#JAVA REFLECTION ANDROID APK#
#JAVA REFLECTION ANDROID CODE#

Get the current class loader and pass it as parent when creating DexClassLoaderĭexClassLoader dexLoader = new DexClassLoader(fullPathToApk,Ĭlass loadedClass = Class.forName(fullClassName, true, loader) Public Class loadClassDynamically(String fullClassName, String fullPathToApk)įile dexOutputDir = androidContext.getDir(“dex”, Context.MODE_PRIVATE)

#JAVA REFLECTION ANDROID APK#

fullPathToApk is the full path to the apk or jar containing x with that class definition fullClassName is the fully qualified name of the class you want to load e.g. This way, your loader will first ask the parent for any class definition it has to resolve. The Java class loaders are hierarchical, so to make sure that you only have one PluginGame class at runtime, you must pass in the host’s class loader as the parent to your class loader. You will get this exception if the PluginGame class that you loaded is different from the PluginGame class that the host application knows about. Problem #1: ClassCastException when casting the dynamically created object to your base class However, if you don’t load the class properly, you’ll run into a great deal of unexpected trouble. View libgdxView = initializeForView(game, config) In our case, we can pass the object into LibGDX:

#JAVA REFLECTION ANDROID CODE#

Once this is done, you can forget in the rest of your code that you loaded the class dynamically, and treat it just like as a ‘regular’ object that was created using ‘new’. Object result = loadedClass.getConstructor().newInstance() Our end goal is to be able to write something like this:Ĭlass loadedClass = loadClassDynamically(fullClassName, fullPath) It could be downloaded from your server at runtime or stored on the device’s SD card, depending on your particular scenario. This is the actual game that will be loaded dynamically. The sdk also contains any shared libraries and interfaces that are used between the host application and the game implementations. During development time Sdk.jar is linked to both the host application project and to any plugin game implementation project. At runtime it is provided by the host application.Įxtends the base class PluginGame. In our case this base class implements the LibGDX ApplicationListenerinterface. It casts them to a specific base class PluginGame, and executes their logic.ĭefines the base class PluginGame. There are three major components in play: Note: In what follows, we will use the base class approach, but it works just as well with interfaces. This article describes all the tricks involved in using pre-defined base classes (the second option above) to achieve this. Unfortunately, this is exactly what we needed to do: to load LibGDX games dynamically and run them on our devices. It is therefore not usable if you need to integrate your class with a third-party framework. Reflection is fairly easy to get working, but is slow and more importantly you have to keep using reflection throughout your code.

Using a pre-defined interface or base class.

There are two ways of using dynamically loaded classes in your code:

Java reflection android