Package com.googlecode.objectify.impl.translate

Class CollectionTranslatorFactory

java.lang.Object

com.googlecode.objectify.impl.translate.CollectionTranslatorFactory

All Implemented Interfaces:

TranslatorFactory<Collection<Object>,List<? extends com.google.cloud.datastore.Value<?>>>

public class CollectionTranslatorFactory
extends Object
implements TranslatorFactory<Collection<Object>,List<? extends com.google.cloud.datastore.Value<?>>>

Translator which can load things into a collection field. Those things are themselves translated.

This translator is clever about recycling an existing collection in the POJO field when loading. That way a collection that has been initialized with a sort (or other data) will remain intact.

Note that empty or null collections are not stored in the datastore, and null values for the collection field are ignored when they are loaded from the Entity. This is because the datastore doesn't store empty collections, and storing null fields will confuse filtering for actual nulls in the collection contents.

Author:

Jeff Schnitzer

Constructor Summary

Constructors

Constructor	Description
CollectionTranslatorFactory()

Method Summary

Modifier and Type	Method	Description
Translator<Collection<Object>,List<? extends com.google.cloud.datastore.Value<?>>>	create(TypeKey<Collection<Object>> tk, CreateContext ctx, Path path)	Create a translator for a type.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CollectionTranslatorFactory

public CollectionTranslatorFactory()

Method Detail

create

public Translator<Collection<Object>,List<? extends com.google.cloud.datastore.Value<?>>> create(TypeKey<Collection<Object>> tk,
                                                                                                       CreateContext ctx,
                                                                                                       Path path)

Description copied from interface: TranslatorFactory

Create a translator for a type.

Specified by:

create in interface TranslatorFactory<Collection<Object>,List<? extends com.google.cloud.datastore.Value<?>>>

Parameters:

tk - defines the type which is to be translated

path - is where this type was discovered, important for logging and exceptions

Returns:

null if this factory does not know how to deal with that situation.