org.apache.deltaspike.core.api.config

Annotation Type ConfigProperty

@Target(value={PARAMETER,FIELD,METHOD,CONSTRUCTOR,ANNOTATION_TYPE})
@Retention(value=RUNTIME)
@Documented
@Qualifier
public @interface ConfigProperty

This Qualifier allows to use the DeltaSpike configuration mechanism via simple injection.

Example 1:

   @Inject @ConfigProperty(name="locationId")
   private String locationId;
 

Example 2 (the type-safe alternative):

   @Target({ FIELD, METHOD })
   @Retention(RUNTIME)
   @ConfigProperty(name = "locationId")
   // alternative to null check in the producer:
   // @ConfigProperty(name = "locationId", defaultValue = "LOCATION_X")
   @Qualifier
   public @interface Location
   {
   }
 

Depending on the producer it's possible to use a String or a custom type like an enum at the injection point.

With a String:

   @Location
   private String locationId;
 

With a custom type:

   @Inject
   @Location
   private LocationId locationId;
 

In any case a custom producer is needed. BaseConfigPropertyProducer can be used as an base for custom producers. Producer for the configured String:

   @ApplicationScoped
   public class CustomConfigPropertyProducer extends BaseConfigPropertyProducer
   {
     @Produces
     @Dependent
     @Location
     public String produceLocationId(InjectionPoint injectionPoint)
     {
       String configuredValue = getStringPropertyValue(injectionPoint);
       if (configuredValue == null)
       {
         return null;
       }
       return configuredValue;
     }
   }
 

Producer for a custom type:

   @ApplicationScoped
   public class CustomConfigPropertyProducer extends BaseConfigPropertyProducer
   {
     @Produces
     @Dependent
     @Location
     public LocationId produceLocationId(InjectionPoint injectionPoint)
     {
       String configuredValue = getStringPropertyValue(injectionPoint);
       if (configuredValue == null)
       {
         return null;
       }
       return LocationId.valueOf(configuredValue.trim().toUpperCase());
     }
   }
 

See Also:

ConfigResolver, BaseConfigPropertyProducer

Required Element Summary

Required Elements

Modifier and Type	Required Element and Description
String	name Name/key of the property

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
String	defaultValue Optional default value.

Element Detail

name

public abstract String name

Name/key of the property

Returns:

name of the property

defaultValue

public abstract String defaultValue

Optional default value.

Returns:

the default value which should be used if no config value could be found

Default:

"org.apache.deltaspike.NullValueMarker"