Develop Reference

Developing app with web and Android client with Java

I'm going to start developing a new simple "X management" kind app, like contact management or events management. What I want to know is which tools would be the best to achieve it in the way I want.
My app needs to be a web app running on a server that has a mysql database to save and retrieve some simple information. This app must have a web client but I want it to be able to be extended to work with an Android app client.
Things I've thought:
I've worked on Java with facelets and JPA travels management app running on a GlassFish server on localhost with a JSF web view, so maybe my web client and the full app could be done with this.
I've worked with web services such as SOAP and REST with Jaxb and xml schemes to retrieve information parsing some webs into xml or json to show on a client .net app. So I've thought I can add to my app, like last topic we talked about, a REST web service layer to easily work as I want, or at least I think it would be easy. If I do this the Android app could share the same app core code but using the REST service.
My question is what could be the best way to do an app with 2 client side in different platforms that could share some code to be easy to extend it moreover to a desktop app. I've talked about these 2 options because I'm a students of computers at university and those are the tools I know, but I can easy learn more. I've also think about just a REST service and create a web and an Android client to work on same service or something like that.
This post is getting long, so here is the summary: What technologies and tools do you think are the best choice to create an java web app that needs to have web and Android client? Also what server, like tomcat, GlassFish or another, should I use? And what about persistence layer? JPA with mysql is the best I know to work with.
Thanks a lot.
P.D: I work with eclipse

From my point of view:
You can use java jersey and java spring both ( java spring as Dependency injection) for creating RESTful Web service. So, In server side you will create endpoint and you can access data from any platform through those endpoint.
Server can be anyone. It's up to you. I always try to use tomcat but tomcat is not a full JavaEE container it's only a servlet container. So if you want to use full JavaEE version then you should use Glassfish.
And yes JPA .It can be easily used in any environment supporting JPA including Java SE applications, Java EE application servers, Enterprise OSGi containers etc.
On the other hand, still choice is yours.

Spring webapp: sending notifications to java and android clients

I recently started developing my first web application with Spring and I'm stuck with a question I could not really find an answer to. What I have is a simple Spring MVC application running in tomcat which provides data in form of JSON, XML or binary via REST. This service is consumed by two clients I developed, a simple Java desktop application and an Android app. So far the clients only got information about new data by polling.
What I want now, is a way for the server to send notifications/messages to the clients when new data is available. For the Android client it would be good if the notifications could received anytime, not only when the app is currently open of course. I found lots of information for JavaScript client code but very little really useful, up-to date input about what the options for java and android clients are.
It would be really great if someone could give me some idea what would be the best way to achieve what I want (ideally something which integrates well with Spring on the server side), what protocols/libraries/frameworks to use, maybe even point me to some example or tutorial, how to implement this on server and client side.
Thanks in advance for any input.

For android or mobile devices, Google Cloud Messaging is the preferred way of sending messages to applications running on devices.
Example : spring gcm server side project and a sample tutorial.
For desktop apps, either poll regularly the server or run something in background like crontab or active-mq to check the messages and start the desktop app.

WebSockets are the best solution. check the implementation in java in the server side

Java Swing using Socket for enterprise application

After several months of searching & reading, now i need your help, taking in consideration the following:
- My Application Developed using Java Swing.
- MySQL has been used as database.
- JDBC has been used to make the communication between the application & database.
- The application will run on network environment with multiple client will connect to database.
- The application use Financial transactions, Posting, Billing ... etc.
** now i want to develop a server side that will work as middle-ware, this server side will do the following:
- Connecting to the database to retrieve data as client request.
- Business logic will be on the server side.
- Client will not know about the database.
- Queries Syntax will be on the server side.
- The Client will View,Save,Edit, Cancel ... etc, sending these actions to the server side & server will response.
--- I have read about JFC, J2EE, EJB ... etc, but i don't want to run my application from browser, it will be kept as desktop application only due to the complexity of the application.
--- So i will do it using Sockets.
Any ideas, or tutorials that i can follow?

I suggest using a web-based approach to writing the back-end (e.g. a web service, either SOAP or Rest), and then communicating between the swing app and the back-end app via HTTP / HTTPS.
This is how mobile apps are typically written, and your swing desktop app is no different from a mobile app in this respect.
As far as frameworks for the back end, both Spring MVC and Grails make this pretty easy. Do yourself a huge favor and stay away from EJB unless you really need.it and understand why.

When you have 1-2 hours left, it might be worth to look at the Scout framework.
Scout seems to be a pretty good fit to your application context. Scout applications consist of a Scout server that handles access to web services (currently including support for JAX-WS) and database access over JDBC. The Scout client communicates via HTTP(S) with the Scout server and is available in the form of desktop clients (either supporting Swing or SWT) and as web application (currently based on Eclipse RAP). The web client also supports different renderings to optimize the application to desktop browser or mobile devices with touch support.

Does iPad development work with interacting through Java code with Spring Framework using TomCat to host the web service on a server? How?

Here is the background of my situation:
I want to create an iPad application that interacts with a oracle SQL database. I have existing Java code from my Flex application that handles all the database requests, and modifications using the Spring Framework. The Flex Application ran as a web service through TomCat. Now I want to make that flex application into a mobile iPad version. I am having trouble figuring out what is the easiest way to use existing Java code and use it for the iPad because the iPad interacts using URL requests instead of direct with the Java.
My question is, can I use the existing Java code with the Spring framework to save time from coding all the back-end handling? Basically I want to access all the classes from my Java code by doing Requests from the iPad. Is this possible and will I need JSON or XML to interact between the iPad and the Java code?
Summary:
Can I use
iPad Objective-C <-----> Java (with spring framework) on TomCat Web Service to handle oracle SQL data handeling? If so, how and what technologies do I need? Will I need JSON or XML and how does that factor between the iPad and Java?
Thanks!

A good approach would be to design your app to communicate with RESTful services that return JSON. Once this is done your iPad app doesn't have to even know that the server code is written in Java.. it's just interacting over HTTP.
Here's a good tutorial on setting up your tomcat to host your RESTful services: http://www.vogella.com/articles/REST/article.html - I've used this for an app I'm developing. Spring isn't even necessary.
You could go XML, but JSON is just easier in my opinion. Here's a good blog outlining the good and bad of both sides. http://digitalbazaar.com/2010/11/22/json-vs-xml/

OK, I'm making the following presumptions.
Your flex application runs on a different machine from the Tomcat
server
Your flex application makes web service calls to the Tomcat server
So, the flex application doesn't know the underlying technology that provides the web services. It's just seeing/consuming the output
There's no reason why the iPad app can't do the same thing. There's no reason why it can't use the same web services that the Flex application uses. It could consume the same messages (Assuming it can handle the request/response format currently employed by the Flex application).
You can make changes if you like if you want to change the structure of the requests/responses between the clients. But the clients don't know (nor care) how the web services are implemented. They are just requesting and consuming info.

Java application vs web service vs web application

I am developing a multi-platform (Android, iPhone, Windows and Blacbberry) mobile application. The application needs to communicate with our server for several tasks, such as retrieving buddy lists etc. The server interacts with data that is stored in a MySQL database. I intend to code the server element in Java, however I am confused by all the different types. So far, I think I have narrowed it down to three options:
1) I code the application using Jetty to accept http posts. I post XML to the server, handle it, interact with the DB and post a XML response back. I would save the application as a jar and leave it running on my server.
2)I develop a Java web service. REST/JSON/SOAP?
3)I develop a Java web application.
Whilst there are many questions already out there asking what the differences is, I am struggling to find a clear explanation as to what is the best approach in which situation. I have previously used the first approach but am assuming the second approach is the better option, I'm just not sure what the advantage is.

your 1-3 options are all variants of a "Web application".
Jetty is a Java based http server/servlet container. If you want to communicate between client and server using http, you are using an http server (although not necessarily Jetty).
A Web Service is part of a web application that conforms to a standard around how clients communicate with the server, and how the server offers up information to the clients.
A web application is a Java application that makes it services available over http.
So if you want to have your clients communicate with a server, and store info in a db, you are using a web-application.

I would recommend going with option 2 as it is more lightweight and can be parsed directly in you're web application. XML got more overhead and must be translated, while you can just serialize objects directly to JSON from you're Java application and then parse them in javascript at frontend