org.seedstack.business.api.interfaces.assembler

Annotation Type MatchingEntityId

@Retention(value=RUNTIME)
@Target(value=METHOD)
public @interface MatchingEntityId

This annotation allows the use of the fromRepository() method of the assembler DSL. If you don't use this DSL feature, this annotated is unnecessary.

It binds the DTO annotated method to the aggregate root id. If the id is a value object, it binds the method to one of the constructor parameters. This allows the assembler DSL to find (or create) the aggregate root id in order to load the aggregate root from the repository.

It also handle the case of a DTO assembled from a tuple of aggregate roots.

Case 1: Basic use case.

 public class OrderDto {

     @MatchingEntityId
     public int getId() {...}
 }

 public class OrderAssembler extends BaseTupleAssembler<Order, OrderDto> { ... }

 public class Order {

     private int orderId;

     public Integer getEntityId() {
         return orderId;
     }
 }
 

Case 1: Basic use case.

 public class CustomerDto {

     @MatchingEntityId(index = 0)
     public String getFirstName() {...}

     @MatchingEntityId(index = 1)
     public String getLastName() {...}

     // No need for annotation here as the birth date is not part of the customer id
     public Date getBirthDate() {...}
 }

 public class RecipeAssembler extends BaseAssembler<Customer, CustomerDto> { ... }

 public class CustomerId {
     public CustomerId(String firstName, String lastName) {...}
 }
 

Case 2: The DTO is an assembly of multiple aggregates.

 public class RecipeDto {

     @MatchingEntityId(index = 0, typeIndex = 0)
     public String getCustomerFirstName() {...}

     @MatchingEntityId(index = 1, typeIndex = 0)
     public String getCustomerLastName() {...}

     @MatchingEntityId(typeIndex = 1) // no need for index as OrderId is not a value object
     public int getOrderId() {...}
 }

 public class RecipeAssembler extends BaseTupleAssembler<Pair<Customer, Order>, RecipeDto> { ... }

 public class CustomerId {
     public CustomerId(String firstName, String lastName) {...}
 }

 public class Order {

     private int orderId;

     public Integer getEntityId() {
         return orderId;
     }
 }
 

Author:

epo.jemba@ext.mpsa.com

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
int	index If the aggregate root id is composite, i.e it is a value object, this method indicates constructor parameter of the value object associated to the annotated method.
int	typeIndex When using a tuple assembler, i.e. when assembling a DTO to tuple of aggregate roots.

Element Detail

index

public abstract int index

If the aggregate root id is composite, i.e it is a value object, this method indicates constructor parameter of the value object associated to the annotated method.

Returns:

the parameter index in the id constructor.

Default:

-1

typeIndex

public abstract int typeIndex

When using a tuple assembler, i.e. when assembling a DTO to tuple of aggregate roots. This index indicates to which aggregate root this id belongs.

Returns:

the aggregate index

See Also:

BaseTupleAssembler

Default:

-1