org.datanucleus.metadata
Class FieldMetaData

java.lang.Object
  org.datanucleus.metadata.MetaData
      org.datanucleus.metadata.AbstractMemberMetaData
          org.datanucleus.metadata.FieldMetaData

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable, ColumnMetaDataContainer

public class FieldMetaData
extends AbstractMemberMetaData

Representation of the Meta-Data for a field of a class.

Lifecycle state

An object of this type has 2 lifecycle states. The first is the raw constructed object which represents pure MetaData (maybe from a MetaData file). The second is a "populated" object which represents MetaData for a Field of a class with the metadata aligned to be appropriate for that Field.

Containers

Each field can represent a container. The container can be an array, a Collection or a Map. The field type must be of the correct type to represent these.

JPOX Management

Each field can be managed by JPOX or not. The class provides a method for identifying if a field is managed by JPOX (isJdoField()). If a field is managed by JPOX, it will have a field "id" (within its class). In a class the field "id" will start at 0 (for the first field, in alphabetical order).

MetaData Element

The MetaData element represented here is as follows

 
 <!ELEMENT field (extension*, (collection|map|array|(column*))?, join?, element?, 
      key?, value?, fetch-group*, order?, embedded?, index?, unique?, foreign-key?,
      delete-action?, extension*)?>
 <!ATTLIST field name CDATA #REQUIRED>
 <!ATTLIST field persistence-modifier (persistent|transactional|none)
      #IMPLIED>
 <!ATTLIST field table CDATA #IMPLIED>
 <!ATTLIST field null-value (exception|default|none) 'none'>
 <!ATTLIST field default-fetch-group (true|false) #IMPLIED>
 <!ATTLIST field embedded (true|false) #IMPLIED>
 <!ATTLIST field serialized (true|false) #IMPLIED>
 <!ATTLIST field dependent (true|false) #IMPLIED>
 <!ATTLIST field indexed (true|false|unique) #IMPLIED>
 <!ATTLIST field unique (true|false) #IMPLIED>
 <!ATTLIST field load-fetch-group CDATA #IMPLIED>
 <!ATTLIST field recursion-depth CDATA #IMPLIED>
 <!ATTLIST field primary-key (true|false) 'false'>
 <!ATTLIST field mapped-by CDATA #IMPLIED>
 <!ATTLIST field value-strategy CDATA #IMPLIED>
 <!ATTLIST field delete-action (restrict|cascade|null|default|none) #IMPLIED>
 <!ATTLIST field sequence CDATA #IMPLIED>
 <!ATTLIST field field-type CDATA #IMPLIED>
 

Since:

1.1

Version:

$Revision: 1.83 $

See Also:

Serialized Form

Field Summary

Fields inherited from class org.datanucleus.metadata.AbstractMemberMetaData

cacheable, cascadeDelete, cascadePersist, cascadeRefresh, cascadeUpdate, catalog, className, column, columnMetaData, columns, container, DEFAULT_RECURSION_DEPTH, defaultFetchGroup, dependent, elementMetaData, embedded, embeddedMetaData, fieldId, fieldTypes, foreignKeyMetaData, fullFieldName, indexed, indexMetaData, jdoFieldFlag, joinMetaData, keyMetaData, loadFetchGroup, mappedBy, modifiers, name, nullValue, ordered, orderMetaData, persistenceModifier, primaryKey, recursionDepth, relatedMemberMetaData, relationType, schema, sequence, serialized, storeInLob, table, targetClassName, type, UNDEFINED_RECURSION_DEPTH, uniqueConstraint, uniqueMetaData, valueGeneratorName, valueMetaData, valueStrategy

Fields inherited from class org.datanucleus.metadata.MetaData

extensions, LOCALISER, METADATA_CREATED_STATE, METADATA_INITIALISED_STATE, METADATA_POPULATED_STATE, METADATA_USED_STATE, metaDataState, parent, VENDOR_NAME, VENDOR_NAME_OLD

Constructor Summary

FieldMetaData(MetaData parent, AbstractMemberMetaData fmd)
Convenience constructor to copy the specification from the passed field.

FieldMetaData(MetaData parent, java.lang.String name)
Convenience constructor taking defaults

FieldMetaData(MetaData parent, java.lang.String name, java.lang.String pk, java.lang.String modifier, java.lang.String defaultFetchGroup, java.lang.String nullValue, java.lang.String embedded, java.lang.String serialized, java.lang.String dependent, java.lang.String mappedBy, java.lang.String column, java.lang.String table, java.lang.String catalog, java.lang.String schema, java.lang.String deleteAction, java.lang.String indexed, java.lang.String unique, java.lang.String recursionDepth, java.lang.String loadFetchGroup, java.lang.String valueStrategy, java.lang.String sequence, java.lang.String fieldType)
Constructor.

Method Summary

int	compareTo(java.lang.Object o) Comparator method.
boolean	isProperty() Whether this uses getter/setter accessors (Property) or used field based access (Field)
java.lang.String	toString(java.lang.String prefix, java.lang.String indent) Returns a string representation of the object using a prefix This can be used as part of a facility to output a MetaData file.

Methods inherited from class org.datanucleus.metadata.AbstractMemberMetaData

addColumn, calcIsSecondClassMutable, fieldBelongsToClass, getAbsoluteFieldNumber, getAbstractClassMetaData, getArray, getCatalog, getClassName, getClassName, getCollection, getColumn, getColumnMetaData, getContainer, getDefaultFieldPersistenceModifier, getElementMetaData, getEmbeddedMetaData, getFieldId, getFieldTypes, getForeignKeyMetaData, getFullFieldName, getIndexMetaData, getJdoFieldFlag, getJoinMetaData, getKeyMetaData, getLoadFetchGroup, getMap, getMappedBy, getMetaDataManager, getName, getNullValue, getOrderMetaData, getOverallParentClassMetaData, getPersistenceModifier, getRecursionDepth, getRelatedMemberMetaData, getRelatedMemberMetaDataForObject, getRelationType, getSchema, getSequence, getTable, getType, getTypeName, getUniqueMetaData, getValueGeneratorName, getValueMetaData, getValueStrategy, hasArray, hasCollection, hasContainer, hasMap, initialise, isAbstract, isCacheable, isCascadeDelete, isCascadePersist, isCascadeRefresh, isCascadeUpdate, isDefaultFetchGroup, isDependent, isEmbedded, isFieldArrayTypePersistable, isFieldTypePersistable, isFinal, isJdoField, isPersistentInterface, isPrimaryKey, isPrivate, isProtected, isPublic, isRelationOwner, isSerialized, isStatic, isTransient, populate, setCacheable, setCascadeDelete, setCascadePersist, setCascadeRefresh, setCascadeUpdate, setCatalog, setContainer, setDefaultFetchGroup, setDependent, setElementMetaData, setEmbeddedMetaData, setForeignKeyMetaData, setIndexMetaData, setJoinMetaData, setKeyMetaData, setLoadFetchGroup, setMappedBy, setNotPersistent, setOrdered, setOrderMetaData, setPrimaryKey, setRelation, setSchema, setSequence, setSerialised, setStoreInLob, setTable, setTargetClassName, setTransactional, setUniqueMetaData, setValueGeneratorName, setValueMetaData, setValueStrategy

Methods inherited from class org.datanucleus.metadata.MetaData

addExtension, addExtension, getExtensions, getNoOfExtensions, getParent, getValueForExtension, getValuesForExtension, hasExtension, isInitialised, isPopulated, isUsed, removeExtension, setInitialised, setParent, setPopulated, setUsed, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

FieldMetaData

public FieldMetaData(MetaData parent,
                     java.lang.String name)

Convenience constructor taking defaults

Parameters:

parent - Parent component

name - Name of the field

FieldMetaData

public FieldMetaData(MetaData parent,
                     AbstractMemberMetaData fmd)

Convenience constructor to copy the specification from the passed field. This is used when we have an overriding field and we make a copy of the baseline field as a starting point.

Parameters:

parent - The parent

fmd - The field to copy

FieldMetaData

public FieldMetaData(MetaData parent,
                     java.lang.String name,
                     java.lang.String pk,
                     java.lang.String modifier,
                     java.lang.String defaultFetchGroup,
                     java.lang.String nullValue,
                     java.lang.String embedded,
                     java.lang.String serialized,
                     java.lang.String dependent,
                     java.lang.String mappedBy,
                     java.lang.String column,
                     java.lang.String table,
                     java.lang.String catalog,
                     java.lang.String schema,
                     java.lang.String deleteAction,
                     java.lang.String indexed,
                     java.lang.String unique,
                     java.lang.String recursionDepth,
                     java.lang.String loadFetchGroup,
                     java.lang.String valueStrategy,
                     java.lang.String sequence,
                     java.lang.String fieldType)

Constructor. Saves the MetaData with the specified values. The object is then in an "unpopulated" state. It can become "populated" by calling the populate() method which compares it against the field it is to represent and updates any unset attributes and flags up any errors.

Parameters:

parent - parent MetaData instance

name - field name

pk - attribute primary-key value

modifier - attribute persistence-modifier value

defaultFetchGroup - attribute default-fetch-group value

nullValue - attribute null-value value

embedded - attribute embedded value

serialized - attribute serialized value

dependent - attribute dependent value

mappedBy - attribute mapped-by value

column - attribute column value

table - attribute table value

catalog - attribute catalog value

schema - attribute schema value

deleteAction - attribute delete-action value

indexed - Whether this is indexed

unique - Apply a unique constraint

recursionDepth - The depth of fetch to use when recursing

loadFetchGroup - Name of the additional fetch group to use when loading

valueStrategy - attribute value-strategy value

sequence - attribute sequence value

fieldType - Implementation type(s) for field.

Method Detail

isProperty

public boolean isProperty()

Whether this uses getter/setter accessors (Property) or used field based access (Field)

Specified by:

isProperty in class AbstractMemberMetaData

Returns:

true if this is a property

toString

public java.lang.String toString(java.lang.String prefix,
                                 java.lang.String indent)

Returns a string representation of the object using a prefix This can be used as part of a facility to output a MetaData file.

Overrides:

toString in class AbstractMemberMetaData

Parameters:

prefix - prefix string

indent - indent string

Returns:

a string representation of the object.

compareTo

public int compareTo(java.lang.Object o)

Comparator method. This allows the ClassMetaData to search for a FieldMetaData with a particular name.

Specified by:

compareTo in interface java.lang.Comparable

Overrides:

compareTo in class AbstractMemberMetaData

Parameters:

o - The object to compare against

Returns:

The comparison result