Spring boot back end with Swing client - java

I have a design question: I use DB + Hibernate + SpringBoot as back end in a server and use Swing clients on desktops.
I am considering for a new project the following architecture:
Back end (maybe in separate servers):
SQL DB
Spring Boot + Hibernate Java App
Front end(s):
Swing Java App
later: mobile App; Browser
I have searched a bit, but still have some doubts and feel I am missing something. I initially considered using React for front end. But this is going to take too long for me and I have lots of Swing components that I already optimized (and this my applications tend to use lots of grids with edits "in place")
I searched for Spring + Swing, but what I found was about running everything on the same JVM. I would think that separating them would allow me to (later) build a Mobile or Web front end using the same back end.
To sum it up:
create back end services with spring boot + hibernate on top of SQL db
create Swing front end that consumes those services
(later stage) mobile app to consume these same services
Questions:
Is this a good approach ? Am I seeing this the wrong way
How to "share" the POJOs between the back end and the front end? (thinking about placing the models on a separate lib); I don't mean how to transport them, I mean how to reuse them on both projects.

This is possible.
I would create the backend application with Spring Boot and access a datastore with Spring DATA. I would make services available via REST.
To access REST from your Swing client you must use a REST client of some sort. I would recommend Spring RestTemplate but there are many alternatives.
Synchronous client to perform HTTP requests, exposing a simple,
template method API over underlying HTTP client libraries such as the
JDK HttpURLConnection, Apache HttpComponents, and others.
Since you want mobile support some time in the future you could consider creating a webclient instead and making it cross platform (browser only).
To answer your two questions:
Regarding backend you will be perfectly fine as Spring Boot is a good option. As for the client I personally would not choose Swing today since it is very old and rather go for JavaFX 2 or a web client if that is an option. If you are the only developer and since you are proficient it might be a good solution for you.
You can share the POJOs from you Server for your Client as an api that you include as dependency. However it is usually not recommended to share POJOs but rather generate it on the client side or just type them. In your case if it is a small project it probably is ok. Do what is most easy for you.
I would recommend start using Maven as a build tool if you do not already.
Good luck.

Your request is perfectly valid, as you are a Swing developer and your approach is absolutely fine.
So let's draw the general picture: you're building a backend/frontend product/software.
Backend
Your backend will be a Spring application that will run on a server, let's say http://localhost:8080, serving requests to clients.
You'd probably want to create a #RestController on http://localhost:8080/api/... to expose your functions to your Swing client.
Swing client
Your client will be a Swing application running on your desktop.
To connect your client to the Spring application, you now need to implement a service in your Swing application that will call your Spring web server and fetch the resources from there.
To achieve this goal, may options exist:
Why not plain Java ? Use this tutorial to call your Spring services.
Http components from Apache are quite common.
Spring your app ! Spring API includes RestTemplate that you can use in your Swing app to call Spring backend and fetch resources for your desktop app.
As you can see, this is EXACTLY the same thing as with a website in React:
your web page is the JFrame
your JSX components in React would be your JPanels and components
you'd connect action listeners on components (JComboBox, JButton) to a service calling your Spring backend.
you'd then use the resources fetched from your Spring server to update your application state.
rince and repeat
So, be confident, your approach is correct. You'll find people ranting at you having chosen an obsolete techno but really, who cares?
(May I add, totally a pun, you've been smarter than the JavaFX guys which are now facing the segregation of javafx libraries from the core Java ;-))
And as always... happy coding !

Related

Facebook Messenger bot using Spring Boot?

Nowadays more and more chat bots are being created, as the process is relatively easy if you activate a facebook developer account, and create a facebook page for this purpose.
Probably the most popular method is to using NodeJS - Heroku, as it is explained in the following article:
https://chatbotslife.com/how-to-make-a-facebook-messenger-chat-bot-in-1hr-af6bec5e7aec#.xqgu2lb46
After a research I found that making connection with facebook IS possible via Spring boot (as explained here: https://spring.io/guides/gs/accessing-facebook/ ) but I have not found any information or - even similar to the NodeJS - method to handle a messenger conversation using a Spring Boot server.
Is it possible to request and send facebook messenger messages from Spring Boot? I would prefer that over NodeJS, as I have a system already built in Spring Boot, and it would be much easier to integrate this feature there, than creating a new service, which would be then connected to the existing one. (even if in some cases I definitely would stuck with the 'microservice' structure.)
It is possible.
Cast a glance onto that project:
https://github.com/messenger4j/messenger4j-spring-boot-quickstart-template
Though I understand your reason why you want to 'keep things together', I definitely would recommend to separate things to smaller pieces when you can, as it is a much better strategy generally.

AngularJS + Spring Project architecture

I am planning to start a project and I am looking for the best approach to make a RIA application using AngularJS.
Right know I am pretty sure of those technologies:
AngularJS (+ bootstrap CSS) for the client UI, logic and server
requests.
Spring for bootstrapping the server business logic.
Hibernate + MySQL for persistent data access
Jersey for the Restful web service API.
Spring Security for url and data protection over authentication.
The only piece I feel is not ok is that my application will not be the typical one page app, because it will be large and I want to break it into multiple one page apps, some protected and others public. To serve every index.html I want another technology like Spring MVC, making those small one page apps secure for this points, and also not allowing the access to some resources.
¿Do you think this is a good approach or you would change any of this technologies (like supressing jersey/Spring MVC redundant dependencies)?
i think that in general your aprroach is a good one, but maybe you could use the webapp generator yeoman with the JHispster, a java web app generator.
Or if you don't like the ideia you could add to your data access layer the Spring-Data-JPA, because you will avoid to write the boilerplate code.

Build an Web UI with AngularJS for a java project?

I would like to add a Web User Interface for an existing Java project I did time ago. I learned basics of AngularJS on codeschool.com courses and now I know how to send an http or REST request to get data for my web UI.
My Java project has a set of methods that elaborate some data from a local database and return integers or integers arrays.
The goal of the interface would be to show a bunch of charts and data directly from that Java project.
What would be the most appropriate way to do this? I heard of implementing REST services on my Java project but it seems overkill for the purpose and i'm totally confused by all the frameworks for this. What would you use?
Thanks everyone for your answers!
I would use SprinvMVC to provide data from server to client side.
Here is my project from which you can start and learn basics :
https://github.com/xwid/thaimaster
Basicly you should create spring controllers mapped to urls, by doing it this way, you will be able to retrive server data using angular js.
http://www.javabeat.net/spring-mvc-angularjs-integration/
If you don't want to use a full REST framework such as Jersey, another possibility would be to use an embeddable HTTP server (there are several) and handle the requests yourself. This would mean that requests to something like /myapp/ would return your AngularJS filled HTML page, and requests to /resources/* would provide with REST functionality.
This would give you a standalone Java program that doesn't need a servlet container, but it would be a somewhat hacky solution. Not production grade, but you'd probably learn something from having to handle the HTTP traffic yourself.
With the Spring Framework's SprigBoot, it's quite easy to implement a REST service and have a runnable java application. You can follow this Building a RESTful Web Service guide from spring.io. They are clear and quickly understandable.
Also if you are not already familiar, through these guides you can have a glimpse of gradle and maven as well.

Frameworks for Monitoring Application

We're starting work on a monitoring application that will be providing status for several pieces of hardware. The data will be updated on an Oracle DB by a backend process, this application will have to be developed in Java and deployed on a WebLogic 12c application server stuck behind an Apache HTTPD server.
Since the monitoring will be real-time, we'll be needing almost instant refresh of the data that was added on the database. To achieve this, I've been doing some tests with the following frameworks:
Hibernate as ORM.
Spring 3.0.5.
JSF 2.2 and PrimeFaces 3.5 with PrimeFaces Push (Uses Atmosphere).
My tests were successful and I was able to get something working quite quickly. However, I've noticed that Atmosphere has some potential that is being contained by the PF implementation, also, I don't know if this is the most lightweight solution.
Because of this, I wanted to ask you if you guys had any other approaches for this solution, i.e:
Spring MVC + Atmosphere.
Other MVC + Other Comet/WebSocket framework.
Most of the data shown will be for charts, tables and maps. The biggest limitation will be that everything must be Java compatible, since the application server won't be changed.
To summarize, my question is:
Which alternative options do you suggest for this project based on the requirements and limitations I established?
Let me know if you need additional information.
Spring 4 has good Websockets support, have a look here at the documentation. It makes possible to create a websockets endpoint, and use it in a publish-subscribe model based on the STOMP protocol.
This protocol is a messaging protocol that allows to subscribe to a topic and receive notifications, publish to a topic to all subscribed listeners or send a server push message to a single client.
Currently Websockets might not work for all users due to browser limitations, proxies that are not configured to forward the upgrade headers needed to upgrade from HTTP to Websockets, or network elements that timeout long-lived connections.
Spring 4 provides good support for this via SockJS, which has transparent fallback capabilities (to ajax, iframe) if a Websocket connection cannot be established.
All these things are needed to use Websockets in this day and age, and Spring 4 provides a complete out-of-the-box solution.
Have a look at this blog post to see how lightweight this solution is, specially if used together with Spring Boot.
If it's a frontend intensive application you might to couple Spring 4 with AngularJs, for frontend widget development. But Primefaces is a great solution, if the widgets they provide suit your needs it would spare a lot of work.

Advice on Application Architecture

I am about to build a system that will have its own engine, as well as a front end user interface. I would like to decouple these two as much as possible. The engine should be able to accept commands and data, be able to work on this data, and return some result. The jobs for the engine may be long, and the client should have the ability to query the engine at any time for its current status.
A decouple front-end / back-end system is new territory for me and I'm unsure of the best architecture. I want the front end to be web-based. It will send commands to the engine through forms, and will display engine output and current status, all through ajax calls. I will mot likely use a Spring-based web app inside Tomcat.
My question involves the best structure for engine component. These are the possibilities I'm considering:
Implement the engine as a set of threads and data structures within the web app. The advantages here would be a more simple implementation, and messaging between the web app front end and engine would be simple (nothing more than some shared data structures). Disadvantages would be a tight coupling between the front and back ends, reliance on the server container to manage the engine (e.g if the web server or web app crashed, so would the engine).
Implement the back end as a stand alone Java application, and expose its functionality through some service on a TCP port. I like this approach because it's decoupled from the web server. However, I'm not stoked about the amount of low-level networking / communication code required. I would prefer some higher level of message passing that abstracts Sockets etc.
Use an OSGi container like Spring DM server to host both the web app and engine. This approach is nice because the networking code is nonexistent. The engine exposes services to the OSGI container for the web app to consume. The downside here is the learning curve and overhead of a new technology: OSGi. Also, the front and back end remain coupled again which I dont really want. In other words, I couldn't deploy the front end on any old servlet container, it would have to be in the same OSGi container as the engine.
I have a feeling RMI is the way to go here, but again that's a new area of technology for me, and it still doesn't explain how to design the architecture of the underlying systems. What about JMS?
Thank you for any advice.
If you really want to decouple web app and engine,you can also deploy the engine in a different server and expose the API as web service calls (WS-* or REST).
If it's going to be a Web app, there's no need to decouple the processes like there would be if you had a desktop app front end and a server back end. So keep it simple.
The basis I would use (and am using for a project I'm working on currently as it turns out) is this kind of stack:
Spring 3
Web container
Application deployed as a Web application (WAR);
For persistence, either Ibatis (my preferred option) or JPA/Hibernate (if you prefer a more object persistence approach);
Your preferred choice of Web framework. There's no easy answer here and there are dozens to choose from, from the straight templating to the more componentized (JSF, Seam, etc). Tapestry/Wicket look interesting but I'm no expert in either.
A Spring container is entirely capable of launching a series of threads and it's quite common to do so. So what you'll need is a series of components that will simply be your engine. Unless you have a good reason to do otherwise, Spring beans within a Web application context is simple, flexible and powerful.
On the front end it depends on what you want. Straight HTML can be done with any Web framework. Even if decorated by some Javascript. I use jQuery for that kind of thing.
It only gets a little different if you want the front end to look like a desktop app (a so-called "rich" UI). For this you either need to use the Google Web Toolkit ("GWT"), possibly a component Web framework like JSF (although I tend to think these get real messy real fast) or a Javascript framework like ExtJS, SmartClient, YUI or the fairly new Uki.
You'll decouple your UI if you write your back end as services, and establish an XML or JSON message format to pass between client and services.
All the rest of cletus's comments can hold true for the back end, but the client can be blissfully unaware of it. It can even be a .NET implementation for all it cares. The focus is on the use cases and the messages, not the back end implementation.
This can also be useful in those instances when you use a non-HTML based UI (e.g., Flex).

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