org.datanucleus.store.types

Interface TypeManager

All Known Implementing Classes:

TypeManagerImpl

public interface TypeManager

Registry of java type support. Provides information applicable to all datastores for how a field of a class is treated; whether it is by default persistent, whether it is by default embedded, whether it is in the DFG, and if it has a wrapper for SCO operations. Also stores whether the type can be converted to/from a String (for datastores that don't provide storage natively). Uses the plugin mechanism extension-point "org.datanucleus.java_type".

Method Summary

Modifier and Type	Method and Description
void	close()
SCO	createSCOInstance(ObjectProvider ownerOP, AbstractMemberMetaData mmd, Class instantiatedType, Object value, boolean replaceField) Method to create a new SCO wrapper for the specified member.
String[]	filterOutSupportedSecondClassNames(String[] inputClassNames) Convenience method to filter out any supported classes from a list.
TypeConverter	getAutoApplyTypeConverterForType(Class memberType) Method to return a TypeConverter that should be applied by default for the specified java (member) type.
ContainerAdapter	getContainerAdapter(Object container) Convenience method to obtain the ContainerAdapter using the container object instance
<H extends ContainerHandler> H	getContainerHandler(Class containerClass) Obtains the registered ContainerHandler for the given containerClass.
Class	getDatastoreTypeForTypeConverter(TypeConverter conv, Class memberType) Method to return the datastore type for the specified TypeConverter.
TypeConverter	getDefaultTypeConverterForType(Class memberType) Accessor for the default type converter for the provided Java type.
Class	getMemberTypeForTypeConverter(TypeConverter conv, Class datastoreType) Method to return the member type for the specified TypeConverter.
Set<String>	getSupportedSecondClassTypes() Accessor for the supported second-class Types.
TypeConverter	getTypeConverterForName(String converterName) Accessor for the type converter with the provided name.
TypeConverter	getTypeConverterForType(Class memberType, Class datastoreType) Accessor for the type converter for the provided Java type and its datastore type.
Collection<TypeConverter>	getTypeConvertersForType(Class memberType) Accessor for the available type converters for the provided Java type.
Class	getTypeForSecondClassWrapper(String className) Accessor for a java type that the supplied class is a SCO wrapper for.
Class	getWrappedTypeBackedForType(String className) Accessor for the backing-store Second Class Wrapper class for the supplied class.
Class	getWrapperTypeForType(String className) Accessor for the SCO wrapper for the type
boolean	isDefaultEmbeddedType(Class c) Accessor for whether the type is by default embedded.
boolean	isDefaultFetchGroup(Class c) Accessor for whether the type is by default in the DFG.
boolean	isDefaultFetchGroupForCollection(Class c, Class genericType) Accessor for whether the generic collection type is by default in the DFG.
boolean	isDefaultPersistent(Class c) Accessor for whether the type is by default persistent.
boolean	isSecondClassMutableType(String className) Accessor for whether the type is SCO mutable.
boolean	isSecondClassWrapper(String className) Accessor for whether the type is a SCO wrapper itself.
boolean	isSupportedSecondClassType(String className) Accessor for whether a class is supported as being second class.
void	registerConverter(String name, TypeConverter converter, Class memberType, Class dbType, boolean autoApply, String autoApplyType) Register a TypeConverter with the TypeManager process for specific attribute/db types.
void	setDefaultTypeConverterForType(Class memberType, String converterName) Method providing the ability for a datastore plugin to override the default converter type for the specified java type.
Object	wrapAndReplaceSCOField(ObjectProvider ownerOP, int memberNumber, Object newValue, Object oldValue, boolean replaceFieldIfChanged) Method to create a new SCO wrapper for the specified field replacing the old value with the new value.

Method Detail

close

void close()

getSupportedSecondClassTypes

Set<String> getSupportedSecondClassTypes()

Accessor for the supported second-class Types. This may or may not be a complete list, just that it provides the principal ones.

Returns:

Set of supported types (fully qualified class names).

isSupportedSecondClassType

boolean isSupportedSecondClassType(String className)

Accessor for whether a class is supported as being second class.

Parameters:

className - The class name

Returns:

Whether the class is supported (to some degree)

filterOutSupportedSecondClassNames

String[] filterOutSupportedSecondClassNames(String[] inputClassNames)

Convenience method to filter out any supported classes from a list.

Parameters:

inputClassNames - Names of the classes

Returns:

Names of the classes (omitting supported types)

isDefaultPersistent

boolean isDefaultPersistent(Class c)

Accessor for whether the type is by default persistent. TODO Support use of apiAdapter.isMemberDefaultPersistent to get strict JDO/JPA behaviour.

Parameters:

c - The type

Returns:

Whether persistent

isDefaultFetchGroup

boolean isDefaultFetchGroup(Class c)

Accessor for whether the type is by default in the DFG.

Parameters:

c - The type

Returns:

Whether in the DFG

isDefaultFetchGroupForCollection

boolean isDefaultFetchGroupForCollection(Class c,
                                         Class genericType)

Accessor for whether the generic collection type is by default in the DFG.

Parameters:

c - The type

genericType - The element generic type

Returns:

Whether in the DFG

isDefaultEmbeddedType

boolean isDefaultEmbeddedType(Class c)

Accessor for whether the type is by default embedded.

Parameters:

c - The type

Returns:

Whether embedded

isSecondClassMutableType

boolean isSecondClassMutableType(String className)

Accessor for whether the type is SCO mutable.

Parameters:

className - The type

Returns:

Whether SCO mutable

getWrapperTypeForType

Class getWrapperTypeForType(String className)

Accessor for the SCO wrapper for the type

Parameters:

className - The type

Returns:

SCO wrapper

getWrappedTypeBackedForType

Class getWrappedTypeBackedForType(String className)

Accessor for the backing-store Second Class Wrapper class for the supplied class. A type will have a SCO wrapper if it is SCO supported and is mutable. If there is no backed wrapper provided returns the simple wrapper.

Parameters:

className - The class name

Returns:

The second class wrapper

wrapAndReplaceSCOField

Object wrapAndReplaceSCOField(ObjectProvider ownerOP,
                              int memberNumber,
                              Object newValue,
                              Object oldValue,
                              boolean replaceFieldIfChanged)

Method to create a new SCO wrapper for the specified field replacing the old value with the new value. If the member value is a SCO already will just return the (new) value.

Parameters:

ownerOP - The ObjectProvider of the owner object

memberNumber - The member number in the owner

newValue - The value to initialise the wrapper with (if any) for this member

oldValue - The previous value that we are replacing with this value

replaceFieldIfChanged - Whether to replace the member in the object if wrapping the value

Returns:

The wrapper (or original value if not wrappable)

createSCOInstance

SCO createSCOInstance(ObjectProvider ownerOP,
                      AbstractMemberMetaData mmd,
                      Class instantiatedType,
                      Object value,
                      boolean replaceField)

Method to create a new SCO wrapper for the specified member. The SCO wrapper will be appropriate for the passed value (which represents the instantiated type of the field) unless it is null when the wrapper will be appropriate for the declared type of the field. While the "instantiated type" and the type of "value" should be the same when value is non-null, there are situations where we need to create a List based collection yet have no value so pass in the declaredType as Collection, instantiatedType as ArrayList, and value as null.

Parameters:

ownerOP - ObjectProvider managing the instance

mmd - Metadata for the member in question

instantiatedType - The instantiated type

value - The value to wrap

replaceField - Whether to replace the field in the owner object

Returns:

The SCO wrapper

isSecondClassWrapper

boolean isSecondClassWrapper(String className)

Accessor for whether the type is a SCO wrapper itself.

Parameters:

className - The type

Returns:

Whether is SCO wrapper

getTypeForSecondClassWrapper

Class getTypeForSecondClassWrapper(String className)

Accessor for a java type that the supplied class is a SCO wrapper for. If the supplied class is not a SCO wrapper for anything then returns null.

Parameters:

className - Name of the class

Returns:

The java class that this is a wrapper for (or null)

getContainerHandler

<H extends ContainerHandler> H getContainerHandler(Class containerClass)

Obtains the registered ContainerHandler for the given containerClass. ContainerHandler are specified via the plugin mechanism using the container-handler attribute of the java-type element.

Type Parameters:

H - Handler type

Parameters:

containerClass - The class of the container.

Returns:

The respective ContainerHandler if registered or null if no ContainerHandler is found for the containerClass.

getContainerAdapter

ContainerAdapter getContainerAdapter(Object container)

Convenience method to obtain the ContainerAdapter using the container object instance

Parameters:

container - The container instance

Returns:

The ContainerAdapter for the respective container or null if it's not a supported container

getTypeConverterForName

TypeConverter getTypeConverterForName(String converterName)

Accessor for the type converter with the provided name. This is used when the user has specified metadata for a field to use a particular named converter.

Parameters:

converterName - Name of the converter

Returns:

The converter

registerConverter

void registerConverter(String name,
                       TypeConverter converter,
                       Class memberType,
                       Class dbType,
                       boolean autoApply,
                       String autoApplyType)

Register a TypeConverter with the TypeManager process for specific attribute/db types. TypeConverters are registered either from the contents of "plugin.xml" (i.e the builtin types) where the name is of the form "dn.*", or from user-registered metadata (e.g JPA Annotations) where the name is the class name of the converter or a user supplied name.

Parameters:

name - The name to register the converter under

converter - The converter

memberType - Type of the java member

dbType - Type of the database column

autoApply - Whether this should be used as an auto-apply converter

autoApplyType - Java type to auto apply this for

getAutoApplyTypeConverterForType

TypeConverter getAutoApplyTypeConverterForType(Class memberType)

Method to return a TypeConverter that should be applied by default for the specified java (member) type. Will return null if the java type has no autoApply type defined for it (the default).

Parameters:

memberType - The java (member) type

Returns:

The converter to use by default

getDefaultTypeConverterForType

TypeConverter getDefaultTypeConverterForType(Class memberType)

Accessor for the default type converter for the provided Java type.

Parameters:

memberType - Java type for the member

Returns:

The default converter (if any)

setDefaultTypeConverterForType

void setDefaultTypeConverterForType(Class memberType,
                                    String converterName)

Method providing the ability for a datastore plugin to override the default converter type for the specified java type.

Parameters:

memberType - Member type

converterName - The converter to use by default. This is assumed to exist.

getTypeConverterForType

TypeConverter getTypeConverterForType(Class memberType,
                                      Class datastoreType)

Accessor for the type converter for the provided Java type and its datastore type.

Parameters:

memberType - Java type for the member

datastoreType - Java type for the datastore

Returns:

The converter (if any)

getTypeConvertersForType

Collection<TypeConverter> getTypeConvertersForType(Class memberType)

Accessor for the available type converters for the provided Java type.

Parameters:

memberType - The java type

Returns:

The available Type Converters

getDatastoreTypeForTypeConverter

Class getDatastoreTypeForTypeConverter(TypeConverter conv,
                                       Class memberType)

Method to return the datastore type for the specified TypeConverter.

Parameters:

conv - The converter

memberType - The member type

Returns:

The datastore type

getMemberTypeForTypeConverter

Class getMemberTypeForTypeConverter(TypeConverter conv,
                                    Class datastoreType)

Method to return the member type for the specified TypeConverter.

Parameters:

conv - The converter

datastoreType - The datastore type for this converter

Returns:

The member type