I'm starting to study GWT now, and have a very general question, I could maybe teach myself with a little more experience, but I don't want to start it wrong, so I decided to ask you.
I always develop using JSF, having separate packages for beans, controllers and managedbeans.
However, as the GWT uses RPC, I will not have managedbeans, right?
So, GWT automatically handles user session for me, or do I have to do it myself?
What is the best package structure for the project?
It is best to use RPC, or create a webservice and access the webservice in GWT?
It's hard to host the application on a tomcat server?
Is there a test saying which server is faster for GWT?
Thank you.
However, as the GWT uses RPC, I will not have managedbeans, right?
True, GWT RPC uses POJOs.
So, GWT automatically handles user session for me, or do I have to do it myself?
GWT is pure AJAX APP - client code (normally) runs in one browser window (similar to gmail) and does not reload the web page. This means that the application state is always there - no need for sessions (as a means of saving state). You still might need sessions for user authentication, but this is usually handled by servlet container.
What is the best package structure for the project?
Three packages: client, server and shared. Client for GWT client code, server for server (also RPC) code and shared for POJOs that are used by both client and server.
It is best to use RPC, or create a webservice and access the webservice in GWT?
Go with GWT-RPC or (better, newer) with RequestFactory.
It's hard to host the application on a tomcat server?
It's straightforward: GWT client code is compiled to JS/html and is hosted as any static content. RPC server code is just Servlets - normal web.xml registration.
Is there a test saying which server is faster for GWT?
No clue, but IMHO does not matter, because most of the latency will come from database and network.
Also have a look at http://code.google.com/p/gwt-platform/
This framework is really great and follow all suggested best practices(e.g. MVP) by google and give you as well great support for gin, gwt dispatcher, website crawling, history with tokens, code splitting via gwt async etc.
If you want to set up a good project structure try to use the maven gwt plugin(http://mojo.codehaus.org/gwt-maven-plugin/) it helps you a lot with setting up an initial structure and manage your build process.
Related
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 !
Im newbie in java.
I want make a web application (like a remote controller) for 3rd party server(via xml api).
I think to make a java applet for user gui and a service for parcing xml to (and from) 3rd party server. Whole app will run on separate server with apache.
Is it correct way in general or i need change my concept?
And I need advice how to make communication between web user gui (applet) and service, that parcing xml, on same host? Through or make it in one application with different threads?
Applet? So 1998.
Web UIs in browser speak HTTP to web services now. Applets are NOT the way to go.
IF you deploy on a Java EE app server or, better yet, Spring Boot, all that threading stuff will be taken care of for you.
It's not for newbies. By all means attempt if you want to learn; get some help if this is real.
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.
Ok, this is the scenario: I've developed a webapp running Java at backend, everything is working pretty well, but now I have to integrate a PHP module (boss requirement) within the whole system.
So, I need to know if both backends can co-exist in a single application and how can I accomplish that.
Yes, you can do it using GwtPhp.
Unlike most of the other frameworks, GwtPHP is a framework for both client and server part. Server part uses PHP 5 - the most used web scripting language today.
It does not sound as if your boss is being reasonable!
There are some possibilities, though:
You could have the server-side entirely in PHP. Obviously you'd still have Java for the client-side because GWT requires it, but GWT can communicate via HTTP to any type of server using XML. You just can't use GWT's RMI-like interface if it's not a Java server.
Alternatively, you could have a separate PHP layer in your app, and the server-side Java itself can call it using HTTP.
Finally, (and more difficult, and experimental) there is a project to allow PHP to run in a Servlet Container, which may give you the ability to mix Java and php: see http://www.php.net/manual/en/intro.java.php
Two things spring to mind.
1) If the PHP app supports JSONP you could run it on a separate server and interact with it that way.
2) Stick the servlet container behind apache and proxy to the servlet container using something like the AJP connector. This would mean that apache forwards the GWT requests to tomcat/jetty whatever and serves the PHP itself.
currently i have an web app build with Strus2 and Spring (IoC, Transactions), and i want to split this into 2 apps; one client which will contain only the web part and one core services that will be accessed via webservices and/or rmi.
I have a dilemma in what technology should i use for "glue", because i like the fact that webservices can be accessed by any clients (php,.net,...,mobile), but as i understand java rmi is faster then webservices.
I was thinking to expose the functionality via webservices and rmi in the same time... but i do not know how to do that.
Also in my current app i have a ajax action that is executed each second from the client to the server, and in this new configuration i think that there will be some performance penalties due to this.
How should i "attack" this situation ?
Thanks,
but as i understand java rmi is faster then webservices.
Why do you think this? Do you have a citation to bolster this claim?
Both RMI and webservices are using TCP/IP; both incur similar network latency. The former uses Java or CORBA serialization to send messages over the wire; the latter uses either HTTP (for REST) or XML over HTTP (for SOAP or RPC-XML).
The relative speed is far more dependent on what those services are doing and how you code them.
I would prefer a web service because simple and open win. You are restricted to RMI/CORBA clients if you use RMI.
Nice. You are running Spring and you already have all you need. Just throw in a few jars (spring webservices and related jars) and you should be good to go.
Please refer :
http://static.springsource.org/spring/docs/2.5.4/reference/ejb.html
http://static.springsource.org/spring/docs/2.5.4/reference/remoting.html