org.eclipse.sisu.space

Customizable scanning of bean implementations.

The SpaceModule should be given a ClassSpace representing the classes and resources to scan:

 Guice.createInjector( new SpaceModule( new URLClassSpace( classloader ) ) );

Reduce scanning time by using an index or provide your own ClassFinder approach:

 Guice.createInjector( new SpaceModule( new URLClassSpace( classloader ), BeanScanning.INDEX ) );

---

The default visitor strategy is to use QualifiedTypeVisitor with QualifiedTypeBinder to find types annotated with @Named or other @Qualifiers and bind them as follows:

Components

Any qualified components are bound using a special "wildcard" key that the BeanLocator uses to check type compatibility at lookup time:

(This avoids the need to walk the type hierarchy and register bindings for each and every super-type, turning the injector graph to spaghetti.)

 @Named("example") public class MyTypeImpl implements MyType {
   // ...
 }

If you use an empty @Named or a different @Qualifier annotation then Sisu will pick a canonical name based on the implementation type.

Sometimes you need explicit typed bindings for external integration; you can list the types in a @Typed annotation or leave it empty to use the declared interfaces:

 @Named @Typed public class MyTypeImpl implements MyType {
   // ...
 }

Default implementations can be indicated by using "default" as a binding name:

 @Named("default") public class MyTypeImpl implements MyType {
   // ...
 }

or by starting the implementation name with "Default":

 @Named public class DefaultMyType implements MyType {
   // ...
 }

Default components are bound without a qualifier and have a higher ranking than non-default components.

Providers

Any qualified providers are bound using the same binding heuristics as components:

 @Named public class MyProvider implements Provider<MyType> {
   public MyType get() {
     // ...
   }
 }

Use @Singleton to scope the provided binding(s) as a singleton:

 @Named @Singleton public class MyProvider implements Provider<MyType> {
   public MyType get() {
     // ...
   }
 }

Note: this is different to the normal Guice behaviour where singleton only applies to the provider itself.

Modules

Any qualified modules are are installed using the current binder:

 @Named public class MyModule extends AbstractModule {
   @Override protected void configure() {
     // ...
   }
 }

Mediators

Any qualified Mediators are registered with the BeanLocator:

 @Named public class MyMediator implements Mediator<Named, MyType, MyWatcher> {
   public void add( BeanEntry<Named, MyType> entry, MyWatcher watcher ) throws Exception {
     // ...
   }
 
   public void remove( BeanEntry<Named, MyType> entry, MyWatcher watcher ) throws Exception {
     // ...
   }
 }