org.hypergraphdb.type

Class JavaTypeSchema

java.lang.Object

org.hypergraphdb.type.JavaTypeSchema

All Implemented Interfaces:

HGTypeSchema<Class<?>>

public class JavaTypeSchema
extends Object
implements HGTypeSchema<Class<?>>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	JavaTypeSchema.ClassToTypeCache

Constructor Summary

Constructors

Constructor and Description
JavaTypeSchema()
JavaTypeSchema(HyperGraph graph)

Method Summary

Methods

Modifier and Type	Method and Description
static URI	classNameToURI(String classname)
static URI	classToURI(Class<?> cl)
void	defineType(URI typeId, HGHandle typeHandle) Construct a new HyperGraphDB type from the specified type identifierURI.
HGAtomType	defineType(URI typeId, HGHandle typeHandle, Class<?> descriptor)
HGHandle	findType(Class<?> clazz)
HGHandle	findType(URI typeId) Return the HGHandle of an existing HyperGraph type that corresponds to the specified type identifier according to this schema.
HGAtomType	fromRuntimeType(HGHandle typeHandle, HGAtomType typeInstance) If a given type is wrapped under a different runtime representation by the HGTypeSchema.toRuntimeType(HGHandle, HGAtomType) method, this method retrieves the underlying default representation as constructed by the type system.
JavaTypeMapper	getJavaTypeFactory()
String	getName() Return the name of this HGTypeSchema.
String	getPredefinedTypes() Return the location of the type configuration file.
Class<?>	getTypeDescriptor(URI typeId) Return the TypeDescriptor corresponding to the passed in type identifier.
void	initialize(HyperGraph graph) Initialize the schema with the HyperGraph instance to which it is bound.
boolean	isPresent(HyperGraph graph)
void	removeType(URI typeId)
void	setPredefinedTypes(String predefinedTypes) Specify the type configuration file to use when bootstrapping the type system.
HGAtomType	toRuntimeType(HGHandle typeHandle, HGAtomType typeInstance) The type schema may wrap a given HyperGraphDB type into a different runtime instance.
URI	toTypeURI(Class<?> javaClass)
URI	toTypeURI(Object object)
static String	uriToClassName(URI uri)

Methods inherited from class java.lang.Object

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

Constructor Detail

JavaTypeSchema

public JavaTypeSchema()

JavaTypeSchema

public JavaTypeSchema(HyperGraph graph)

Method Detail

getJavaTypeFactory

public JavaTypeMapper getJavaTypeFactory()

getPredefinedTypes

public String getPredefinedTypes()

Return the location of the type configuration file. This file can be either a classpath resource or a file on disk or

setPredefinedTypes

public void setPredefinedTypes(String predefinedTypes)

Specify the type configuration file to use when bootstrapping the type system. This file must contain the list of predefined types needed for the normal functioning of a database instance. Each line in this text file is a space separated list of (1) the persistent handle of the type (2) The Java class implementing the HGAtomType interface and optionally (3) one or more Java classes to which the type implementation is associated.

Parameters:

typeConfiguration - The location of the type configuration file. First, an attempt is made to load this location is a classpath resource. Then as a local file. Finally as a remote URL-based resource.

getName

public String getName()

Description copied from interface: HGTypeSchema

Return the name of this HGTypeSchema. The name of a type schema uniquely identifies it.

Specified by:

getName in interface HGTypeSchema<Class<?>>

isPresent

public boolean isPresent(HyperGraph graph)

initialize

public void initialize(HyperGraph graph)

Description copied from interface: HGTypeSchema

Initialize the schema with the HyperGraph instance to which it is bound. A given schema runtime instance is only bound to one database instance.

Specified by:

initialize in interface HGTypeSchema<Class<?>>

defineType

public HGAtomType defineType(URI typeId,
                    HGHandle typeHandle,
                    Class<?> descriptor)

getTypeDescriptor

public Class<?> getTypeDescriptor(URI typeId)

Description copied from interface: HGTypeSchema

Return the TypeDescriptor corresponding to the passed in type identifier.

Specified by:

getTypeDescriptor in interface HGTypeSchema<Class<?>>

Returns:

toRuntimeType

public HGAtomType toRuntimeType(HGHandle typeHandle,
                       HGAtomType typeInstance)

Description copied from interface: HGTypeSchema

The type schema may wrap a given HyperGraphDB type into a different runtime instance. This is useful when atoms, and therefore in all likelihood their types as well, have different runtime representations depending on the current type schema in effect. Every time a type is loaded by the type system, the toRuntimeType of the current type schema is called to give it a change to provide a different representation.

Specified by:

toRuntimeType in interface HGTypeSchema<Class<?>>

Parameters:

typeHandle - The HGHandle of the type.

typeInstance - The type instance constructed by default from the type system.

Returns:

A (possibly) different runtime representation of the type.

fromRuntimeType

public HGAtomType fromRuntimeType(HGHandle typeHandle,
                         HGAtomType typeInstance)

Description copied from interface: HGTypeSchema

If a given type is wrapped under a different runtime representation by the HGTypeSchema.toRuntimeType(HGHandle, HGAtomType) method, this method retrieves the underlying default representation as constructed by the type system.

Specified by:

fromRuntimeType in interface HGTypeSchema<Class<?>>

Parameters:

typeHandle - The HGHandle of the type.

typeInstance - A modified runtime representation of the type.

Returns:

toTypeURI

public URI toTypeURI(Object object)

Specified by:

toTypeURI in interface HGTypeSchema<Class<?>>

findType

public HGHandle findType(URI typeId)

Description copied from interface: HGTypeSchema

Return the HGHandle of an existing HyperGraph type that corresponds to the specified type identifier according to this schema.

Specified by:

findType in interface HGTypeSchema<Class<?>>

Parameters:

typeId - The identifier of the type. The identifier must be valid within this schema. In particular the schema part of the URI must match this schema's name.

Returns:

The HGHandle of the HyperGraph type if it exists or null if it doesn't.

findType

public HGHandle findType(Class<?> clazz)

removeType

public void removeType(URI typeId)

Specified by:

removeType in interface HGTypeSchema<Class<?>>

toTypeURI

public URI toTypeURI(Class<?> javaClass)

Specified by:

toTypeURI in interface HGTypeSchema<Class<?>>

uriToClassName

public static String uriToClassName(URI uri)

classNameToURI

public static URI classNameToURI(String classname)

classToURI

public static URI classToURI(Class<?> cl)

defineType

public void defineType(URI typeId,
              HGHandle typeHandle)

Description copied from interface: HGTypeSchema

Construct a new HyperGraphDB type from the specified type identifierURI. It is the responsibility of the schema implementation to find the correct TypeDescriptor for that identifier. The schema may return an existing HyperGraph type that corresponds to the identifier is it finds one already in the database. However, types, like other atoms, are not guaranteed to be immutable. Therefore, a schema does not "own" a HyperGraph type and the latter may be modified outside of its control.

Specified by:

defineType in interface HGTypeSchema<Class<?>>

Parameters:

typeId - The identifier of the type. The identifier must be valid within this schema. In particular the schema part of the URI must match this schema's name.