com.facebook.presto.jdbc.internal.jackson.annotation.JsonIdentityInfo Maven / Gradle / Ivy
package com.facebook.presto.jdbc.internal.jackson.annotation;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Annotation used for indicating that values of annotated type
* or property should be serializing so that instances either
* contain additional object identifier (in addition actual object
* properties), or as a reference that consists of an object id
* that refers to a full serialization. In practice this is done
* by serializing the first instance as full object and object
* identity, and other references to the object as reference values.
*
* There are two main approaches to generating object identifier:
* either using a generator (either one of standard ones, or a custom
* generator), or using a value of a property. The latter case is
* indicated by using a placeholder generator marker
* {@link ObjectIdGenerators.PropertyGenerator}; former by using explicit generator.
* Object id has to be serialized as a property in case of POJOs;
* object identity is currently NOT support for JSON Array types
* (Java arrays or Lists) or Java Map types.
*
* Finally, note that generator type of {@link ObjectIdGenerators.None}
* indicates that no Object Id should be included or used: it is included
* to allow suppressing Object Ids using mix-in annotations.
*
* @since 2.0
*/
@Target({ElementType.ANNOTATION_TYPE, ElementType.TYPE,
ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
@Retention(RetentionPolicy.RUNTIME)
@JacksonAnnotation
public @interface JsonIdentityInfo
{
/**
* Name of JSON property in which Object Id will reside: also,
* if "from property" marker generator is used, identifies
* property that will be accessed to get type id.
* If a property is used, name must match its external
* name (one defined by annotation, or derived from accessor
* name as per Java Bean Introspection rules).
*
* Default value is @id.
*/
public String property() default "@id";
/**
* Generator to use for producing Object Identifier for objects:
* either one of pre-defined generators from
* {@link ObjectIdGenerator}, or a custom generator.
* Defined as class to instantiate.
*
* Note that special type
* {@link ObjectIdGenerators.None}
* can be used to disable inclusion of Object Ids.
*/
public Class> generator();
/**
* Resolver to use for producing POJO from Object Identifier.
*
* Default value is {@link SimpleObjectIdResolver}
*
* @since 2.4
*/
public Class resolver() default SimpleObjectIdResolver.class;
/**
* Scope is used to define applicability of an Object Id: all ids
* must be unique within their scope; where scope is defined
* as combination of this value and generator type.
* Comparison is simple equivalence, meaning that both type
* generator type and scope class must be the same.
*
* Scope is used for determining how many generators are needed;
* more than one scope is typically only needed if external Object Ids
* have overlapping value domains (i.e. are only unique within some
* limited scope)
*/
public Class scope() default Object.class;
}