org.springframework.data.rest.core.support

Interface EntityLookup<T>

All Superinterfaces:

org.springframework.plugin.core.Plugin<Class<?>>

All Known Implementing Classes:

EntityLookupSupport

public interface EntityLookup<T>
extends org.springframework.plugin.core.Plugin<Class<?>>

SPI to customize which property of an entity is used as unique identifier and how the entity instance is looked up from the backend. Prefer to extend EntityLookupSupport to let the generics declaration be used for the Plugin.supports(Object) method automatically.

Since:

2.5

Author:

Oliver Gierke

See Also:

EntityLookupSupport, DefaultSelfLinkProvider

Method Summary

Modifier and Type	Method and Description
Serializable	getResourceIdentifier(T entity) Returns the property of the given entity that shall be used to uniquely identify it.
Object	lookupEntity(Serializable id) Returns the entity instance to be used if an entity with the given identifier value is requested.

Methods inherited from interface org.springframework.plugin.core.Plugin

supports

Method Detail

getResourceIdentifier

Serializable getResourceIdentifier(T entity)

Returns the property of the given entity that shall be used to uniquely identify it. If no EntityLookup is defined for a particular type, a standard identifier lookup mechanism (i.e. the datastore identifier) will be used to eventually create an identifying URI.

Parameters:

entity - will never be null.

Returns:

must not be null.

lookupEntity

Object lookupEntity(Serializable id)

Returns the entity instance to be used if an entity with the given identifier value is requested. Implementations will usually forward the call to a repository method explicitly and can assume the given value be basically the value they returned in getResourceIdentifier(Object).

Implementations are free to return null to indicate absence of a value or wrap the result into any generally supported Optional type.

Parameters:

id - will never be null.

Returns:

can be null.