I've been asked by a client to develop a server heavily based on web services and web interfaces (HTML + Ajax GUIs). Now before I start googling, I'd like to hear from you all, what do you recommend for such a task. My goals:
Work with Spring + Hibernate (This is a basic requirement). I know there is Spring-WS, but it seems a little bit complicate. More it doesn't seem to integrate with Eclipse or Netbeans web service generation functions.
Be very very simple, to the level that every newbie can get into that easily and even seasoned developers, that are not so sparkling with new technologies, can work with it.
Ideally I'd like it to be easily assisted by IDEs like Netbeans or Eclipse, or Both!
I'd like if it is possible to have the same application serve J2EE webpages and the services
REST or NOT?
I don't want to implement nothing by myself, but I want to rely on existing solutions. I mean, I've been thinking of using JSON-RPC, but I've seen around that it is poorly supported on many platforms, plus I'd have to write certain parts by myself. I'd like proven technologies that work.
And eventually I'd like it to make coffee for everybody... no okay I'm kidding about this :)
check apache CXF. it is pretty simple and supports spring
http://cxf.apache.org/
Regarding REST it depends on the type of service you are trying to implement.
If the information you are returning would fit well in a tree structure then a REST service will map it very well and clients can get the granularity they need.
If you can't really 'drill down' into your data then maybe REST does not fit.
Related
First am not sure if this question fits here well. However couldn't think of a better place to get help. I've been tasked to list the Pros and Cons of each of these {JAX-RS, Playframework scala, MS Web Api}. I've done some research but couldn't conclude as I've not used all three to great extent. Have used playframework to create simple REST app. Have read the Web Api tutorials but have not implemented anything. Did research on JAX-RS but haven't implemented anything either. Also most of our developers are familiar with C# and introductory Java. I am more inclined towards playframework due to Scala,Akka,no server restart and scalability etc but not clear about the cons. One thing am sure is JAX-RS is standard Java EE and Web Api is standard MS stuff. Below are some of the app requirements:
Purely REST backend.
Proper authentication and authorization.
Online secure payment {Paypal etc}
Single front-end for both mobile and desktop
{angular/backbone/knockout..}
Allow users to subscribe as companies or part of companies.
Be able to connect to different databases without App restart.
Code maintenance and readability. Other members should be able to pickup without hassle.
Scalability
This is a partial answer because I worked only with playframwork 2.0 and JAX-RS.
Playframework is a MVC framework, you can use it to create some REST services but it's not focused on this kind of applications, so at least in version 2.0 it wasn't easy to add complex behavior like interceptors, etc. and you should manage authentication by yourself, I don't know if this has been improved in most recent versions of play framework.
JAX-RS is a specification to create REST services, there are several implementations like
Jersey, RESTeasy, Restlet between others. So JAX-RS implementations are built specifically to provide REST services in java. Most implementations have support to several authentications mechanism like OAuth, etc.
In my experience, JAX-RS is better to provide RESTful web services, and the code generated is in general more maintainable than the code generated in playframework, also playframework has a lot of things that maybe you don't need to use, but it will be loaded in memory when you start the server anyway. Akka it's a cool technology, but you can use it if you want it in any JAX-RS implementation.
If you want to build REST services using Scala, you could try Scalatra http://www.scalatra.org/
If you prefer java, take a look at http://dropwizard.io/, it's an embedded server that has Jersey (An implementation of JAX-RS) and a lot of cool things to provide RESTful web services, like metrics, etc, also it's easy to learn. If your team doesn't have an advanced java knowledge, this is a good option.
Playframework is great if you want an easy to learn MVC, specially for non java programmers but definitively it's not the right tool to build RESTful webservices based applications in my experience.
As stated in the question, I am looking for a Java-based (hopefully that does not require a full application server) event-based web applications development framework.
I have tried Vaadin, it was driving me insane. ZK Framework seems interesting, but it is pretty complex and there are no good examples of complex MVVC applications I know of, even though MVVC is the "way to go" in this framework.
Preferably, the framework I am looking for would be as much as possible similar to Android API, in the sense that the API is really well designed and that one can build very complex applications with it (i.e. CRUD interface within a CRUD, within a CRUD, with everything working as expected).
Another thing which we need is that the framework can be used not just for building business application, but also that web frontend can be built on top of it (even if special controls/widgets are needed).
Any ideas?
You can try GWT. Google Web toolkit is powerful tool for creating rich web application using Java as development language and eclipse as IDE. GWT provide cross browser ability and boilerplate code, so it is easy to bring rich AJAX based widgets. GWT is nice when you really need rich behavior capabilities on your client (GMail-like application).
It works very well with CRUD operation.
If you want to avoid "server-side only" frameworks you may have also a look at Apache Wicket as an alternative to JSF
We currently have a 2-tier Java Swing application sitting on top of MS SQL Server 2005. All the business logic is in the database. The client is quite old (and not very friendly), and for reasons of performance and scalability, we've already started porting some services to a middle tier in Java.
However, we still have a number of short and long term goals:
Pick a technology stack for a new front-end
This isn't easy - I can see everything from a web app at one end of the continuum to a traditional desktop app at the other being viable choices. The current front-end isn't really complex (mostly form-based), so I can see web/AJAX fitting, but it's an area where we don't know what we don't know.
Stacks on my list are:
Eclipse RCP, Netbeans RCP
Flex/Flash, Silverlight, JavaFX
Pure Javascript frontends (Sprout Core, Javascript MVC, ...)
Java-based Web frameworks (Wicket, JSF, ...)
Find a way of making the current application perform acceptably in a remote situation
We have some clients who resale our app to smaller clients and need to be able to remotely deploy it. Due to the 2-tier nature of the current architecture this leads to terrible performance (for example, calling a stored procedure that returns 18 result sets). We've used a Citrix solution in the past, but no-one likes that approach. Tunneling JDBC through port 80 also sounds like a bad idea. I was starting to wonder if there's anything that could use a X-Windows like approach to remote just the GUI part.
To simplify development and leverage your experience in Swing consider using Vaadin for your frontend. It is a Java framework for building modern web applications that look great, and perform well. All the code is written in Java and looks very similar to Swing.
As far as overall application architecture I would advise multi-tier, service oriented architecture. The best way to do it is by using Spring framework with Hibernate for database access.
If you want to easily redeploy your application, for an update, security reasons, etc. and if you want your application to be it to be accessed remotely, you should really consider a web based front end.
Plus, this way, only one app, your web app, will handle connection to the database, so no JDBC tunneling or whatever.
Concerning the best framework, it depends on your team knowledge, the way your application will be used (more or less javascript), etc.
We've just gone through a very similar evaluation process as we're migrating a legacy application.
For us the biggest deciding factor in what front-end framework to use was the prior knowledge of the development team. We wanted something that everybody would be comfortable with immediately. We had a couple of the senior developers that have worked with X or Y, but the framework that everybody knew was Swing.
In the end we decided on the NetBeans platform using RESTful webservice to communicate with an EE server.
As a bonus you can get your NetBeans platform application to deploy as a Java WebStart application, which means you get the benefit of not having to worry about individual installations.
If the frontend is mostly form-based, I would stay away from Flex. Flex is great for some applications (I'm using it for a canvas based application), but the form components of Flex has some usability issues. They just don't work like you expect from todays web. (like missing support for mousewheel, typing in dropdownlist only take first character into account etc.)
Assuming that you are going to force all your clients to install a new middle tier, I can't think of an argument against making it a Java web app. As already mentioned you have the benefit of controlling all access into your platform over HTTP, which allows easy resale, just with firewall configuration. There's no reason you can't make use of Javascript within a web front end, you may be interested in DWR, which allows you to interact directly with Java objects via Javascript. I've used this before to add some simple Ajax interaction to a Spring MVC webapp.
The reasons I like this approach, you're already migrating code into Java middle tier, so
Already imposing Java server hardware cost on clients, hosting app server / web server is comparable
Already have Java expertise, can be leveraged with DWR
Can use as much/little Javascript as appropriate (I've used DWR with IE6, Firefox 3, Chrome)
I think you're right to be wary of pushing too much functionality to the client, I'd go for as thin a client as possible. The only reason I'd look at the first two stack choices would be if you have some developer expertise in a particular area, and not Java webapp/Javascript.
I'd suggest to create a short list of candidate frameworks and create a small test application with all of them. This way you will get a sense of good and bad aspects from all of them and also get a picture what the community activity and documentation is like for each project (there is a lot of variance on those).If you end up doing this I hope you'll include Vaadin in your short list, I think it would fit you very well. If you have any questions just come over to our forums and we'll help you to get started.
I'm currently working on implementing the public API of our web application. The application is written in Java.
This is a financial application deployed on Tomcat. My users can manage their sales, customers, purchases, inventory, etc. It's a pretty huge application. The font-end is written in Java/GWT. The backend is written in Java s well. We use the GWT-RPC mechanism between.
What we want is to provide a way to access the financial data (read + write) via a public API. This way, developers will be able to better integrate their application (like a payroll application).
We don't use any framework. No Spring, grails, whatever. Also, no Hibernate, JPA, etc. It's a pretty old app, with lot of proprietary code for the ORM, XML-> javabean. authentication, etc. Cannot change all of that as the application is already in production and it just works that way.
The API infrastructure will be on a different sub-domain and on a different server.
The API should use Oauth to authenticate the users.
I looked into Grails, Play!Framework and Restlet to achieve my goals
Does anyone have some thought on them? Am I going in the wrong way with those frameworks? Is there another framework to look at?
Thank you all
I'd recommend following the example of Amazon and such and expose that API as web services, without regard for UI. Your have a further choice about SOAP versus REST. I think you'll find that REST will be simpler for your clients, because they only need to know about HTTP.
This doesn't mandate the use of any frameworks if you choose not to. The back end will work regardless of whether or not you use Spring, Hibernate, Grails, etc.
You'd have to rework the application you have to call the services if you wanted true reuse, but it might be worth it in the long run. Both your UI and clients would be using a common back end API that way.
I have some thoughts yes. Financial applications tend not to use OAuth. To be clear: nobody with vulnerable data uses OAuth. That includes privacy, medical and financial data.
What kinds of deployment environments do you expect to use this API. That might narrow it down, the standard answer if you have absolutely no idea who your client is, is still supposedly SOAP (since so many people know and accept the buzzword).
If you're going to expose read/write to a Java-based financial services application over the public internet, I would look at SOAP-based web services with JAX-WS as there is a pretty mature security spec in WSS and the API is relatively easy to use and may not require much in the way of changes to your existing app.
REST is perceived as easier in general but for this type of application you might find your target audience is more familiar with SOAP anyway. All depends who your target audience is and exactly what you're trying to achieve, but worth considering.
If you have a Java based web application (J2EE webapp - never mind which other underlying frameworks are being used), and you wanted to introduce a Flash based front-end, would you use Laszlo or would you rather expose a ReST-like XML interface and build and deploy a Flash application that uses that?
On one hand, Laszlo is quite amazing - doing for Flash what JSP does for HTML. It is easy to work with. It fits in very well with the rest of the web application (which is JSP based).
On the other hand it might be better to develop a complete Flash app decoupled from the server and use an XML-over-HTTP mechanism to bind the two. This would have the added advantage of being able to use the same XML interface for an AJAX front end if needed.
What would you do, and why?
I would create the contract-first services, deploy them separately, and then write the RIA client to access them.
Coming up with the schema first has the added benefit of completely decoupling the two during development. The RIA developer can create some synthetic XML streams to use for data while waiting for the services to come on-line.
I might have considered Laszlo in the past, but today, I'd stay within the Java stack and use JavaFX.
Laszlo is the product that never made it, there isn't a big enough ecosystem of developers around it.
I'd use Adobe Flex for the front end. The same benefits of using a markup language for doing flash, but it has a much larger developer base and open source projects to draw upon. For the data communication, use either REST or if you want to get clever, use BlazeDS.
OpenLaszlo is a complete RIA framework, so I'm pretty sure that you can 'compile' it to a completely standalone app that communicates with the server over HTTP. It's really very similar to Flex. The advantage Flex has is a much bigger community, a full-blown IDE, and more resources (Adobe), while OpenLaszlo is a little more innovative in that you can deploy to Flash or AJAX from one codebase.
I've actually spent some time working on a implementation similar to what you're suggesting. I had a complied Open Laszlo front end embedded in a web page with a Django (a python MVC library) REST interface on the backend and no Open Laszlo server. It works reasonably well, but there are a couple of things to watch out for. Open Laszlo only supports calls to GET and POST, so you won't be able to easily use the DELETE and PUT methods in your REST API. The other is the lack of community around Laszlo (as mentioned elsewhere). I can sometimes be frustratingly difficult to answer some basic questions when using Laszlo, particularly around the XML HTTP API and XML replication features in the framework. I personally never really looked at the Laszlo back end server seriously as I wanted an open API that could be consumed easily by other clients.
All this being said, the implementation does work and can be effective if you're willing to work around the limitations mentioned above. Plus Open Laszlo is free, which can be a really big plus if your working on a budget.