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 simple injection of configuration properties through the DeltaSpike configuration mechanism.

A default implementation is provided in DeltaSpike for basic String injection points:

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

It's possible to use config properties in a type-safe manner, which requires a custom producer:

   @Target({FIELD, METHOD})
   @Retention(RUNTIME)
   @ConfigProperty(name = "locationId")
   @Qualifier
   public @interface Location {
   }
 

   @Location
   private String locationId;
 

   @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;
     }
   }
 

Producers can be implemented to support other types of injection points:

   @Inject
   @Location
   private LocationId locationId;
 

   @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());
     }
   }
 

For custom producer implementations, BaseConfigPropertyProducer can be used as the base class.

See Also:

ConfigResolver, BaseConfigPropertyProducer

Field Summary

Fields

Modifier and Type	Fields and Description
static String	NULL This constant is a workaround for the java restriction that Annotation values cannot be set to null.

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.

Field Detail

NULL

public static final String NULL

This constant is a workaround for the java restriction that Annotation values cannot be set to null. Do not use this String in your configuration.

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"