Package com.levigo.jadice.web.transport.shared.messaging

Class PolymorphicMapper<T,D>

java.lang.Object

com.levigo.jadice.web.transport.shared.messaging.PolymorphicMapper<T,D>

Type Parameters:

T - Interface or abstract class used as a semantical base

D - JSON implementation used (JavaScriptObject for client, ObjectNode for server)

Direct Known Subclasses:

ClientPolymorphicMapper, InstructionMapper, PageMapper, PageSegmentHandleMapper, PageSegmentHandleMapper, ServerPolymorphicMapper, SourceMapper

public abstract class PolymorphicMapper<T,D>
extends Object

This class solves the problem of managing class hierarchies when mapping objects to DTOs and can be extended for any given base class.

In the future, messages will be sent from and received in the frontend in pure JS/TS, which does not allow us to use shared classes anymore. Also, many of the complex structures can be represented far simpler in JSON without requiring class hierarchies at all.

e.g. {type: "URL", url: "https://[...].pdf"} as an equivalent to a "UrlSource" class, extending from Source.

Therefore, we want an independent DTO mapping. While this might seem redundant as long as we are working with GWT, there will be no need for such a process in the frontend in the long term - this is just glue code to allow the deprecated GWT webtoolkit to interface seamlessly with the new API.

TODO: Update this comment as soon as GWT is fully gone. :)

Field Summary

Fields

Modifier and Type	Field	Description
protected final List<String>	ignoreList
protected final HashMap<String,Mapping<D,T>>	mapFromDTO
protected final HashMap<Class<? extends T>,DTODescriptor<T,D>>	mapToDTO

Constructor Summary

Constructors

Constructor	Description
PolymorphicMapper()

Method Summary

Modifier and Type	Method	Description
protected Class<? extends T>	extractClass(T object)
String	getType(T object)
boolean	isClassRegistered(Class<?> clazz)
T	mapFromDTO(String type, D payload)
protected T	mapFromDTODefault(String type, D payload)
D	mapToDTO(T object)
protected D	mapToDTODefault(T object)
void	registerIgnore(Class<?> clazz)	Registers a class that should not be serialized
void	registerMapping(String type, Class<? extends T> clazz, Mapping<T,D> toDTOMapping, Mapping<D,T> fromDTOMapping)

Methods inherited from class java.lang.Object

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

Field Details

mapFromDTO

protected final HashMap<String,Mapping<D,T>> mapFromDTO

mapToDTO

protected final HashMap<Class<? extends T>,DTODescriptor<T,D>> mapToDTO

ignoreList

protected final List<String> ignoreList

Constructor Details

PolymorphicMapper

public PolymorphicMapper()

Method Details

registerMapping

public void registerMapping(String type,
 Class<? extends T> clazz,
 Mapping<T,D> toDTOMapping,
 Mapping<D,T> fromDTOMapping)

registerIgnore

public void registerIgnore(Class<?> clazz)

Registers a class that should not be serialized

Parameters:

clazz - the Class to ignore

isClassRegistered

public boolean isClassRegistered(Class<?> clazz)

extractClass

protected Class<? extends T> extractClass(T object)

mapToDTO

public D mapToDTO(T object)

getType

public String getType(T object)

mapFromDTO

public T mapFromDTO(String type,
 D payload)

mapFromDTODefault

protected T mapFromDTODefault(String type,
 D payload)

mapToDTODefault

protected D mapToDTODefault(T object)