that it's the best developer experience out there for the server-side. However, the idea of licensing a Java-based product by its memory usage makes me laugh out loud.

• by TeaVMFan on 8/23/22, 2:00 PM

  Actual Java in the browser (working, fast, passes Lighthouse) with TeaVM:

  https://blogs.oracle.com/javamagazine/post/java-in-the-brows...

  For example, try this 5-letter word game:

  https://frequal.com/wordii/

• by TacticalCoder on 8/23/22, 1:01 PM

  Anyone remember that Java applet in the nineties where there was some 2D wireframe "animal" moving in a rectangle and there was, IIRC, a tiny circle at each joint and you grab it and move it and it'd move the thing around / distort it. It was the first "serious" Java in the Browser I remember. It was all black & white. Maybe some HNer (not an HNer back then obviously) wrote it back in the days?

• by jeffreportmill1 on 8/23/22, 2:00 PM

  Well this isn't helpful for those of us that care about Java in the browser. In any case, JPro is really more "Java projected in the browser" (or like twitch/remote-desktop). It's a shortcut with significant drawbacks. I'm more a fan of TeaVM, CheerpJ, J2CL and JSweet.

  https://reportmill.com/snaptea/

• by adrianmsmith on 8/23/22, 12:20 PM

  I have looked around the website and I really have no idea what this is. I feel their marketing and doc could do with a bit more explanation if it's intended for devs. Is it like applets in that there is a runtime in the browser? Or more like GWT which compiles Java to Javascript?

  Also, the website which is apparently created with the technology, is incredibly slow, at least for me.

  And the website doesn't give useful loading indicators, e.g. click a link, nothing happens, or go to the doc section and navigate and lots of empty screens (presumably while the content is loading). No browser loading indicator, nor spinner in the content.

• by pavlov on 8/23/22, 12:30 PM

  Java in the Browser, February 1996 edition:

  http://www.antipope.org/charlie/old/journo/netscape.html

• by ksherlock on 8/23/22, 2:13 PM

  There was also Browser in the Java - HotJava, Sun's circa 1996 web browser written in Java.

  https://en.wikipedia.org/wiki/HotJava

• by specialist on 8/23/22, 12:27 PM

  Interesting. Runs app on the server, does final rendering of the UI's scene graph on the client (within the browser).

  It's not clear from skim reading if the client side rendering is implemented with the DOM or a canvas element.

  I've always thought it'd be hysterical to use canvas. The whole browser just to hoist a client side frame buffer. X-Windows reinvented.

  FWIW, JavaFX is so close to The Correct Answer™. Definitely the best effort thus far. (I haven't used SwiftUI yet.)

• by opvasger on 8/23/22, 12:45 PM

  it's sort of funny - I expect Java in the browser not to work well (as it didn't, historically)... And sure enough - the site returns a 502 error :P

• by floriankirmaier on 8/23/22, 4:36 PM

  Some notes from the developing company:

  First of all, sorry for the bad performance in the first hours after this post. The server isn't setup up for a big traffic peak. It was way higher than we are used to. To improve the performance, we increased the memory.

  Many of our demos represent heavy business applications. Especially the "FlexGanttFX Demo" is a good example.

  With JPro the Application itself runs "logically" in the server, and the rendering happens with javascript in the client.

  Usually, the performance is very fast - and the architecture is not noticed by the user.

  Feel free to ask any further questions.

• by samwillis on 8/23/22, 12:37 PM

  Site appears to be down, there is an archive here from June 2020:

  https://archive.ph/mJDAT

  Newer archive on IA from March this year doesn't load anything:

  https://web.archive.org/web/20220316200857/https://jpro.one/

  However has source code including:

     <jpro-app loader="none" href="/app/default" fxcontextmenu="false" fullscreen="true" nativescrolling="true" fxheight="true" snapshot="auto" userselect="true"></jpro-app>
  

  So assuming there was a newer site that had some sort of embedded Java thing...

  By the sounds of it, it was a demo where the website ran as java on the server, rendering and pushing to the browser in real time? Guessing it couldn't handle HN traffic...

• by gabereiser on 8/23/22, 3:44 PM

  So I guess we’ve come full circle now? Java was the first to run in the browser (via applets).

• by oaiey on 8/23/22, 1:04 PM

  I do not know. .NET created with Blazor a modern Applet tech stack based on WebAssembly and HTML.

  Would not Java be able to do the same and just port the applet API onto a Canvas? Would not that reactivate a whole existing ecosystem?

• by manholio on 8/23/22, 1:10 PM

  Now someone please compile a real JRE into WASM and do it right, so I can revive applets with a simple embed. There are loads of old applets that have huge historic and technical value which are becoming harder and harder to use.

  Example: https://www.grc.nasa.gov/www/k-12/rocket/ienzl.html

• by bschwindHN on 8/23/22, 12:49 PM

  This is very advanced satire.

• by invalidname on 8/23/22, 1:08 PM

  Site is down but it seems like server side rendering which is pretty terrible. There are better solutions for Java developers such as teavm one which Codename One built the web UI support. It supports both web assembly and plain JS. The latter has the advantage of smaller size.

  Transpiles Java threads into async/await calls. Pretty cool stuff.

• by mondainx on 8/23/22, 1:51 PM

  WASM really is the way to go for this kind of thing IMHO; I love me some Java and have for decades, but Applets were painful, especially when hooking in native code. HN seems to have killed the demo, I'll have to remember to come back later when the hoopla dies down.

• by cryptonector on 8/23/22, 4:09 PM

  Java in the browser used to be called applets, no? Anyways, it failed, thought that probably had a lot to do with: JavaScript being more accessible (still is) and the security model for applets (JAAS) being rather lame (it was, and still is, and it continues to exist in spite of applets being gone because JAAS metastasized).

• by nice_byte on 8/23/22, 8:50 PM

  I tried the demo website - it takes seconds to respond to clicks, even on an M1 mac. I'd rather set myself on fire than use software built using this technology.

• by elwell on 8/23/22, 6:24 PM

  "Your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should." - Dr. Ian Malcolm

• by butz on 8/23/22, 3:16 PM

  Time to update "3 Billion Devices Run Java" message.

• by robertwt7 on 8/23/22, 12:31 PM

  there's a price for this??

  I'm not sure what this is by looking at their homepage, is this similar to WASM?

  also who would pay to develop something for the web anymore?

• by paultopia on 8/23/22, 7:45 PM

  Proposed subtitle: "the original sin"

• by Joyfield on 8/23/22, 6:55 PM

  Gb != GB.

• by stall84 on 8/23/22, 2:28 PM

  wait a minute .. LOL!!!

• by peterkelly on 8/23/22, 1:15 PM

  I thought we tried this already...

• by Koshkin on 8/23/22, 12:36 PM

  Looks like it’s a custom webserver.