oracle.jbo.server
Interface Entity

All Superinterfaces:

AttributeList, java.util.EventListener, Row, TransactionListener, oracle.jbo.server.TransactionManager, TransactionPostListener, ValidationListener, ValidationManager, XMLInterface

All Known Implementing Classes:

EntityImpl

public interface Entity

extends Row, ValidationListener, ValidationManager, oracle.jbo.server.TransactionManager, TransactionListener, TransactionPostListener

This interface is for BC4J Entity Objects. Entity Object is responsible for managing data (attribute) values, updates to them, and interacting with the persistence service, e.g., RDBMS.

An Entity Object provides an object-oriented representation of the data it caches from a persistence service (most commonly, RDBMS). For RDBMS, each database row is presented as individual Entity Object, in which attributes typically correspond to columns in the database table.

An Entity Object goes through different states based on client's actions. An Entity Object keeps two states: post-state and entity-state.

States are set to one of STATUS_INITIALIZED, STATUS_NEW, STATUS_UNMODIFIED, STATUS_MODIFIED, STATUS_DELETED, or STATUS_DEAD by various row manipulation operations, e.g., create, update, delete, and rollback. These operations can change the post-state and the entity-state.

The post-state indicates the state of the Entity Object relative to the last data posted row in the database. The entity-state indicates the state of the Entity Object relative to the transaction itself. See STATUS_... constants for further discussions.

An Entity Object is owned by its container. A Entity Object container may be the Transaction object or the master Entity Object. The latter is the case if this Entity Object is a child (detail) Entity in a composition association. In this case, the master Entity Object owns this Entity Object, and the master Entity Object is said to be the container. The Entity Object container plays the role of a TransactionManager and ValidationManager for its children (containees).

When an Entity Object attribute values are modified, the container is notified. The container registers the modified Entity Object in its transaction-post-listener list and validation-listener list. The transaction-post-listener list is a list of objects that need to be posted to the underlying persistence service. The validation-listener list is a list of objects that need to be validated before they are written (posted) to the persistence service.

Since:

JDeveloper 3.0

Field Summary

static byte	STATUS_DEAD Indicates that the Entity Object is a new row that has been discarded.
static byte	STATUS_DELETED Indicates that the Entity Object's row has been deleted.
static byte	STATUS_MODIFIED Indicates that the Entity Object's row is changed.
static byte	STATUS_UNMODIFIED Indicates that the Entity Object's row is unchanged or has been updated.

Fields inherited from interface oracle.jbo.Row

REFRESH_CONTAINEES, REFRESH_FORGET_NEW_ROWS, REFRESH_REMOVE_NEW_ROWS, REFRESH_UNDO_CHANGES, REFRESH_WITH_DB_FORGET_CHANGES, REFRESH_WITH_DB_ONLY_IF_UNCHANGED, STATUS_INITIALIZED, STATUS_NEW

Fields inherited from interface oracle.jbo.XMLInterface

XML_IGNORE_DEPTH_COUNT, XML_OPT_ALL_ROWS, XML_OPT_ASSOC_CONSISTENT, XML_OPT_CHANGES_ONLY, XML_OPT_LIMIT_RANGE

Method Summary

void	addTransactionPostListener(TransactionPostListener listener)
void	addTransactionPostListenerNoCheck(TransactionPostListener listener)
byte	getEntityState() Gets this Entity Object's current entity-state.
byte	getPostState() Gets this Entity Object's current post-state.
Key	getPrimaryKey() Returns the primay key for this Entity Object's row.
boolean	isLocked() Gets the status of the Entity Object's lock.
boolean	isValid() Returns the state of this Entity Object's validity flag.
void	removeTransactionPostListener(TransactionPostListener listener)
void	revert() Reverts this Entity Object's row to the database's values.

Methods inherited from interface oracle.jbo.Row

getKey, getStructureDef, isAttributeUpdateable, lock, refresh, remove, removeAndRetain, removeFromCollection, setNewRowState, validate

Methods inherited from interface oracle.jbo.AttributeList

getAttribute, getAttribute, getAttributeCount, getAttributeIndexOf, getAttributeNames, getAttributeValues, setAttribute, setAttribute

Methods inherited from interface oracle.jbo.XMLInterface

readXML, readXML, writeXML, writeXML, writeXML, writeXML

Methods inherited from interface oracle.jbo.server.ValidationListener

validate

Methods inherited from interface oracle.jbo.server.ValidationManager

addToValidationListeners, validate

Methods inherited from interface oracle.jbo.server.TransactionListener

afterCommit, afterRemove, afterRollback, beforeCommit, beforeRollback, isTransientTransactionListener

Methods inherited from interface oracle.jbo.server.TransactionPostListener

getTransPostHandle, isPostedToDB, isTransientTransactionPostListener, postChanges, setPostedToDB, setTransPostHandle

Field Detail

STATUS_UNMODIFIED

public static final byte STATUS_UNMODIFIED

Indicates that the Entity Object's row is unchanged or has been updated.

See Also:

Constant Field Values

STATUS_MODIFIED

public static final byte STATUS_MODIFIED

Indicates that the Entity Object's row is changed.

See Also:

Constant Field Values

STATUS_DELETED

public static final byte STATUS_DELETED

Indicates that the Entity Object's row has been deleted.

See Also:

Constant Field Values

STATUS_DEAD

public static final byte STATUS_DEAD

Indicates that the Entity Object is a new row that has been discarded.

See Also:

Constant Field Values

Method Detail

isValid

public boolean isValid()

Returns the state of this Entity Object's validity flag. This predecate does not perform a validity test.

An Entity Object is marked valid if it has been validated and not subsequently modified or set invalid.

Specified by:

isValid in interface ValidationListener

Returns:

true if this Entity Object has been validated.

getPrimaryKey

public Key getPrimaryKey()

Returns the primay key for this Entity Object's row. For example, if you are comparing two Entity Objects, you can compare the keys instead of comparing the Entities.

Typically, this method should not be overridden.

Returns:

the primary key.

isLocked

public boolean isLocked()

Gets the status of the Entity Object's lock.

An Entity Object is locked if its corresponding database row is locked. This method should not be overridden.

Returns:

true if this Entity Object is locked.

getEntityState

public byte getEntityState()

Gets this Entity Object's current entity-state. An Entity Object's state can be one of:

• STATUS_UNMODIFIED - if this Entity Object originated in the database and is unmodified, or if modifications have been committed to the database.
• STATUS_MODIFIED - if this Entity Object originated in the database, and has been modified in the current transaction.
• STATUS_NEW - if this Entity Object is new in the current transaction.
• STATUS_DELETED - if this Entity Object has been deleted in the current transaction.
• STATUS_DEAD - if this Entity Object is new in the current transaction and has been deleted.

Returns:

one of STATUS_UNMODIFIED, STATUS_MODIFIED, STATUS_NEW, STATUS_DELETED, or STATUS_DEAD

getPostState

public byte getPostState()

Gets this Entity Object's current post-state. The current post state can be one of:

• STATUS_UNMODIFIED - if this Entity Object has been queried from the database and is unchanged, or if it has been posted to the database.
• STATUS_MODIFIED - if this Entity Object has been queried from the database and has changed.
• STATUS_NEW - if this Entity Object is new and not yet posted to the database.
• STATUS_DELETED - if this Entity Object has been marked for deletion.
• STATUS_DEAD - if this Entity Object is new, but has been deleted.

Returns:

one of STATUS_UNMODIFIED, STATUS_MODIFIED, STATUS_NEW, STATUS_DELETED, or STATUS_DEAD

revert

public void revert()

Reverts this Entity Object's row to the database's values.

Calling this method will either reset the attribute values to their database values or revert them to their default values. If the Entity Object is posted, all the attributes revert to the to unread state, so that a subsequent EntityImpl.getAttribute(int index) call will refresh all attributes from the database.

See Also:

EntityImpl.getAttribute(int index)

addTransactionPostListener

public void addTransactionPostListener(TransactionPostListener listener)

addTransactionPostListenerNoCheck

public void addTransactionPostListenerNoCheck(TransactionPostListener listener)

removeTransactionPostListener

public void removeTransactionPostListener(TransactionPostListener listener)