| org.odmg.Database
| Database | | public interface Database (Code) | | The interface for interacting with an ODMG database.
Databases must be opened before starting any transactions that use the database
and closed after ending these transactions.
A database application generally begins processing by accessing one or more
critical objects and proceeding from there. These objects are root objects,
because they lead to interconnected webs of other objects.
The ability to name an object (using method bind) and
retrieve it later by that name (using method lookup facilitates
this start-up capability. A name is not explicitly defined as an attribute of
an object. Naming an object also makes it persistent.
There is a single flat name scope per database; thus all names in a particular
database are unique.
author:
David Jordan (as Java Editor of the Object Data Management Group)
version:
ODMG 3.0 |
| Field Summary | |
| final public static int | NOT_OPEN
The database is not open. | | final public static int | OPEN_EXCLUSIVE
The database is open for exclusive access. | | final public static int | OPEN_READ_ONLY
The database is opened for read-only access. | | final public static int | OPEN_READ_WRITE
The database is opened for reading and writing. |
| Method Summary | |
| public void | bind(Object object, String name)
Associate a name with an object and make it persistent. | | public void | close()
Close the database. | | public void | deletePersistent(Object object)
Deletes an object from the database. | | public Object | lookup(String name)
Lookup an object via its name.
Parameters:
name - The name of an object. | | public void | makePersistent(Object object)
Make a transient object durable in the database. | | public void | open(String name, int accessMode)
Open the named database with the specified access mode. | | public void | unbind(String name)
|
| NOT_OPEN | | final public static int NOT_OPEN(Code) | | The database is not open.
|
| OPEN_EXCLUSIVE | | final public static int OPEN_EXCLUSIVE(Code) | | The database is open for exclusive access.
|
| OPEN_READ_ONLY | | final public static int OPEN_READ_ONLY(Code) | | The database is opened for read-only access.
|
| OPEN_READ_WRITE | | final public static int OPEN_READ_WRITE(Code) | | The database is opened for reading and writing.
|
| bind | | public void bind(Object object, String name) throws ObjectNameNotUniqueException(Code) | | Associate a name with an object and make it persistent.
An object instance may be bound to more than one name.
Binding a previously transient object to a name makes that object persistent.
Parameters:
object - The object to be named.
Parameters:
name - The name to be given to the object.
exception:
org.odmg.ObjectNameNotUniqueException - If an attempt is made to bind a name to an object and that name is already boundto an object. |
| close | | public void close() throws ODMGException(Code) | | Close the database.
After you have closed a database, further attempts to access objects in the
database will cause the exception DatabaseClosedException to be thrown.
Some implementations may throw additional exceptions that are also derived
from ODMGException.
exception:
ODMGException - Unable to close the database. |
| deletePersistent | | public void deletePersistent(Object object)(Code) | | Deletes an object from the database.
It must be executed in the context of an open transaction.
If the object is not persistent, then ObjectNotPersistent is thrown.
If the transaction in which this method is executed commits,
then the object is removed from the database.
If the transaction aborts,
then the deletePersistent operation is considered not to have been executed,
and the target object is again in the database.
Parameters:
object - The object to delete. |
| makePersistent | | public void makePersistent(Object object)(Code) | | Make a transient object durable in the database.
It must be executed in the context of an open transaction.
If the transaction in which this method is executed commits,
then the object is made durable.
If the transaction aborts,
then the makePersistent operation is considered not to have been executed,
and the target object is again transient.
ClassNotPersistenceCapableException is thrown if the implementation cannot make
the object persistent because of the type of the object.
Parameters:
object - The object to make persistent. |
| open | | public void open(String name, int accessMode) throws ODMGException(Code) | | Open the named database with the specified access mode.
Attempts to open a database when it has already been opened will result in
the throwing of the exception DatabaseOpenException.
A DatabaseNotFoundException is thrown if the database does not exist.
Some implementations may throw additional exceptions that are also derived from
ODMGException.
Parameters:
name - The name of the database.
Parameters:
accessMode - The access mode, which should be one of the static fields:OPEN_READ_ONLY, OPEN_READ_WRITE,or OPEN_EXCLUSIVE.
exception:
ODMGException - The database could not be opened. |
|
|