CosId Annotation Support

CosId provides annotation support for automatic ID generation and injection in your domain objects.

@CosId Annotation

The @CosId annotation marks fields or classes for CosId ID generation.

@Target({ElementType.FIELD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
public @interface CosId {
    /**
     * Gets the ID generator name.
     *
     * @return the generator name
     */
    String value() default IdGeneratorProvider.SHARE;

    /**
     * Gets the ID field name (for type-level annotation).
     *
     * @return the field name
     */
    String field() default DEFAULT_FIELD;
}

Usage

Field-Level Annotation

Mark a field directly with @CosId:

public class Order {
    @CosId
    private Long orderId;
    private Long userId;
}

Type-Level Annotation

Mark a class and specify the field name:

@CosId(value = "orderId")
public class Order {
    private Long orderId;
    private Long userId;
}

CosIdAccessor

CosIdAccessor provides automatic ID injection for objects. It combines multiple capabilities:

• CosIdGetter: Getting ID values from objects
• CosIdSetter: Setting ID values on objects
• IdMetadata: Providing metadata about ID fields
• EnsureId: Ensuring objects have IDs assigned

Supported ID Types

CosId supports the following ID types:

• String
• Long / long
• Integer / int

Integration with MyBatis

CosId-MyBatis integration automatically injects IDs when inserting entities:

@Mapper
public interface OrderRepository {
    @Insert("insert into t_table (id) value (#{id});")
    void insert(Order order);
}

public class Order {
    @CosId(value = "order")
    private Long orderId;
}

When orderRepository.insert(order) is called, the ID is automatically generated and set.

Parser Implementation

CosId uses CosIdAccessorParser to parse @CosId annotations and create CosIdAccessor instances that handle ID generation and injection.