Tag Archives: extension

HTTP Request and Extensions integration

In this new recipe we’re going to take a look at how we can integrate regular HTTP calls with the SmartFoxServer runtime and specifically how to communicate with Extension code via HTTP GET/POST requests.

Common applications of the HTTP/Extension interoperability are debugging interfaces and administration UIs. With this approach developers can easily build a simple web interface that reports that game state, monitors data structures, users etc… allowing to quickly debug problems while testing, triggering events and so on.

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Using the trace(…) command from anywhere in your Extension code

The trace(…) method is a useful little tool to log any information in the log files for debugging your Extension code.

It is available in the main Extension class and in every Request or Event handler. However, often times, developers need to log messages from other places in their code such as data classes, or any other object that doesn’t extend the Request/Event base classes.

How can we call trace(…) from somewhere else? Continue reading

The singleton solution

One of the questions that often gets asked in our support forums is something along the lines of “How do I create a singleton class where to store data that is global among all Extensions?”


This is a relatively complex subject in SmartFoxServer because each Extension is loaded in a separate Class Loader, thus making it more difficult to create a singleton that can be shared.

If you’re not entirely familiar with how Extension loading works you can consult this article for a quick overview. Part of these rules are essentially inherited from the Java Virtual Machine (JVM) architecture and, even if they might seem a bit convoluted, they help with reloading new code at runtime without stopping or restarting the server.

There is however a simple deployment trick that can be employed. Using the extensions/__lib__/ folder we can deploy a jar file with one or multiple classes that will be accessible from any Extension, even throughout multiple reloads.

In other words this will not change the way in which you deploy your Extension in SmartFoxServer 2X, however you will need to export the Singleton class(es) to a separate jar file that will be deployed to –> extensions/__lib__/

From a coding point of view nothing changes, which means that you don’t need to create a different project for your Singleton(s). You can keep them with your main Extension project and just deploy them differently, as described. Most Java IDEs will allow you to export a number of selected classes to a specific jar file, which can then be deployed as we have discussed.