GAE: Is it possible to build web service with endpoint within firewall? - java

I'm planning to build a two-tier application, with a back-end (java, possibly spring MVC) which delivers JSON up to a front-end (PHP, Drupal7). I only want the front-end application exposed to the outside world and in a traditional environment I would probably stick the back-end on some ports inside the firewall (assuming both parts run within the FW).
Is this possible to do in the Google App Engine environment?

It's not possible to run GAE inside your firewall. It runs on Google's servers.

You can do basic things like blocking IPs but its not really necessary. Since your 'front end' has the php backend you can call from there your appengine with a secret parameter (as in "myapp.appspot.com?key=sE34sdJSjUy" ) Its very simple security and since no one can see that url (in your php backend), its as good as any other authentication method.

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Launching JAR file from network drive using remote origin

I have an application implemented in JavaFX and it will be migrated to the web platform, but it will take some time for that.
Meanwhile, I am struggling with some problems regarding its uses. Some users need to launch the jar from a network drive because their machines do not have access to the the database. Only the drive where the jar is located has access to the database.
My doubt is whether running the jar from the allowed network drive will solve this problem. In addition, can JNLP be a solution for this ?
I'd appreciate any help about this.
Some users need to launch the jar from a network drive because their machines do not have access to the the database. Only the drive where the jar is located has access to the database. My doubt is whether running the jar from the allowed network drive will solve this problem.
It won't work directly.
JavaFX is a client technology, it runs on a client PC. If the client PC does not have direct access to a database, then neither does a JavaFX application running on that client PC.
In addition, can JNLP be a solution for this ?
No, not for direct access to the database from the client if this isn't permitted in your network architecture, you would need a middle tier in addition to the JNLP based client to accomplish this.
Discussion of some solutions to this problem
Typically, the architecture of what you are describing would be built as a multi-tier app.
A client tier, which is the the JavaFX application or HTML javascript application running on a client machine.
An application server tier which handles server logic.
A database tier which hosts the DBMS.
There is a reasonable high level overview of such an architecture here.
Often, nowadays, the application server will serve REST APIs of JSON data, which a HTML based JavaScript web application can easily consume. Such APIs are also easily consumed using JavaFX applications which embed a REST client. An application server services the REST APIs and communicates with a database over JPA or JDBC as appropriate. However, than are many alternate technologies for client/server communication, and you can choose whatever you feel is a good fit for your application, development style and organization.
Spring product specific discussion
As you state your preference to use Spring, consider a JavaFX SpringBoot application.
Spring also includes a technology called spring remoting for facilitating client/server access. Spring remoting provides for multiple communication technologies. I'd advise sticking to the straight HTTP REST based technologies rather than other techniques such as RMI or AMQP as a HTTP REST based back-end can also serve as the backend for a standard HTML/JavaScript webapp which you also mention may be an eventual target client for your application.
If using Spring on client and server, checkout Spring's AsyncRestTemplate, and invoke JavaFX's Platform.runLater API inside the success and failure callbacks of the rest template. Or, use a Spring RestTemplate and control calls to the server via JavaFX concurrency mechanisms. Not sure which would be best for you, possibly the standard RestTemplate wrapped in a JavaFX Task.
Doing this in the correct manner will allow your application UI to remain responsive while it performs network activity (not block the UI thread) and also ensure that you don't violate JavaFX thread rules (don't access controls or modify data bound to JavaFX scene controls off of the JavaFX application thread).

Java Desktop Application Client-Server all in one

I'm thinking about what might be the best solution to create a standalone client-server application in java with these features:
Server: it must provide APIs (probably rest?)
Client: javafx webview with angularjs to make requests to webserver.
Loader; it starts the server and the client;
The user can then manage the application directly from the webview or from the browser (to the server port)
This would also be able to create in the future a "cloud" version of the application, the client instead to query the localhost will perform to a remote server.
A solution of this type is correct?
What might be useful tools for its realization and how could it be structured?
I would like in particular a solution which does not require the use of a large Java Application Server, but something more simple that it can be included as a library.
I thought same architecture which you think because it's easy. localhost binding, angularjs, bootstrap in java Webview. one of solutions is Spring MVC Rest API with embedded tomcat. it may be not lightweight.

How to create objects in server application and be able to call them from client application

I am learning to program Java. My objective is to create client server application based on Java and MySQL.
That would have following.
Server Application where all admin controls would be available to configure.
server application will be the only to have access rights to MySQL.
Server will have all functions and objects that clients will require and call and get that functionality. (Reason for that is "I don't want to share MySQL credentials to client apps or rather i don't want MySQL credentials to be transmitted on the network to clients"). As it would increase maintenance tough and it could be a security loop hole.
An analogy of functionality could be: client calls to server telling to add an Order such addOrder(order_id, payment,..,...,..) and so on.
What are the method in practice for such kind of application these days? A example code/or material to get in right direction would suffice
These days the universal way to expose a service remotely is via a web service. This solution was preferred by the industry over time due to its simplicity and ease of integration to the point that binary based protocols like CORBA are now seldom used.
Take the example of Android applications, they are native application mostly using REST web services.
A REST web service can be easilly integrated in the same way with a desktop application, a mobile application or a web application, even if the clients are written in different native platforms and languages.
As sample code, have a look at tutorials on the Spring stack. For the server see this tutorial for building an hello word REST web service. For the client, consider the REST template.
For security, see this Spring security hello world example. Using the Spring stack in Java will likelly give you the largest number of tutorials and online support.
This sounds like a good place to use RMI, which Java has built in support for. RMI will allow your client to call server-side methods on a local object that corresponds to the server, where all messages/commands get transparently sent to the actual server, where you have your DB access stuff and logic.

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

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