@Retention(value=RUNTIME)
 @Target(value={METHOD,FIELD,PARAMETER,TYPE})
public @interface ConfigProperty

Binds the injection point with a configured value. Can be used to annotate injection points of type TYPE, Optional<TYPE> or javax.inject.Provider<TYPE>, where TYPE can be String and all types which have appropriate converters.

Injected values are the same values that would be retrieved from an injected Config instance or from the instance retrieved from ConfigProvider.getConfig()

Examples

Injecting Native Values

The first sample injects the configured value of the my.long.property property. The injected value does not change even if the underline property value changes in the Config.

Injecting a native value is recommended for a mandatory property and its value does not change at runtime or used by a bean with RequestScoped.

A further recommendation is to use the built in META-INF/microprofile-config.properties file mechanism to provide default values inside an Application. If no configured value exists for this property, a DeplymentException will be thrown during startup.

 @Inject
 @ConfigProperty(name="my.long.property")
 private Long injectedLongValue;
 

Injecting Optional Values

Contrary to natively injecting, if the property is not specified, this will not lead to a DeploymentException. The following code injects a Long value to the my.optional.long.property. If the property does not exist, the value 123 will be assigned. to injectedLongValue.

 @Inject
 @ConfigProperty(name="my.optional.long.property", defaultValue="123")
 private Long injectedLongValue;
 

The following code injects an Optional value of my.optional.int.property.

 @Inject
 @ConfigProperty(name = "my.optional.int.property")
 private Optional<Integer> intConfigValue;
 

Injecting Dynamic Values

The next sample injects a Provider for the value of my.long.property property to resolve the property dynamically. Each invocation to Provider#get() will resolve the latest value from underlying Config again. The existence of configured values will get checked during startup. Instances of Provider<T> are guaranteed to be Serializable.

 @Inject
 @ConfigProperty(name = "my.long.property" defaultValue="123")
 private Provider<Long> longConfigValue;
 

If ConfigProperty is used with a type where no Converter exists, a deployment error will be thrown.