I have a ajax frontend for my java backend, and to make things work with the crawls and HTML5 pushState I going to use HtmlUnit to process the javascript in every first request.
I can make a workaround with a Filter to not use HtmlUnit trying to reduce the server load.
Regardless of browser compatibility, which is best for the server?
After a lot of research and test I can tell that process heavy javascript applications on server side ins't I good idea, HtmlUnit is the best tool around and it doesn't do the job very well, so if your requirements are to support clients that doesn't support javascript, so go for PHP or some other server side script language or maybe JSF.
I my case, I have a Back-end in JAX-RS and I manage to support HTML5 pushState without process the javascript on server-side and assume that the client process javascript, HtmlUnit still in use for enable crawlability.
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We have an application in pure JSP/JQuery which we are trying to move to ReactJs for maintainability. One of the benefits of ReactJs I am seeing is server side rendering. However, all the examples I have seen of server side rendering utilize Node.js as a server side. We are currently using Tomcat and not so much inclined to deploy node.js just for server side rendering.
I have considered few alternatives such as using Nashorn (http://winterbe.com/posts/2014/04/05/java8-nashorn-tutorial/)
However, Nashorn doesn't seem to be production ready.
Has anyone deployed React.js with server side rendering on Tomcat on production?
Trying to render a Javascript app serverside without NodeJS is an excellent way to torture yourself. Trying to run javascript inside a jvm is even worse. I would recommend against it.
It is possible to render the complete client server side using PhantomJS (which technically runs without Node) or even using xvfb and Chrome on *nix. All have been done, with various degrees of painful debugging.
Running the javascript inside tomcat itself is rather unusual… I can't see the point other than "because we can". My best guess is that nobody is doing that in production.
Why not take a step further with server-side rendering and make real-time single-page web applications in reactive style without Node.js in plain Java language?
The Reactive Server Pages project uses the approach similar to the Elixir Phoenix Live View or Scala Korolev frameworks.
Motivation:
Responsive web UI in familiar Java, no client-server APIs, no JS
frameworks and npm dependencies management needed;
Lightweight SSR generated almost plain HTML page to be SEO friendly;
UI components are regular Java classes;
Brings application rendering workload and UI logic from a client's browser to the
server, your code always stays on your server;
Debug UI code as any normal Java code;
Built with Java web standards, currently runs on Jetty, but in
theory, should work on Tomcat as well.
I am relatively new to web development, but I have some C++/Java experience. I have got the following conversion to do:
Current:
Desktop Application (Automation Software) developed in C# that communicates with remote PLC (Controller that overlooks different sensors in realtime) using TCP Sockets over the Web.
My Idea:
Convert the application into a server side software that will still communicate with the PLC over TCP/Socket. And use a browser to operate it, so the remote site can be monitored and controlled from any computer in our Intranet (possibly Tablets in the future).
Motive for doing it:
We had a computer fault which left the operators without control.
The new app:
I am planning on writing the server app using Java and OOP (so far no problem). And use HTML/CSS/Javascript for the WebApp and AJAX to update the page.
But I am still lost at how can I transport all this data between them in a proper and decent manner. I have read about SOAP and JSON in this Post. Although, I am not sure if I need to use them at all, is it a good solution to use either JSON or SOAP? Or is there any other solution that you may recommend?
Cheers,
Leo
If you consider skipping the development work to convert your app into a server-side software and just go for a third party solution, I suggest you take a look to Thinfinity VirtualUI.
"...offers a GUI remoting solution for in-house Windows desktop
developments, allowing them to be delivered as Windows/HTML5 dual-platform applications
simply by adding one line of code.
These Windows applications can keep their standard desktop environment behavior and,
alternatively, be accessed remotely from any modern web browser in a multi-user,
multi-instance fashion when hosted on a Thinfinity VirtualUI Server environment."
https://www.cybelesoft.com/docs/thinfinity_virtualui_whitepaper.pdf
SOAP is for defining public APIs that are published on the internet for other people to use, which does not seem like your use case. It is not particularly awesome to have to deal with it from inside a browser either, although there are javascript SOAP-client libraries. There is also going to be a fair bit more overhead on the server side parsing and validating XML than de/serializing between JSON and POJOs.
JSON is much easier to deal with in a browser, being natively understood and all that. Everything you need is built into the core of jQuery, no dependence on plugins that may have unknown levels of future support.
I was looking for real information about this, I am working some system on Java EE, I worked all my life on web, now I am getting into systems, my boss told me he makes javascripts works from "server side" to manage polls and stuffs, still I didnt think was right and I told him I thought javascript was only executed client-side, still seems like its right, I found both information about saying it is possible and it is not, anyone has some valid answer about this? and if yes, how is this possible?
Thanks!
You can indeed execute JavaScript on the server-side with third-party packages like node.js, Mozilla Rhino, or similar.
However, it's unclear to me from your description whether he wants you to actually execute JavaScript from the server-side, serve JavaScript content from the server-side, or use AJAX to make remote-procedure calls to server-side code.
The scripting API is in the javax.script package available in the Java SE 6 platform.
Refer Link :-
http://java.sun.com/developer/technicalArticles/J2SE/Desktop/scripting/
You can execute javascript on server side too which means that develop server centric code on server side for etsblishing connection, serving HTML files etc.All these things can be done on using server side javascript.There are so many frameworks that are used to achieve this.The main objective of running serve side javascript is to execute server side functionalities.One such example is maintinaing long-lived connections with the client.
Nod.js is such a framework which is used to implement the above said functionality.Apart from this, there are other server side javascript frameworks as well.RhinoJS is can be used to execute execute javascript in server side when running in a Java Virtual machine.
However,the idea using the server side javascript frameowork will vary depending upon your requirements.
The company I work for has a powerful Java based server component framework for interacting with special control systems.
We have a UI framework but this is also Java based. A customer can use a Java Applet to access control information etc.
I've recently started working on a rich JavaScript API to access this control system information remotely. It's currently a prototype. It's nice because anyone who's familiar with JavaScript can access our Components remotely. So far it works really well. I've written some prototype applications that use this API. This gave me an introduction to jQuery - great! I've also added the ability for the JavaScript API to make RPC calls to Java as well as a session based Component architecture for when you really need something held on the server.
So far so good. I have to admit though that I'm not really a 'web developer'. I've never used Structs, Spring or any of the MVC based architectures for serious Enterprise based web development (I AM very familiar with design patterns though). My background is application development.
I'd like to know from the pros whether this is the right approach or whether I'm missing anything. Someone I work with has created a really neat Server Side Include architecture. However, I'm wondering now whether this is really necessary? After, I think I can create just about anything using my JS API and jQuery. Should I consider any other 'server' based architectures in this new age of open web apps?
As far as browser support goes, I'm not concerned about the older generation of browsers (please no lectures here, the old technologies we've got will do for IE6 and alike).
By using this open client side technologies, I'll be able to write sophisticated open web apps. Very little server side code will be needed in reality because of my API. I'll be able to take advantage of HTML 5 features etc. But am I missing anything? Should I be considering other server side based Java technologies like Server Side Includes? Am I too client focused?
Well there are four ways to create modern RIAs: HTML5/Javascript, Java Applets, Flash/Flex and Silverlight. Only the first two are open.
Applets are a nuisance and not really liked by people. Personally I'd go with HTML/Javascript.
Since you are a Java shop I'd recommend going with GWT for the following reasons:
It's open source with business-friendly license.
It creates minimum-size browser-optimized javascript.
It's actively developed and used by Google. This is a guarantee that it'll be supported for some time.
There are a lot of developers with knowledge of it.
It has good documentation and very active user group.
I'm sure there are many opinions on this, but my take is that with HTML5, faster Javascript interpreters, client side persistent storage, etc. it makes it pretty compelling to put all the UI application login in the client (browser), and just use some form of RPC (with JSON serialization) to the server. Therefore templating engines, SSI, or any server side generated markup is no longer required for interactive applications. It's still fine for semi-static documents. For that I use sphinx document generator.
Fast-forward two years, and you now have TodoMVC at your disposal to help answer this question. GWT is still mentioned, though as far as server-side technologies go, The Holy Grail is probably what you're looking for to maximize code reuse on client and server.
I want to screen-scrape a website and for that I want to use Http, Socks4 and Sock5 proxies. So my questions are as follows:
Is it possible to use these proxies through Java without using any other external API? For instance, Is it possible to send a request through HttpURLConnection through theseproxies?
If it is not possible, then What other external APIs I can use?
I was doing it by using a headless browser provided by HtmlUnit but it takes time to load even simple webpages, so could you please suggest me other APIs (if any) that provide headless browsers that are fast in loading webpages. I don't want to open webpages that contain heavy AJAX or Javascript code. I just need to click on the forms button through the headless browser.
Is it possible to use these proxies through Java without using any other external API? For instance, Is it possible to send a request through HttpURLConnection through these proxies?
Yes, you can configure proxies by either using (global) system properties, or using the Proxy class, or using a ProxySelector. The two later options are available since Java 5 and are more flexible. Have a look at Java Networking and Proxies as mentioned by jarnbjo for all the details.
I was doing it by using a headless browser provided by HtmlUnit but it takes time to load even simple webpages, so could you please suggest me other APIs (if any) that provide headless browsers that are fast in loading webpages. I don't want to open webpages that contain heavy AJAX or Javascript code. I just need to click on the forms button through the headless browser.
Unfortunately, the first alternatives I can think of are either HtmlUnit based (like JWebUnit or WebTest) or slower (Selenium, WebDriver - that you can run in headless mode). But maybe you could try HttpUnit if you don't need advanced JavaScript support.
Yes, that is possible. You can find the configuration options for different network proxies here.