com.fasterxml.jackson.annotation
Class ObjectIdGenerator<T>

java.lang.Object
  com.fasterxml.jackson.annotation.ObjectIdGenerator<T>

Type Parameters:

T - Type of Object Identifiers produced.

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

ObjectIdGenerators.IntSequenceGenerator, ObjectIdGenerators.None, ObjectIdGenerators.PropertyGenerator, ObjectIdGenerators.StringIdGenerator, ObjectIdGenerators.UUIDGenerator

public abstract class ObjectIdGenerator<T>
extends Object
implements Serializable

Definition of API used for constructing Object Identifiers (as annotated using JsonIdentityInfo). Also defines factory methods used for creating instances for serialization, deserialization.

See Also:

Serialized Form

Nested Class Summary

static class

ObjectIdGenerator.IdKey Simple key class that can be used as a key for ObjectId-to-POJO mappings, when multiple ObjectId types and scopes are used.

Constructor Summary

ObjectIdGenerator()

Method Summary

abstract boolean	canUseFor(ObjectIdGenerator<?> gen) Method called to check whether this generator instance can be used for Object Ids of specific generator type and scope; determination is based by passing a configured "blueprint" (prototype) instance; from which the actual instances are created (using newForSerialization(java.lang.Object)).
abstract ObjectIdGenerator<T>	forScope(Class<?> scope) Factory method to create a blueprint instance for specified scope.
abstract T	generateId(Object forPojo) Method used for generating a new Object Identifier to serialize for given POJO.
abstract Class<?>	getScope()
boolean	isValidReferencePropertyName(String name, Object parser) Accessor that may be called (after verifying (via maySerializeAsObject()) whether given name
abstract ObjectIdGenerator.IdKey	key(Object key) Method for constructing key to use for ObjectId-to-POJO maps.
boolean	maySerializeAsObject() Accessor that needs to be overridden to return true if the Object Id may be serialized as JSON Object; used by, for example, JSOG handling.
abstract ObjectIdGenerator<T>	newForSerialization(Object context) Factory method called to create a new instance to use for serialization: needed since generators may have state (next id to produce).

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ObjectIdGenerator

public ObjectIdGenerator()

Method Detail

getScope

public abstract Class<?> getScope()

canUseFor

public abstract boolean canUseFor(ObjectIdGenerator<?> gen)

Method called to check whether this generator instance can be used for Object Ids of specific generator type and scope; determination is based by passing a configured "blueprint" (prototype) instance; from which the actual instances are created (using newForSerialization(java.lang.Object)).

Returns:

True if this instance can be used as-is; false if not

maySerializeAsObject

public boolean maySerializeAsObject()

Accessor that needs to be overridden to return true if the Object Id may be serialized as JSON Object; used by, for example, JSOG handling. The reason accessor is needed is because handling such Object Ids is more complex and may incur additional buffering or performance overhead, avoiding of which makes sense for common case of scalar object ids (or native object ids some formats support).

Default implementation returns false, so needs to be overridden by Object-producing generators.

Since:

2.5

isValidReferencePropertyName

public boolean isValidReferencePropertyName(String name,
                                            Object parser)

Accessor that may be called (after verifying (via maySerializeAsObject()) whether given name

Parameters:

name - Name of property to check

parser - Parser that points to property name, in case generator needs further verification (note: untyped, because JsonParser is defined in `jackson-core`, and this package does not depend on it).

Since:

2.5

forScope

public abstract ObjectIdGenerator<T> forScope(Class<?> scope)

Factory method to create a blueprint instance for specified scope. Generators that do not use scope may return 'this'.

newForSerialization

public abstract ObjectIdGenerator<T> newForSerialization(Object context)

Factory method called to create a new instance to use for serialization: needed since generators may have state (next id to produce).

Note that actual type of 'context' is com.fasterxml.jackson.databind.SerializerProvider, but can not be declared here as type itself (as well as call to this object) comes from databind package.

Parameters:

context - Serialization context object used (of type com.fasterxml.jackson.databind.SerializerProvider; may be needed by more complex generators to access contextual information such as configuration.

key

public abstract ObjectIdGenerator.IdKey key(Object key)

Method for constructing key to use for ObjectId-to-POJO maps.

generateId

public abstract T generateId(Object forPojo)

Method used for generating a new Object Identifier to serialize for given POJO.

Parameters:

forPojo - POJO for which identifier is needed

Returns:

Object Identifier to use.