Defining Entities

This is the manual for older MicroStream versions (Version < 5.0).

The new documentation (Version >= 5.0) is located at:

https://docs.microstream.one/

The entity types are just simple interfaces with value methods, which have following requirements:

A return type, no void
No parameters
No type parameters
No declared checked exceptions

You are not limited otherwise. Use any types you want. Inheritance and generics are supported as well.

Entities

public interface Beeing<B>
{
	public B partner();
}

public interface Named
{
	public String name();
}

public interface Animal extends Beeing<Animal>, Entity
{
	public String species();
}

public interface Pet extends Animal, Named
{
}

public interface Human extends Beeing<Human>, Named, Entity
{
}

There is one base type (Beeing), one feature interface (Named) and three entities (Animal, Pet, Human).

Generated Code

The code generator takes care of the three entities, and its output looks like this:

public class AnimalEntity extends EntityLayerIdentity implements Animal
{
	protected AnimalEntity()
	{
		super();
	}

	@Override
	protected Animal entityData()
	{
		return (Animal)super.entityData();
	}

	@Override
	public final String species()
	{
		return this.entityData().species();
	}

	@Override
	public final Animal partner()
	{
		return this.entityData().partner();
	}
}

public class AnimalData extends EntityData implements Animal
{
	private final String species;
	private final Animal partner;

	protected AnimalData(final Animal entity,
		final String species,
		final Animal partner)
	{
		super(entity);

		this.species = species;
		this.partner = partner;
	}

	@Override
	public String species()
	{
		return this.species;
	}

	@Override
	public Animal partner()
	{
		return this.partner;
	}
}

public interface AnimalCreator extends Entity.Creator<Animal, AnimalCreator>
{
	public AnimalCreator species(String species);

	public AnimalCreator partner(Animal partner);

	public static AnimalCreator New()
	{
		return new Default();
	}

	public static AnimalCreator New(final Animal other)
	{
		return new Default().copy(other);
	}

	public class Default
		extends Entity.Creator.Abstract<Animal, AnimalCreator>
		implements AnimalCreator
	{
		private String species;
		private Animal partner;

		protected Default()
		{
			super();
		}

		@Override
		public AnimalCreator species(final String species)
		{
			this.species = species;
			return this;
		}

		@Override
		public AnimalCreator partner(final Animal partner)
		{
			this.partner = partner;
			return this;
		}

		@Override
		protected EntityLayerIdentity createEntityInstance()
		{
			return new AnimalEntity();
		}

		@Override
		public Animal createData(final Animal entityInstance)
		{
			return new AnimalData(entityInstance,
				this.species,
				this.partner);
		}

		@Override
		public AnimalCreator copy(final Animal other)
		{
			final Animal data = Entity.data(other);
			this.species = data.species();
			this.partner = data.partner();
			return this;
		}
	}
}

public interface AnimalUpdater extends Entity.Updater<Animal, AnimalUpdater>
{
	public static boolean setSpecies(final Animal animal, final String species)
	{
		return New(animal).species(species).update();
	}

	public static boolean setPartner(final Animal animal, final Animal partner)
	{
		return New(animal).partner(partner).update();
	}

	public AnimalUpdater species(String species);

	public AnimalUpdater partner(Animal partner);

	public static AnimalUpdater New(final Animal animal)
	{
		return new Default(animal);
	}

	public class Default
		extends Entity.Updater.Abstract<Animal, AnimalUpdater>
		implements AnimalUpdater
	{
		private String species;
		private Animal partner;

		protected Default(final Animal animal)
		{
			super(animal);
		}

		@Override
		public AnimalUpdater species(final String species)
		{
			this.species = species;
			return this;
		}

		@Override
		public AnimalUpdater partner(final Animal partner)
		{
			this.partner = partner;
			return this;
		}

		@Override
		public Animal createData(final Animal entityInstance)
		{
			return new AnimalData(entityInstance,
				this.species,
				this.partner);
		}

		@Override
		public AnimalUpdater copy(final Animal other)
		{
			final Animal data = Entity.data(other);
			this.species = data.species();
			this.partner = data.partner();
			return this;
		}
	}
}

public class PetEntity extends EntityLayerIdentity implements Pet
{
	protected PetEntity()
	{
		super();
	}

	@Override
	protected Pet entityData()
	{
		return (Pet)super.entityData();
	}

	@Override
	public final String species()
	{
		return this.entityData().species();
	}

	@Override
	public final Animal partner()
	{
		return this.entityData().partner();
	}

	@Override
	public final String name()
	{
		return this.entityData().name();
	}
}

public class PetData extends EntityData implements Pet
{
	private final String species;
	private final Animal partner;
	private final String name   ;

	protected PetData(final Pet entity,
		final String species,
		final Animal partner,
		final String name   )
	{
		super(entity);

		this.species = species;
		this.partner = partner;
		this.name    = name   ;
	}

	@Override
	public String species()
	{
		return this.species;
	}

	@Override
	public Animal partner()
	{
		return this.partner;
	}

	@Override
	public String name()
	{
		return this.name;
	}
}

public interface PetCreator extends Entity.Creator<Pet, PetCreator>
{
	public PetCreator species(String species);

	public PetCreator partner(Animal partner);

	public PetCreator name(String name);

	public static PetCreator New()
	{
		return new Default();
	}

	public static PetCreator New(final Pet other)
	{
		return new Default().copy(other);
	}

	public class Default
		extends Entity.Creator.Abstract<Pet, PetCreator>
		implements PetCreator
	{
		private String species;
		private Animal partner;
		private String name   ;

		protected Default()
		{
			super();
		}

		@Override
		public PetCreator species(final String species)
		{
			this.species = species;
			return this;
		}

		@Override
		public PetCreator partner(final Animal partner)
		{
			this.partner = partner;
			return this;
		}

		@Override
		public PetCreator name(final String name)
		{
			this.name = name;
			return this;
		}

		@Override
		protected EntityLayerIdentity createEntityInstance()
		{
			return new PetEntity();
		}

		@Override
		public Pet createData(final Pet entityInstance)
		{
			return new PetData(entityInstance,
				this.species,
				this.partner,
				this.name   );
		}

		@Override
		public PetCreator copy(final Pet other)
		{
			final Pet data = Entity.data(other);
			this.species = data.species();
			this.partner = data.partner();
			this.name    = data.name   ();
			return this;
		}
	}
}

public interface PetUpdater extends Entity.Updater<Pet, PetUpdater>
{
	public static boolean setSpecies(final Pet pet, final String species)
	{
		return New(pet).species(species).update();
	}

	public static boolean setPartner(final Pet pet, final Animal partner)
	{
		return New(pet).partner(partner).update();
	}

	public static boolean setName(final Pet pet, final String name)
	{
		return New(pet).name(name).update();
	}

	public PetUpdater species(String species);

	public PetUpdater partner(Animal partner);

	public PetUpdater name(String name);

	public static PetUpdater New(final Pet pet)
	{
		return new Default(pet);
	}

	public class Default
		extends Entity.Updater.Abstract<Pet, PetUpdater>
		implements PetUpdater
	{
		private String species;
		private Animal partner;
		private String name   ;

		protected Default(final Pet pet)
		{
			super(pet);
		}

		@Override
		public PetUpdater species(final String species)
		{
			this.species = species;
			return this;
		}

		@Override
		public PetUpdater partner(final Animal partner)
		{
			this.partner = partner;
			return this;
		}

		@Override
		public PetUpdater name(final String name)
		{
			this.name = name;
			return this;
		}

		@Override
		public Pet createData(final Pet entityInstance)
		{
			return new PetData(entityInstance,
				this.species,
				this.partner,
				this.name   );
		}

		@Override
		public PetUpdater copy(final Pet other)
		{
			final Pet data = Entity.data(other);
			this.species = data.species();
			this.partner = data.partner();
			this.name    = data.name   ();
			return this;
		}
	}
}

public class HumanEntity extends EntityLayerIdentity implements Human
{
	protected HumanEntity()
	{
		super();
	}

	@Override
	protected Human entityData()
	{
		return (Human)super.entityData();
	}

	@Override
	public final Human partner()
	{
		return this.entityData().partner();
	}

	@Override
	public final String name()
	{
		return this.entityData().name();
	}
}

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