org.datanucleus.metadata

Class MetaData

java.lang.Object

org.datanucleus.metadata.MetaData

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

AbstractClassMetaData, AbstractConstraintMetaData, AbstractElementMetaData, AbstractMemberMetaData, ColumnMetaData, ContainerMetaData, DiscriminatorMetaData, EmbeddedMetaData, EventListenerMetaData, FetchGroupMemberMetaData, FetchGroupMetaData, FetchPlanMetaData, FileMetaData, IdentityMetaData, ImplementsMetaData, InheritanceMetaData, JoinMetaData, OrderMetaData, PackageMetaData, PersistenceFileMetaData, PersistenceUnitMetaData, PrimaryKeyMetaData, QueryMetaData, QueryResultMetaData, SequenceMetaData, StoredProcQueryMetaData, StoredProcQueryParameterMetaData, TableGeneratorMetaData, VersionMetaData

public class MetaData
extends Object
implements Serializable

Base class for all MetaData.

MetaData Lifecycle

The states represent the lifecycle of a MetaData object. The lifecycle goes as follows :

1. MetaData object is created (values passed in from a parsed file, or manually generated)
2. MetaData object is populated (maybe pass in a class that it represents, creating any additional information that wasn't in the initial data).
3. MetaData object is initialised (any internal arrays are set up, and additions of data is blocked from this point).
4. MetaData object is added to with runtime information like actual column names and types in use.

MetaData Extensability

All MetaData elements are extensible with extensions for a "vendor-name". Extensions take the form of a key and a value.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected Collection<ExtensionMetaData>	extensions List of extensions for this MetaData element.
protected static Localiser	LOCALISER
static int	METADATA_CREATED_STATE State representing the start state of MetaData, representing the initial values passed in.
static int	METADATA_INITIALISED_STATE State reflecting that MetaData object has been initialised with any internal info required.
static int	METADATA_POPULATED_STATE State reflecting that MetaData has been populated with real class definition adding any defaulted info.
static int	METADATA_USED_STATE State reflecting that MetaData object has been modified with usage information (e.g defaulted column names).
protected int	metaDataState State of the MetaData.
protected MetaData	parent Parent MetaData object, allowing hierarchical MetaData structure.
static String	VENDOR_NAME Vendor name (DataNucleus) used for extensions.
static String	VENDOR_NAME_OLD Vendor name (JPOX) used for extensions.

Constructor Summary

Constructors

Constructor and Description
MetaData()
MetaData(MetaData parent) Constructor.
MetaData(MetaData parent, MetaData copy) Copy constructor.

Method Summary

Methods

Modifier and Type	Method and Description
MetaData	addExtension(String key, String value)
MetaData	addExtension(String vendor, String key, String value)
void	assertIfInitialised()
ExtensionMetaData[]	getExtensions()
int	getNoOfExtensions()
MetaData	getParent()
String	getValueForExtension(String key) Accessor for the value of a particular extension.
String[]	getValuesForExtension(String key) Accessor for the value of a particular extension, but splitting it into separate parts.
boolean	hasExtension(String key)
void	initialise(ClassLoaderResolver clr, MetaDataManager mmgr)
boolean	isInitialised()
boolean	isPopulated()
boolean	isUsed()
ExtensionMetaData	newExtensionMetaData(String vendor, String key, String value) Method to create a new ExtensionMetaData, add it, and return it.
MetaData	removeExtension(String key)
void	setParent(MetaData md)
String	toString() Accessor for a string representation of the object.
String	toString(String prefix, String indent) Returns a string representation of the object.

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER

protected static final Localiser LOCALISER

METADATA_CREATED_STATE

public static final int METADATA_CREATED_STATE

State representing the start state of MetaData, representing the initial values passed in.

See Also:

Constant Field Values

METADATA_POPULATED_STATE

public static final int METADATA_POPULATED_STATE

State reflecting that MetaData has been populated with real class definition adding any defaulted info.

See Also:

Constant Field Values

METADATA_INITIALISED_STATE

public static final int METADATA_INITIALISED_STATE

State reflecting that MetaData object has been initialised with any internal info required.

See Also:

Constant Field Values

METADATA_USED_STATE

public static final int METADATA_USED_STATE

State reflecting that MetaData object has been modified with usage information (e.g defaulted column names).

See Also:

Constant Field Values

metaDataState

protected int metaDataState

State of the MetaData.

parent

protected MetaData parent

Parent MetaData object, allowing hierarchical MetaData structure.

VENDOR_NAME

public static final String VENDOR_NAME

Vendor name (DataNucleus) used for extensions.

See Also:

Constant Field Values

VENDOR_NAME_OLD

public static final String VENDOR_NAME_OLD

Vendor name (JPOX) used for extensions.

See Also:

Constant Field Values

extensions

protected Collection<ExtensionMetaData> extensions

List of extensions for this MetaData element.

Constructor Detail

MetaData

public MetaData()

MetaData

public MetaData(MetaData parent)

Constructor. Taking the parent MetaData object (if any).

Parameters:

parent - The parent MetaData object.

MetaData

public MetaData(MetaData parent,
        MetaData copy)

Copy constructor. Taking the parent MetaData object, and an object to copy from.

Parameters:

parent - The parent MetaData object.

copy - The metadata to copy from

Method Detail

initialise

public void initialise(ClassLoaderResolver clr,
              MetaDataManager mmgr)

setParent

public void setParent(MetaData md)

addExtension

public MetaData addExtension(String vendor,
                    String key,
                    String value)

addExtension

public MetaData addExtension(String key,
                    String value)

newExtensionMetaData

public ExtensionMetaData newExtensionMetaData(String vendor,
                                     String key,
                                     String value)

Method to create a new ExtensionMetaData, add it, and return it.

Parameters:

vendor - The vendor name

key - Key of the extension

value - Value

Returns:

The extension

removeExtension

public MetaData removeExtension(String key)

getParent

public MetaData getParent()

isPopulated

public boolean isPopulated()

isInitialised

public boolean isInitialised()

isUsed

public boolean isUsed()

getNoOfExtensions

public int getNoOfExtensions()

assertIfInitialised

public void assertIfInitialised()

getExtensions

public ExtensionMetaData[] getExtensions()

hasExtension

public boolean hasExtension(String key)

getValueForExtension

public String getValueForExtension(String key)

Accessor for the value of a particular extension.

Parameters:

key - The key of the extension

Returns:

The value of the extension (null if not existing)

getValuesForExtension

public String[] getValuesForExtension(String key)

Accessor for the value of a particular extension, but splitting it into separate parts. This is for extension tags that have a value as comma separated.

Parameters:

key - The key of the extension

Returns:

The value(s) of the extension (null if not existing)

toString

public String toString()

Accessor for a string representation of the object.

Overrides:

toString in class Object

Returns:

a string representation of the object.

toString

public String toString(String prefix,
              String indent)

Returns a string representation of the object.

Parameters:

prefix - prefix string

indent - indent string

Returns:

a string representation of the object.