org.eiichiro.acidhouse

Interface Filter<T>

All Known Implementing Classes:

ComparableFilter, InFilter

public interface Filter<T>

Filter qualifies the entities to which a Command is applied. You can get Filter instances from metamodel property and can pass to GetList, GetScalar, Update and Delete's filter(Filter...) method. As an example in App Engine:

 import org.eiichiro.acidhouse.Session;
 import org.eiichiro.acidhouse.appengine.AppEngineDatastoreSession;
 ...
 
 // Creating 'Session' instance.
 Session session = new AppEngineDatastoreSession();
 // Getting metamodel instance of 'Entity3' class.
 Entity3_ entity3_ = Metamodels.metamodel(Entity3.class);
 // Qualifying entities which their 'entity1.i' proerty is greater than or 
 // equal to 13, and 15 or 16.
 List<Entity3> entity3s = session
                .get(entity3_)
                .filter(entity3_.entity1.i.greaterThanOrEqualTo(13), 
                        entity3_.entity1.i.in(15, 16))
                .execute();
 

Author:

Eiichiro Uchiumi

See Also:

ComparableProperty, Metamodel, GetList, GetScalar, Update, Delete

Method Summary

Methods

Modifier and Type	Method and Description
boolean	matches(Object entity) Indicates whether the specified entity matches to this Filter or not.
Property<?,T>	property() Returns the metamodel Property this Filter is applied to.

Method Detail

property

Property<?,T> property()

Returns the metamodel Property this Filter is applied to.

Returns:

The metamodel Property this Filter is applied to.

matches

boolean matches(Object entity)

Indicates whether the specified entity matches to this Filter or not. This method is invoked by Command implementation for in-memory filtering.

Parameters:

entity - The entity to be filtered.

Returns:

Whether the specified entity matches to this Filter or not.