Implementation of the JDO engine used for obtaining database
connection. A JDO object is constructed with the name of a database
and other properties, and
getDatabase()
is used to obtain a
new database connection. Any number of database connections can be
obtained from the same JDO object.
The database configuration can be loaded using one of the
loadConfiguration
method. Alternatively,
setConfiguration(String)
can be used to specify the URL of a database configuration file.
The configuration will loaded only once.
For example:
// Load the database configuration
JDO.loadConfiguration( "database.xml" );
. . .
JDO jdo;
Database db;
// Construct a new JDO for the database 'mydb'
jdo = new JDO( "mydb" );
// Open a connection to the database
db = jdo.getDatabase();
Or,
JDO jdo;
Database db;
// Construct a new JDO and specify the configuration file
jdo = new JDO( "mydb" );
jdo.setConfiguration( "database.xml" );
// Open a connection to the database
db = jdo.getDatabase();
getClassLoader
public ClassLoader getClassLoader()
Returns the application classloader.
getConfiguration
public String getConfiguration()
Return the URL of the database configuration file.
The standard name for this property is
configuration.
- The URL of the database configuration file
getDatabaseName
public String getDatabaseName()
Returns the name of this database.
The standard name for this property is
databaseName.
- The name of this database
getDatabasePooling
public boolean getDatabasePooling()
Indicates if jdo Database pooling is enable or not.
Experimental maybe removed in the further release
getDescription
public String getDescription()
Returns the description of this database.
The standard name for this property is
description.
- getDescription in interface DataObjects
- The description of this database
getEntityResolver
public EntityResolver getEntityResolver()
Returns the entity resolver.
getLockTimeout
public int getLockTimeout()
Returns the lock timeout for this database.
The standard name for this property is
lockTimeout.
- The lock timeout, specified in seconds
getLogInterceptor
public LogInterceptor getLogInterceptor()
Returns the log interceptor for this database source.
- The log interceptor, null if disabled
getObjectInstance
public Object getObjectInstance(Object refObj,
Name name,
Context nameCtx,
Hashtable env)
throws NamingException
getReference
public Reference getReference()
getTransactionManager
public String getTransactionManager()
Returns the JNDI name of the transaction manager.
isAutoStore
public boolean isAutoStore()
loadConfiguration
public static void loadConfiguration(InputSource source,
EntityResolver resolver,
ClassLoader loader)
throws MappingException
Load database configuration from the specified input source.
source must point to a JDO configuration file describing
the database* name, connection factory and mappings.
resolver can be used to resolve cached entities, e.g.
for external mapping documents. loader is optional, if
null the default class loader is used.
source
- The JDO configuration fileloader
- The class loader to use, null for the default
loadConfiguration
public static void loadConfiguration(String url)
throws MappingException
Load database configuration from the specified URL. url
must point to a JDO configuration file describing the database
name, connection factory and mappings.
url
- The JDO configuration file
loadConfiguration
public static void loadConfiguration(String url,
ClassLoader loader)
throws MappingException
Load database configuration from the specified URL. url
must point to a JDO configuration file describing the database
name, connection factory and mappings. loader is
optional, if null the default class loader is used.
url
- The JDO configuration fileloader
- The class loader to use, null for the default
setAutoStore
public void setAutoStore(boolean autoStore)
setCallbackInterceptor
public void setCallbackInterceptor(CallbackInterceptor callback)
Overrides the default callback interceptor by a custom
interceptor for this database source.
The interceptor is a callback that notifies data objects
on persistent state events.
If callback interceptor is not overrided, events will be
sent to data object that implements the org.exolab.castor.jdo.Persistent
interface.
callback
- The callback interceptor, null if disabled
setClassLoader
public void setClassLoader(ClassLoader classLoader)
Sets the application class loader.
This method should be used with application servers that use multiple
class loaders. The default value is "null". It means that
application classes are loaded through
Class.forName(className)
.
Examples:
jdo.setClassLoader(getClass().getClassLoader());
jdo.setClassLoader(Thread.currentThread().getContextClassLoader());
setConfiguration
public void setConfiguration(String url)
Sets the URL of the database configuration file. If the URL is
specified, the first attempt to load a database of this type
will use the specified configuration file. If the URL is not
specified, use one of the
loadConfiguration
methods
instead.
The standard name for this property is
configuration.
url
- The URL of the database configuration file
setDatabaseName
public void setDatabaseName(String name)
Sets the name of this database. This attribute is required
in order to identify which database to open.
The standard name for this property is
databaseName.
name
- The name of this database
setDatabasePooling
public void setDatabasePooling(boolean pool)
Enable/disable jdo Database pooling. This option only affects
JDO if transactionManager is set and a transaction is associated
with the thread that call
getDatabase()
. If jdo Database pooling
is enabled, JDO will first search in the pool to see if there
is already a Database for the current transaction. If found, it
returns the database; if not, it create a new one, associates
it will the transaction and return the newly created Database.
This method should be called before the invocation of
getDatabase()
.
Experimental maybe removed in the future releases
pool
- true to enable database pooling
setDescription
public void setDescription(String description)
Sets the description of this database.
The standard name for this property is
description.
- setDescription in interface DataObjects
description
- The description of this database
setEntityResolver
public void setEntityResolver(EntityResolver entityResolver)
Sets the entity resolver.
The resolver can be used to resolve cached entities, e.g.
for external mapping documents.
Note, that you cannot create two Database instances that differ
only in a resolver.
setInstanceFactory
public void setInstanceFactory(InstanceFactory factory)
Overrides the default instance factory by a custom one
to be used by Castor to obtaining an instance of data
object when it is needed during loading.
If instance factory is not overrided, and if class loader
is not set, Class.forName( className ).newInstance() will
be used; if instance factory is not override, and class
loader is set, loader.loadClass( className ).newInstance()
will be used to create a new instance.
factory
- The instance factory, null to use the default
setLockTimeout
public void setLockTimeout(int seconds)
Sets the lock timeout for this database. Use zero for immediate
timeout, an infinite value for no timeout. The timeout is
specified in seconds.
The standard name for this property is
lockTimeout.
seconds
- The lock timeout, specified in seconds
setLogInterceptor
public void setLogInterceptor(LogInterceptor logInterceptor)
Sets the log interceptor for this database source.
The interceptor is a callback to to which all
logging and tracing messages are sent.
logInterceptor
- The log interceptor, null if disabled
setLogWriter
public void setLogWriter(PrintWriter logWriter)
Returns the log writer for this database source.
The log writer is a character output stream to which all
logging and tracing messages will be printed.
setTransactionManager
public void setTransactionManager(String tmName)
Sets the JNDI name of the transaction manager. If set, JDO will look
up this name through JNDI and if available register itself
for synchronization and take part in a distributed transaction.
The standard name for this property is
transactionManager.
tmName
- The JNDI name of the transaction manager