org.hypergraphdb.type

Interface JavaTypeMapper

All Superinterfaces:

HGGraphHolder

All Known Implementing Classes:

DefaultJavaTypeMapper, JavaObjectMapper, JavaTypeFactory

public interface JavaTypeMapper
extends HGGraphHolder

A JavaTypeMapper is used to create HyperGraphDB type out of Java classes and to provide appropriate run-time representations.

When the type an atom of an unknown Java class is first requested, the type system must create an appropriate HyperGraphDB type using Java reflection on the class. The HyperGraphDB type should be portable and potentially usable from other languages such as C++. For example a plain Java bean is usually translated into the general RecordType.

The HyperGraphDB type, being general, doesn't have to necessarily create objects of the original Java class. In other words

Author:

Borislav Iordanov

Method Summary

Methods

Modifier and Type	Method and Description
HGAtomType	defineHGType(Class<?> javaClass, HGHandle typeHandle) Create a new HyperGraphDB type for the given Java class.
HGAtomType	getJavaBinding(HGHandle typeHandle, HGAtomType hgType, Class<?> javaClass) Create a type wrapper for a given raw HyperGraphDB type.

Methods inherited from interface org.hypergraphdb.HGGraphHolder

setHyperGraph

Method Detail

defineHGType

HGAtomType defineHGType(Class<?> javaClass,
                      HGHandle typeHandle)

Create a new HyperGraphDB type for the given Java class. The HGHandle of the type pre-created and provided as a parameter.

This method should return a brand new HGAtomType that will subsequently be saved as a type atom with handle typeHandle and associated with the javaClass class. The method should return null in case it cannot (or it determines that it should not) create a HGAtomType. In the case the JavaTypeFactory will move on to try the next of the registered type mappers.

Parameters:

javaClass -

typeHandle -

Returns:

A newly created HGAtomType corresponding to the passed in Java class or null if such a type could not be created.

getJavaBinding

HGAtomType getJavaBinding(HGHandle typeHandle,
                        HGAtomType hgType,
                        Class<?> javaClass)

Create a type wrapper for a given raw HyperGraphDB type. The type wrapper should work with the regular Java runtime instance of an atom and use the underlying HG type for actual storage and retrieval.

Parameters:

typeHandle - The handle of the type being wrapped.

hgType - The HyperGraphDB type instance to be wrapped

javaClass - The Java class corresponding to this HyperGraphDB type.

Returns:

The type wrapper or null if