DynamicPluginLoader Plugin loader that supports installed plugins at runtime  
PluginLoader Handles loading and unloading plugin artifacts from a location  


BundledPluginLoader Plugin loader that can find plugins via a single URL, and treats all plugins loaded from the directory as bundled plugins, meaning they can can be upgraded, but not deleted. 
ClassPathPluginLoader Loads plugins from the classpath  
DirectoryPluginLoader A plugin loader to load plugins from a directory on disk. 
DirectoryScanner Scans the filesystem for changed or added plugin files and stores a map of the currently known ones. 
FileListScanner A scanner that simply scans a given set of input files. 
ScanningPluginLoader Plugin loader that delegates the detection of plugins to a Scanner instance. 
SinglePluginLoader Loads a single plugin from the descriptor provided, which can either be an InputStream or a resource on the classpath.