Package org.eclipse.microprofile.config.inject

Annotation Interface ConfigProperty

@Qualifier @Retention(RUNTIME) @Target({METHOD,FIELD,PARAMETER,TYPE}) @Requirement(namespace="osgi.cdi.extension",name="org.eclipse.microprofile.config",effective="active") @Requirement(namespace="osgi.cdi.extension",name="org.eclipse.microprofile.config",resolution=OPTIONAL) 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 DeploymentException 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 is not defined, 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.

  • Optional Element Summary

    Optional Elements
    Modifier and Type
    Optional Element
    Description
    String
    defaultValue
    The default value if the configured property does not exist.
    String
    name
    The key of the config property used to look up the configuration value.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    UNCONFIGURED_VALUE
     

  • Field Details

  • Element Details

    • name

      String name
      The key of the config property used to look up the configuration value.

      If it is not specified, it will be derived automatically as <class_name>.<injection_point_name>, where injection_point_name is the field name or parameter name, class_name is the fully qualified name of the class being injected to.

      If one of the class_name or injection_point_name cannot be determined, the value has to be provided.

      Returns:
      Name (key) of the config property to inject
      Default:
      ""

    • defaultValue

      String defaultValue
      The default value if the configured property does not exist. This value acts as a configure source with the lowest ordinal.

      If the target Type is not String, a proper Converter will get applied. Empty string as the default value will be ignored, which is same as not setting the default value. That means that any default value string should follow the formatting rules of the registered Converters. If a property has been emptied by a config source with a higher ordinal by setting an empty configuration value or by using a value causing the used converter returning null, the default value will not be used.

      Returns:
      the default value as a string
      Default:
      "org.eclipse.microprofile.config.configproperty.unconfigureddvalue"