Connect two GWT applications - Client/Server - java

What is the best way to connect two GWT applications, a web (Client) and a mobile Application (Server with GWT Mobile).
I tried to do that with RPC but it has not worked.
The database is in the server part.
Any idea ?
Thanks in advance

Well the easiest way if you ask me is to use REST instead of gwt rpc.
Please take a look at RestyGWT for your GWT-client application, on server - any JAX-RS implementation will do, We're using Glassfish Jersey on a tomcat - works like charm.

Related

Best practise to get database content from Wildfly

We're running a Wildfly Server with an Java EE application that uses Hibernate. Now we need to implement a Java SE client that get some data from the database that Wildfly is using. What's the best practise for doing that? Using something like RPC? Or JAX-RS Client? The database itself is not accessible within the client. Thanks for helping!
It very much depends on how your server app is working and whether you have access to it's source code and ability to change it in case it doesn't have any web service implemented inside.
If your server app already does have any endpoints, the best choice would be to use those.
In case it doesn't have any endpoints at all, the most usual solution would be create JAX-RS web service on server application and use it in your Java SE client application.

Restful Webservice Java, server side

I'm trying to develop a small server which would include one restful webservice.
I'd like to use JAX-RS for the webservice part, but every example I'm seeing is using a tomcat server, and I can't use any 'application' server (meaning I can create a server in my code, but can't run it from the outside).
Well anyway I was wondering if anyone had any sample to show, and any advice on which light library I could use to run such a simple server into my code (can't use any gpl /lgpl etc licence, so no jersey for example).
Thank you.
It's possible to embed Tomcat in your application, see here for an example: http://java.dzone.com/articles/embedded-tomcat-minimal
Another popular choice for an embedded servlet container is Jetty, they have a tutorial here.
Edit
The examples provided with Jersey can also be helpful, here's one for running using the Grizzly HTTP library: https://github.com/jersey/jersey/blob/master/examples/helloworld/src/main/java/org/glassfish/jersey/examples/helloworld/App.java
You can even use the HTTP server that's bundled with the JDK (probably not the way to go for a real application): https://github.com/jersey/jersey/blob/master/examples/helloworld-pure-jax-rs/src/main/java/org/glassfish/jersey/examples/helloworld/jaxrs/App.java
Have you checked out http://www.sparkjava.com/?
It's very light-weight and concise.
Building a server into code is nothing. See "Embedding Jetty", for one. There are plenty of other options with varying degrees of difficulty and capabilities, like the Simple Framework, Tomcat, Grizzly, Netty, and Vert.x, to name a few. Then, if you're not stuck with Java, the language, there's Ratpack for a lightweight REST server. Otherwise, running something like Jersey in an embedded server is quite simple. I do it every day in tests.

How do you access SQL database from GWT?

I've read some articles on the Internet that this is not possible. To communicate own SQL database that is located on other server from GWT application. Jetty doesn't allow it.
I found a way how to perform it but it's not very cosy. I have client and server part inside GWT. The server has to communicate with MySQL database on localhost. So I've written an ant script to build a war that I can launch on Apache Tomcat server. It works perfectly there but I'm not able to debug the code effectively.
Do you have some advices how to perform this task? I was thinking of writing the clienty only in GWT and find some waz how to communicate my own server written outside the GWT. I've found Apache Thrift for GWT but this edited library of thrift seem not to work properly.
Thank you very much for your answers:)
It is possible to communicate with a database from a GWT application. The client side has to call the methods of the server via GWT-RPC, which can communicate with any database.
Maybe Jetty does not support it (have not tested it personally) but you can develop your web application using Apache too. There you can access the database the same way as from any web application:
You will need the mysql-connector-java-5.1.20-bin.jar file (downloadable from: http://dev.mysql.com/downloads/connector/j/ ), and restart the server added to the $CATALINA_HOME/common/lib directory.
OR added to the WEB-INF/lib folder of your web application.
You can find tutorials online of how to develop an application using Tomcat instead of Jetty. For example: https://wiki.auckland.ac.nz/display/BeSTGRID/Deploying+GWT+to+Tomcat+in+Eclipse
Reshi, stop and think about how applications really work. Nobody provides web pages with javascript to read/write databases, that would be crazy and unsecure. Servers are always in themiddle of all communication in this case. You need to create services that run inside your server, one of these services will be a database layer.
Javascript cant create network connections and read/write binary data, thus it would be insane to attempt to get the gwt compiler to compile any jdbc drvier and more.
Jetty does NOT stop us from connecting to a database. All you have to do is to follow the MVP model way. Although MVP is better bet against all hurdles, at a minimal point, you would have to try not having SQL code on the client package.

Using Jersey without an application server

I am looking to use Jersey without the need of installing an application server such as Tomcat or Glassfish. Ideally I would like to create a lightweight program that listens on a port and allows connections. I believe you can do this with Grizzly + Jersey but I am not sure how easy this is, because from my understanding Grizzly is used to write new http servers from scratch?
Restlet looked good in this regard because it included an internal http server but the documentation provided is extremely meager.
You can use a light-weight servlet container like jetty. you can bundle and ship this with your application. Also building and shipping jetty with your application is very easy.
I've deployed an app recently that uses embedded Jetty in Spring to launch Jersey, so this is 100% possible. Jersey, in fact, has a SpringServlet for easy delegating to a Spring context based REST implementation. If you have additional questions down this route, let me know. It wasn't the most straight forward, but I can talk you through some of it with the appropriate links.

Java Web Service for .NET 2.0 Client on Linux (Fedora)

I'm tasked with creating a Java Web Service for a .NET 2.0 client to consume.
What would your suggestions for the implementation be?
The solution doesn't need to be very heavyweight (don't need a full Java EE container I believe) but what do you think is the best solution for this? I have thought about using Glassfish v2 with JAX-WS annotations (#WebService), and JAXB XML Bindings(e.g. #XmlElement), which I assume the .NET client would be able to consume?
Has anyone tried this scenario?
Would Glassfish be overkill though, since I'm merely using the Web Service as a mechanism for .NET on Windows to communicate to the Linux box, the underlying application is extremely small.
Any suggestions are more than welcome :)
Thanks,
James
P.S. Other notes - would you use Axis/CXF instead of Glassfish? Would you use a servlet container such as Tomcat? etc.
I have used Axis2 and it works.
I had the same problem of making Data Exposing API (Web Service in my case) in Java.
I made the web service using Axis2 and Spring (to access database) and the WSDL created via Axis2 was easily consumed via ASP.NET Application via its Add Web Service Dialog Box and the corresponding Proxy Classes were created easily.

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