info.archinnov.achilles.annotations

Annotation Type Immutable

@Retention(value=RUNTIME)
 @Target(value=TYPE)
 @Documented
public @interface Immutable

Mark an entity/udt/view as immutable. The immutable entity should comply to the following rules

1. all fields should have public and final modifiers
2. have no getter nor setter
3. have exactly one non-default constructor that:
   • has as many argument as there are fields
   • each argument should have the same type as its corresponding field (for primitive types, we rely on autoboxing so you can use 'Long' or 'long' for example, it does not matter)
   • each argument name should match field name

Example of correct mapping:

 @Table
 @Immutable
 public class MyImmutableEntity {

     @PartitionKey
     public final Long sensorId;

     @ClusteringColumn
     public final Date date;

     @Column
     public final Double value;

     //Correct non-default constructor with matching field name and type
     public MyImmutableEntity(long sensorId, Date date, Double value) {
         this.sensorId = sensorId;
         this.date = date;
         this.value = value;
     }

     // NO GETTER NOR SETTER !!!!!!!!!!!!!!!
 }
 

Example of wrong mapping because constructor argument name does not match field name:

 @Table
 @Immutable
 public class MyImmutableEntity {

     @PartitionKey
     public final Long sensorId;

     @ClusteringColumn
     public final Date date;

     @Column
     public final Double value;

     //Incorrect, there is no field name "sensor_id" !!
     public MyImmutableEntity(long sensor_id, Date date, Double value) {
         this.sensorId = sensorId;
         this.date = date;
         this.value = value;
     }

     // NO GETTER NOR SETTER !!!!!!!!!!!!!!!
 }
 

Example of wrong mapping because constructor argument type does not match field type:

 @Table
 @Immutable
 public class MyImmutableEntity {

     @PartitionKey
     public final Long sensorId;

     @ClusteringColumn
     public final Date date;

     @Column
     public final Double value;

     //Incorrect, field sensorId is of type Long, not String !!
     public MyImmutableEntity(String sensor_id, Date date, Double value) {
         this.date = date;
         this.value = value;
     }

     // NO GETTER NOR SETTER !!!!!!!!!!!!!!!
 }
 

See Also:

@Immutable