Package org.apache.sling.api.adapter

Interface AdapterFactory

All Known Implementing Classes:
WorkItemAdapterFactory
@ConsumerType public interface AdapterFactory
The AdapterFactory interface defines the API for helpers which may be provided to enhance the adaptability of adaptable objects.

Implementations of this interface are registered as OSGi services and are used by the AdapterManager to adapt objects on demand. The AdapterFactory services are not really intended to be used by clients directly.

The AdapterManager implementations ensures that the getAdapter(Object, Class) method is only called for the combination of adaptable and adapter type which is allowed as per the service registration properties ADAPTABLE_CLASSES and ADAPTER_CLASSES.

If multiple implementations for the same combination of adapter and adaptable are registered, the implementation with the lowest service ranking wins (or with the highest service id, if the ranking is the same).

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    ADAPTABLE_CLASSES
    The service registration property listing the fully qualified names of classes which can be adapted by this adapter factory (value is "adaptables").
    static final String
    ADAPTER_CLASSES
    The service registration property listing the fully qualified names of classes to which this factory can adapt adaptables (value is "adapters").
    static final String
    SERVICE_NAME
    The service name to use when registering implementations of this interface as services.

  • Method Summary

    Modifier and Type
    Method
    Description
    <AdapterType>
    AdapterType
    getAdapter(@NotNull Object adaptable, @NotNull Class<AdapterType> type)
    Adapt the given object to the adaptable type.

  • Field Details

    • SERVICE_NAME

      static final String SERVICE_NAME
      The service name to use when registering implementations of this interface as services.
      See Also:

    • ADAPTABLE_CLASSES

      static final String ADAPTABLE_CLASSES
      The service registration property listing the fully qualified names of classes which can be adapted by this adapter factory (value is "adaptables"). The "adaptable" parameters of the getAdapter(Object, Class) method must be an instance of one of these classes for this factory to be able to adapt the object.
      See Also:

    • ADAPTER_CLASSES

      static final String ADAPTER_CLASSES
      The service registration property listing the fully qualified names of classes to which this factory can adapt adaptables (value is "adapters").
      See Also:

  • Method Details

    • getAdapter

      @Nullable <AdapterType> AdapterType getAdapter(@NotNull @NotNull Object adaptable, @NotNull @NotNull Class<AdapterType> type)
      Adapt the given object to the adaptable type. The adaptable object is guaranteed to be an instance of one of the classes listed in the ADAPTABLE_CLASSES services registration property. The type parameter is one of the classes listed in the ADAPTER_CLASSES service registration properties.

      This method may return null if the adaptable object cannot be adapted to the adapter (target) type for any reason. In this case, the implementation should log a message to the log facility noting the cause for not being able to adapt.

      Note that the adaptable object is not required to implement the Adaptable interface, though most of the time this method is called by means of calling the Adaptable.adaptTo(Class) method.

      Type Parameters:
      AdapterType - The generic type of the adapter (target) type.
      Parameters:
      adaptable - The object to adapt to the adapter type.
      type - The type to which the object is to be adapted.
      Returns:
      The adapted object or null if this factory instance cannot adapt the object.