diff --git a/README.md b/README.md index ff1870b..c60f487 100644 --- a/README.md +++ b/README.md @@ -1,16 +1,16 @@ Plugin Framework for Java (PF4J) ===================== -A plugin is a way for a third party to extend the functionality of an application. A plugin implements extensions points -declared by application or another plugins. Also a plugin can defines extension points. +A plugin is a way for a third party to extend the functionality of an application. A plugin implements extension points +declared by application or other plugins. Also a plugin can define extension points. Components ------------------- - **Plugin** is the base class for all plugins types. Each plugin is loaded into a separate class loader to avoid conflicts. - **PluginManager** is used for all aspects of plugins management (loading, starting, stopping). - **ExtensionPoint** is a point in the application where custom code can be invoked. It's a java interface marker. -Any java interface or abstract class can be marked as extension point (implements _ExtensionPoint_ interface). -- **Extension** is an implementation of extension point. It's a java annotation on a class. +Any java interface or abstract class can be marked as an extension point (implements _ExtensionPoint_ interface). +- **Extension** is an implementation of an extension point. It's a java annotation on a class. Artifacts ------------------- @@ -53,10 +53,10 @@ It's very simple to add pf4j in your application: } In above code, I created a **DefaultPluginManager** (it's the default implementation for -**PluginManager** interface) that load and start all active(resolved) plugins. +**PluginManager** interface) that loads and starts all active(resolved) plugins. The available plugins are loaded using a **PluginClassLoader**. -The **PluginClassLoader** contains only classes found in _classes_ and _lib_ folders of plugin and runtime classes and libraries of plugins that are required plugin. -The plugins are stored in a folder. You can specify the plugins folder in constructor of DefaultPluginManager. If the plugins folder is not specified +The **PluginClassLoader** contains only classes found in _classes_ and _lib_ folders of plugin and runtime classes and libraries of the required plugins. +The plugins are stored in a folder. You can specify the plugins folder in the constructor of DefaultPluginManager. If the plugins folder is not specified than the location is returned by `System.getProperty("pf4j.pluginsDir", "plugins")`. The structure of plugins folder is: @@ -68,9 +68,9 @@ A plugin folder has this structure: * `classes` folder * `lib` folder (optional - if the plugin used third party libraries) -The plugin manager discovers plugins metadata using a **PluginDescriptorFinder**. -**DefaultPluginDescriptorFinder** lookup plugins descriptors in MANIFEST.MF file. -In this case the `classes/META-INF/MANIFEST.MF` looks like: +The plugin manager searches plugins metadata using a **PluginDescriptorFinder**. +**DefaultPluginDescriptorFinder** lookups plugins descriptors in MANIFEST.MF file. +In this case the `classes/META-INF/MANIFEST.MF` file looks like: Manifest-Version: 1.0 Archiver-Version: Plexus Archiver @@ -95,7 +95,7 @@ You can define an extension point in your application using **ExtensionPoint** i } Another important internal component is **ExtensionFinder** that describes how plugin manager discovers extensions for extensions points. -**DefaultExtensionFinder** look up extensions using **Extension** annotation. +**DefaultExtensionFinder** looks up extensions using **Extension** annotation. public class WelcomePlugin extends Plugin { @@ -116,7 +116,7 @@ Another important internal component is **ExtensionFinder** that describes how p In above code I supply an extension for the `Greeting` extension point. -You can retrieves all extensions for an extension point with: +You can retrieve all extensions for an extension point with: List> greetings = pluginManager.getExtensions(Greeting.class); for (ExtensionWrapper greeting : greetings) { @@ -131,7 +131,7 @@ Demo I have a tiny demo application. The demo application is in demo folder. In demo/api folder I declared an extension point (_Greeting_). -In demo/plugin* I implemented two plugins: plugin1, plugin2 (each plugin add an extension for _Greeting_). +In demo/plugin* I implemented two plugins: plugin1, plugin2 (each plugin adds an extension for _Greeting_). To run the demo application use: