com.datastax.oss.driver.api.mapper.annotations

Annotation Type SetEntity

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

Annotates a Dao method that fills a core driver data structure from an instance of an Entity class.

Example:

 public interface ProductDao {
   @SetEntity
   BoundStatement bind(Product product, BoundStatement boundStatement);
 }
 

The generated code will set each entity property on the target, such as:

 boundStatement = boundStatement.set("id", product.getId(), UUID.class);
 boundStatement = boundStatement.set("description", product.getDescription(), String.class);
 ...
 

It does not perform a query. Instead, those methods are intended for cases where you will execute the query yourself, and just need the conversion logic.

Parameters

The method must have two parameters: one is the entity instance, the other must be a subtype of SettableByName (the most likely candidates are BoundStatement, BoundStatementBuilder and UdtValue). Note that you can't use SettableByName itself.

The order of the parameters does not matter.

Return type

The method can either be void, or return the exact same type as its settable parameter.

 @SetEntity
 void bind(Product product, UdtValue udtValue);

 @SetEntity
 void bind(Product product, BoundStatementBuilder builder);
 

Note that if the settable parameter is immutable, the method should return a new instance, because the generated code won't be able to modify the argument in place. This is the case for BoundStatement, which is immutable in the driver:

 // Wrong: statement won't be modified
 @SetEntity
 void bind(Product product, BoundStatement statement);

 // Do this instead:
 @SetEntity
 BoundStatement bind(Product product, BoundStatement statement);
 

If you use a void method with BoundStatement, the mapper processor will issue a compile-time warning.

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
NullSavingStrategy	nullSavingStrategy How to handle null entity properties.

Element Detail

nullSavingStrategy

public abstract NullSavingStrategy nullSavingStrategy

How to handle null entity properties.

This defaults either to the DAO-level strategy (if set), or NullSavingStrategy.DO_NOT_SET.

Default:

com.datastax.oss.driver.api.mapper.entity.saving.NullSavingStrategy.DO_NOT_SET