org.apache.felix.dm

Interface AdapterComponent

All Superinterfaces:

AbstractComponent, Component<AdapterComponent>

public interface AdapterComponent
extends Component<AdapterComponent>

Interface used to configure the various parameters needed when defining a Dependency Manager adapter component. Adapters, like AspectComponent, are used to "extend" existing services, and can publish different services based on the existing one. An example would be implementing a management interface for an existing service, etc ....

When you create an adapter component, it will be applied to any service that matches the implemented interface and filter. The adapter will be registered with the specified interface and existing properties from the original service plus any extra properties you supply here. If you declare the original service as a member it will be injected.

Usage Examples

Here is a sample showing a HelloServlet adapter component which creates a servlet each time a HelloService is registered in the osgi service registry with the "foo=bar" service property.

 
 public class Activator extends DependencyActivatorBase {
     &Override
     public void init(BundleContext context, DependencyManager dm) throws Exception {
         Component adapterComponent = createAdapterComponent()
             .setAdaptee(HelloService.class, "(foo=bar)")
             .setInterface(HttpServlet.class.getName(), null)
             .setImplementation(HelloServlet.class);
         dm.add(adapterComponent);
     }
 }
 
 public interface HelloService {
     String sayHello();
 }
 
 public class HelloServlet extends HttpServlet {
     volatile HelloService adatpee; // injected
     
     void doGet(HttpServletRequest req, HttpServletResponse resp) {
         ...
         resp.getWriter().println(adaptee.sayHello());
     }
 }
  

When you use callbacks to get injected with the adaptee service, the "add", "change", "remove" callbacks support the following method signatures:

 (Component comp, ServiceReference ref, Service service)
 (Component comp, ServiceReference ref, Object service)
 (Component comp, ServiceReference ref)
 (Component comp, Service service)
 (Component comp, Object service)
 (Component comp)
 (Component comp, Map properties, Service service)
 (ServiceReference ref, Service service)
 (ServiceReference ref, Object service)
 (ServiceReference ref)
 (Service service)
 (Service service, Map propeerties)
 (Map properties, Service, service)
 (Service service, Dictionary properties)
 (Dictionary properties, Service service)
 (Object service)
 

For "swap" callbacks, the following method signatures are supported:

 (Service old, Service replace)
 (Object old, Object replace)
 (ServiceReference old, Service old, ServiceReference replace, Service replace)
 (ServiceReference old, Object old, ServiceReference replace, Object replace)
 (Component comp, Service old, Service replace)
 (Component comp, Object old, Object replace)
 (Component comp, ServiceReference old, Service old, ServiceReference replace, Service replace)
 (Component comp, ServiceReference old, Object old, ServiceReference replace, Object replace)
 (ServiceReference old, ServiceReference replace)
 (Component comp, ServiceReference old, ServiceReference replace)
 

See Also:

DependencyManager.createAdapterComponent()

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.felix.dm.Component

Component.ServiceScope

Method Summary

Modifier and Type	Method and Description
AdapterComponent	setAdaptee(java.lang.Class<?> service, java.lang.String filter) Sets the service interface to apply the adapter to
AdapterComponent	setAdapteeCallbackInstance(java.lang.Object callbackInstance) Sets the instance to invoke the callbacks on (null by default, meaning the callbacks have to be invoked on the adapter itself)
AdapterComponent	setAdapteeCallbacks(java.lang.String add, java.lang.String change, java.lang.String remove, java.lang.String swap) Sets the callbacks to invoke when injecting the adaptee service into the adapter component.
AdapterComponent	setAdapteeField(java.lang.String autoConfig) Sets the name of the member to inject the service into
AdapterComponent	setPropagate(boolean propagate) Sets if the adaptee service properties should be propagated to the adapter service consumer (true by default)

Methods inherited from interface org.apache.felix.dm.Component

add, add, getServiceRegistration, remove, remove, setAutoConfig, setAutoConfig, setCallbacks, setCallbacks, setComposition, setComposition, setDebug, setFactory, setFactory, setImplementation, setInterface, setInterface, setInterface, setInterface, setScope, setServiceProperties

Methods inherited from interface org.apache.felix.dm.AbstractComponent

getComponentDeclaration, getDependencyManager, getInstance, getInstances, getServiceProperties

Method Detail

setAdaptee

AdapterComponent setAdaptee(java.lang.Class<?> service,
                            java.lang.String filter)

Sets the service interface to apply the adapter to

Parameters:

service - the service interface to apply the adapter to

filter - the filter condition to use with the service interface

Returns:

this adapter parameter instance

setAdapteeField

AdapterComponent setAdapteeField(java.lang.String autoConfig)

Sets the name of the member to inject the service into

Parameters:

autoConfig - the name of the member to inject the service into

Returns:

this adapter parameter instance

setAdapteeCallbacks

AdapterComponent setAdapteeCallbacks(java.lang.String add,
                                     java.lang.String change,
                                     java.lang.String remove,
                                     java.lang.String swap)

Sets the callbacks to invoke when injecting the adaptee service into the adapter component.

Parameters:

add - name of the callback method to invoke on add

change - name of the callback method to invoke on change

remove - name of the callback method to invoke on remove

swap - name of the callback method to invoke on swap

Returns:

this adapter parameter instance

setAdapteeCallbackInstance

AdapterComponent setAdapteeCallbackInstance(java.lang.Object callbackInstance)

Sets the instance to invoke the callbacks on (null by default, meaning the callbacks have to be invoked on the adapter itself)

Parameters:

callbackInstance - the instance to invoke the callbacks on (null by default, meaning the callbacks have to be invoked on the adapter itself)

Returns:

this adapter parameter instance

setPropagate

AdapterComponent setPropagate(boolean propagate)

Sets if the adaptee service properties should be propagated to the adapter service consumer (true by default)

Parameters:

propagate - true if the adaptee service properties should be propagated to the adapter service consumers. The provided adapter service properties take precedence over the propagated adaptee service properties. It means an adaptee service property won't override an adapter service property having the same name.

Returns:

this adapter parameter instance