Package org.jvnet.hk2.config

Annotation Type DuckTyped

@Retention(RUNTIME)
@Target(METHOD)
@Documented
public @interface DuckTyped

Indicates that this method on ConfigBeanProxy is a duck-typed method that are implemented by the static method on the nested static Duck class.

Usage

Often it's convenient if one can define some convenience methods on the config bean proxy. This mechanism allows you to do that by putting this annotation on a convenience method, then write the nested static Duck class and places the actual implementation there.

 interface MyConfigBean extends ConfigBeanProxy {
    @Element
    List<Property> getProperties();

    <DuckTyped
    String getPropertyValue(String name);

    class Duck {
        public static String getPropertyValue(MyConfigBean me, String name) {
            for( Property p : me.getProperties() )
                if(p.getName().equals(name))
                    return p.getValue();
            return null;
        }
    }
 }
 

The invocation of the getPropertyValue above will cause HK2 to in turn invoke the corresponding static method on Duck, where the first argument will be the original this value.

Author:

Kohsuke Kawaguchi

See Also:

ConfigBeanProxy