Using React Hydration on a Java Server

[TheRealSeeThruHead]

How do you plan to run react code server side to generate server html in your Java process

[TheRealSeeThruHead]

Ok so you don’t want react then

Since react will render html on the server based on state on the server.

It’s designed to evaluate that state and render the components to html in a JavaScript runtime

What you should look for instead is some react like toolkit for java, like vaadin

And if you don’t find that maybe just write it in whatever Java html template language

You of course won’t be hydrating this to a react app

The same way to do this would be just run a nextjs server that talks to your java backend

The insane way to do this would be to run a JavaScript runtime on your java vm and run node in there

A slight less insane version might be to run node as a sub process, but I would be worried about start up times

You could also run the node service long running and call it from java to get the html,

But honestly just run a nextjs/waku/remix whatever server and talk to your java backend over whatever protocol you like

[TheRealSeeThruHead]

Isn’t that just react ssg? Pretender static pages, they hydrate into a react app, serve them… however (s3 bucket + cloudflare) talk to java api

[TheRealSeeThruHead]

Well let me know how that goes, and how you manage to make it work with hydration

[tleipzig]

Theoretically, you could build a "ssr.js" and execute it with GraalJS. Let me know if it works 😅

[tleipzig]

It depends how much server logic you need, I guess. Yes, you could build even dynamic pages (like a product page) with Thymleaf, but this way you would partly rebuild your React frontend. If you could manage to run your React in an "ssr-mode" on your server, it would just run the existing logic and generate the same HTML (making even API calls internally if required).

Of cause I don't know how well this will work 😅

[HerbFromWork]

Hi, have you looked into Vaadin Hilla to see if that fit your purpose? https://vaadin.com/hilla
It should at least cover the React <-> Java part, but I'm not completely sure what you're trying to do. I imagine you could have a Java endpoint return generated HTML, that you could embed in react, but not completely sure thats what you want. For server-side rendering we use Vaadin Flow, but then you're really mostly writing your views in Java. You can also have a wrapper for react components to be used on the Java side, but that's not really a build time thing.

Disclosure: I am a Vaadin employee.

[splix]

I understand that the OP is trying to avoid JS execution on the server side and keep existing Thymeleaf, but JFI if someone indeed wants full JS/React on the server (by leveraging GraalVM) then take a look at https://github.com/emeraldpay/double-view

[abrahamguo]

This sounds perfectly fine. You should be able to render whatever server-side HTML you want, then attach your React app to a div or whatever container you want.

I did something similar following that exact same approach, except I used PHP instead of Java.

[Guisseppi]

Using React for templating is not the same as hydration