org.apache.deltaspike.core.spi.config

Class BaseConfigPropertyProducer

java.lang.Object

org.apache.deltaspike.core.spi.config.BaseConfigPropertyProducer

public abstract class BaseConfigPropertyProducer
extends Object

This contains the fundamental parts for implementing own ConfigProperty producers.

Providing own Converters and Type injection

DeltaSpikes own configuration system natively supports only Strings. If you'd like to apply own Converters or extract other types from those Strings, you can simply do this by providing an own Qualifier and a simple CDI producer method for it.

First we write a simple Qualifier:

 @Target({ PARAMETER, FIELD, METHOD, CONSTRUCTOR, ANNOTATION_TYPE })
 @Retention(RUNTIME)
 @ConfigProperty(named="unused") // the name
 @Qualifier
 public @interface NumberConfig
 {
     @Nonbinding
     boolean name(); // the name of the configuration-key to lookup the value

     @Nonbinding
     String defaultValue() default ConfigProperty.NULL;

     @Nonbinding
     boolean pattern(); // the pattern for NumberFormatter
 }
 

The producer method implementation is pretty easy as well:

 @ApplicationScoped
 public class NumberConfigProducer extends BaseConfigPropertyProducer
 {
     @Produces
     @Dependent
     @NumberConfig
     public Float produceNumberConfig(InjectionPoint injectionPoint)
     {
         // resolve the annotation
         NumberConfig metaData = getAnnotation(injectionPoint, NumberConfig.class);

         // get the configured value from the underlying configuration system
         String configuredValue = getPropertyValue(metaData.name(), metaData.defaultValue());
         if (configuredValue == null)
         {
             return null;
         }

         // format according to the given pattern
         DecimalFormat df = new DecimalFormat(metaData.pattern(), new DecimalFormatSymbols(Locale.US));
         return df.parse(configuredValue).floatValue();
     }
 }
 

Constructor Summary

Constructors

Constructor and Description
BaseConfigPropertyProducer()

Method Summary

Methods

Modifier and Type	Method and Description
<T> ConfigResolver.TypedResolver<T>	asResolver(String key, String stringDefault, Type ipCls, Class<? extends ConfigResolver.Converter> converterType, String parameterizedBy, boolean projectStageAware, boolean evaluate)
protected <T extends Annotation> T	getAnnotation(javax.enterprise.inject.spi.InjectionPoint injectionPoint, Class<T> targetType)
protected <T> T	getPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint, Class<T> ipCls)
protected String	getPropertyValue(String propertyName, String defaultValue)
protected String	getStringPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint) Inspects the given InjectionPoint and search for a ConfigProperty annotation or an Annotation with a ConfigProperty meta-Annotation.
protected <T> T	getUntypedPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint, Type ipCls)
<T> T	readEntry(String key, String stringDefault, Type ipCls, Class<? extends ConfigResolver.Converter> converterType, String parameterizedBy, boolean projectStageAware, boolean evaluate)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

BaseConfigPropertyProducer

public BaseConfigPropertyProducer()

Method Detail

getStringPropertyValue

protected String getStringPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint)

Inspects the given InjectionPoint and search for a ConfigProperty annotation or an Annotation with a ConfigProperty meta-Annotation. The name and defaultValue information will be used to resolve the configured value.

Parameters:

injectionPoint - current injection point

Returns:

the configured value for the given InjectionPoint

getPropertyValue

protected <T> T getPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint,
                     Class<T> ipCls)

getUntypedPropertyValue

protected <T> T getUntypedPropertyValue(javax.enterprise.inject.spi.InjectionPoint injectionPoint,
                            Type ipCls)

getPropertyValue

protected String getPropertyValue(String propertyName,
                      String defaultValue)

Parameters:

propertyName - the name of the property key

defaultValue - the default value to return if no configured property is found or ConfigProperty.NULL if no default value should be returned.

Returns:

the configured value or the defaultValue according to the NULL logic.

getAnnotation

protected <T extends Annotation> T getAnnotation(javax.enterprise.inject.spi.InjectionPoint injectionPoint,
                                     Class<T> targetType)

Type Parameters:

T - type

Parameters:

injectionPoint - current injection point

targetType - target type

Returns:

annotation instance extracted from the injection point which matches the given type

readEntry

public <T> T readEntry(String key,
              String stringDefault,
              Type ipCls,
              Class<? extends ConfigResolver.Converter> converterType,
              String parameterizedBy,
              boolean projectStageAware,
              boolean evaluate)

asResolver

public <T> ConfigResolver.TypedResolver<T> asResolver(String key,
                                             String stringDefault,
                                             Type ipCls,
                                             Class<? extends ConfigResolver.Converter> converterType,
                                             String parameterizedBy,
                                             boolean projectStageAware,
                                             boolean evaluate)