org.nakedobjects.applib.annotation.Encodeable Maven / Gradle / Ivy
package org.nakedobjects.applib.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Inherited;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import org.nakedobjects.applib.adapters.EncoderDecoder;
/**
* Indicates that the class can be encoded or decoded either by delegating to an {@link EncoderDecoder} or
* through some externally-configured mechanism.
*
* @see Defaulted
* @see Parseable
* @see Value
*/
@Inherited
@Target( { ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
public @interface Encodeable {
/**
* The fully qualified name of a class that implements the {@link EncoderDecoder} interface.
*
*
* This is optional because some implementations may pick up encodeability via a configuration file, or
* via the equivalent {@link #encoderDecoderClass()}.
*
*
* It is common for value classes to act as their own encoder/decoders. Note that the framework requires
* that the nominated class provides a public no-arg constructor on the class. It instantiates
* an instance in order to do the encoding or decoding, uses the result and discards the instantiated
* object. What that means in particular is that a self-encoding class shouldn't encode its own state, it
* should encode the state of the object passed to it.
*
*
* Implementation note: the default value provided here is simply an empty string because null
* is not a valid default.
*/
String encoderDecoderName() default "";
/**
* As per {@link #encoderDecoderName()}, but specifying a class literal rather than a fully qualified
* class name.
*
*
* Implementation note: the default value provided here is simply the {@link Encodeable}'s own class,
* because null is not a valid default.
*/
Class encoderDecoderClass() default Encodeable.class;
}