|
JavaTM 2 Platform Standard Ed. 5.0 |
|||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||
java.lang.Objectjavax.sql.rowset.spi.SyncFactory
public class SyncFactory
The Service Provider Interface (SPI) mechanism that generates SyncProvider
instances to be used by disconnected RowSet objects.
The SyncProvider instances in turn provide the
javax.sql.RowSetReader object the RowSet object
needs to populate itself with data and the
javax.sql.RowSetWriter object it needs to
propagate changes to its
data back to the underlying data source.
Because the methods in the SyncFactory class are all static,
there is only one SyncFactory object
per Java VM at any one time. This ensures that there is a single source from which a
RowSet implementation can obtain its SyncProvider
implementation.
SyncFactory class provides an internal registry of available
synchronization provider implementations (SyncProvider objects).
This registry may be queried to determine which
synchronization providers are available.
The following line of code gets an enumeration of the providers currently registered.
java.util.Enumeration e = SyncFactory.getRegisteredProviders();
All standard RowSet implementations must provide at least two providers:
CachedRowSet implementation
or an implementation derived from it
WebRowSet objects
SyncProvider
implemtations RIOptimisticProvider and RIXmlProvider,
which satisfy this requirement.
The SyncFactory class provides accessor methods to assist
applications in determining which synchronization providers are currently
registered with the SyncFactory.
Other methods let RowSet persistence providers be
registered or de-registered with the factory mechanism. This
allows additional synchronization provider implementations to be made
available to RowSet objects at run time.
Applications can apply a degree of filtering to determine the level of
synchronization that a SyncProvider implementation offers.
The following criteria determine whether a provider is
made available to a RowSet object:
RowSet object, and
the SyncFactory does not contain a reference to this provider,
a SyncFactoryException is thrown stating that the synchronization
provider could not be found.
RowSet implementation is instantiated with a specified
provider and the specified provider has been properly registered, the
requested provider is supplied. Otherwise a SyncFactoryException
is thrown.
RowSet object does not specify a
SyncProvider implementation and no additional
SyncProvider implementations are available, the reference
implementation providers are supplied.
SyncProvider Implementations
Both vendors and developers can register SyncProvider
implementations using one of the following mechanisms.
-Drowset.provider.classname=com.fred.providers.HighAvailabilityProvider
#Default JDBC RowSet sync providers listing # # Optimistic synchronization provider rowset.provider.classname.0=com.sun.rowset.providers.RIOptimisticProvider rowset.provider.vendor.0=Sun Microsystems Inc rowset.provider.version.0=1.0 # XML Provider using standard XML schema rowset.provider.classname.1=com.sun.rowset.providers.RIXMLProvider rowset.provider.vendor.1=Sun Microsystems Inc. rowset.provider.version.1=1.0The
SyncFactory checks this file and registers the
SyncProvider implementations that it contains. A
developer or vendor can add other implementations to this file.
For example, here is a possible addition:
rowset.provider.classname.2=com.fred.providers.HighAvailabilityProvider
rowset.provider.vendor.2=Fred, Inc.
rowset.provider.version.2=1.0
SyncFactory will attempt to load
SyncProvider implementations from that JNDI context.
For example, the following code fragment registers a provider implementation
on a JNDI context. This is something a deployer would normally do. In this
example, MyProvider is being registered on a CosNaming
namespace, which is the namespace used by J2EE resources.
import javax.naming.*;
Hashtable svrEnv = new Hashtable();
srvEnv.put(Context.INITIAL_CONTEXT_FACTORY, "CosNaming");
Context ctx = new InitialContext(svrEnv);
com.fred.providers.MyProvider = new MyProvider();
ctx.rebind("providers/MyProvider", syncProvider);
SyncFactory instance. This allows the SyncFactory
to browse within the JNDI context looking for SyncProvider
implementations.
Hashtable appEnv = new Hashtable();
appEnv.put(Context.INITIAL_CONTEXT_FACTORY, "CosNaming");
appEnv.put(Context.PROVIDER_URL, "iiop://hostname/providers");
Context ctx = new InitialContext(appEnv);
SyncFactory.registerJNDIContext(ctx);
If a RowSet object attempts to obtain a MyProvider
object, the SyncFactory will try to locate it. First it searches
for it in the system properties, then it looks in the resource files, and
finally it checks the JNDI context that has been set. The SyncFactory
instance verifies that the requested provider is a valid extension of the
SyncProvider abstract class and then gives it to the
RowSet object. In the following code fragment, a new
CachedRowSet object is created and initialized with
env, which contains the binding to MyProvider.
Hashtable env = new Hashtable();
env.put(SyncFactory.ROWSET_SYNC_PROVIDER, "com.fred.providers.MyProvider");
CachedRowSet crs = new com.sun.rowset.CachedRowSetImpl(env);
Further details on these mechanisms are available in the
javax.sql.rowset.spi package specification.
SyncProvider,
SyncFactoryException| Field Summary | |
|---|---|
static String |
ROWSET_SYNC_PROVIDER
The standard property-id for a synchronization provider implementation name. |
static String |
ROWSET_SYNC_PROVIDER_VERSION
The standard property-id for a synchronization provider implementation version tag. |
static String |
ROWSET_SYNC_VENDOR
The standard property-id for a synchronization provider implementation vendor name. |
| Method Summary | |
|---|---|
static SyncProvider |
getInstance(String providerID)
Returns the SyncProvider instance identified by providerID. |
static Logger |
getLogger()
Returns the logging object for applications to retrieve synchronization events posted by SyncProvider implementations. |
static Enumeration<SyncProvider> |
getRegisteredProviders()
Returns an Enumeration of currently registered synchronization providers. |
static SyncFactory |
getSyncFactory()
Returns the SyncFactory singleton. |
static void |
registerProvider(String providerID)
Adds the the given synchronization provider to the factory register. |
static void |
setJNDIContext(Context ctx)
Sets the initial JNDI context from which SyncProvider implementations can be retrieved from a JNDI namespace |
static void |
setLogger(Logger logger)
Sets the logging object to be used by the SyncProvider
implementation provided by the SyncFactory. |
static void |
setLogger(Logger logger,
Level level)
Sets the logging object that is used by SyncProvider
implementations provided by the SyncFactory SPI. |
static void |
unregisterProvider(String providerID)
Removes the designated currently registered synchronization provider from the Factory SPI register. |
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
| Field Detail |
|---|
public static String ROWSET_SYNC_PROVIDER
public static String ROWSET_SYNC_VENDOR
public static String ROWSET_SYNC_PROVIDER_VERSION
| Method Detail |
|---|
public static void registerProvider(String providerID)
throws SyncFactoryException
SyncProvider specification for the
required naming conventions for SyncProvider
implementations.
Synchronization providers bound to a JNDI context can be registered by binding a SyncProvider instance to a JNDI namespace.
SyncProvider p = new MySyncProvider();
InitialContext ic = new InitialContext();
ic.bind ("jdbc/rowset/MySyncProvider", p);
Furthermore, an initial JNDI context should be set with the
SyncFactory using the setJNDIContext method.
The SyncFactory leverages this context to search for
available SyncProvider objects bound to the JNDI
context and its child nodes.
providerID - A String object with the unique ID of the
synchronization provider being registered
SyncFactoryException - if an attempt is made to supply an empty
or null provider namesetJNDIContext(javax.naming.Context)public static SyncFactory getSyncFactory()
SyncFactory singleton.
SyncFactory instance
public static void unregisterProvider(String providerID)
throws SyncFactoryException
providerID - The unique-id of the synchronization provider
SyncFactoryException - If an attempt is made to
unregister a SyncProvider implementation that was not registered.
public static SyncProvider getInstance(String providerID)
throws SyncFactoryException
SyncProvider instance identified by providerID.
providerID - the unique identifier of the provider
SyncProvider implementation
SyncFactoryException - If the SyncProvider cannot be found or
some error was encountered when trying to invoke this provider.
public static Enumeration<SyncProvider> getRegisteredProviders()
throws SyncFactoryException
RowSet implementation may use any provider in
the enumeration as its SyncProvider object.
At a minimum, the reference synchronization provider allowing RowSet content data to be stored using a JDBC driver should be possible.
SyncFactoryExceptionpublic static void setLogger(Logger logger)
SyncProvider
implementation provided by the SyncFactory. All
SyncProvider implementations can log their events to
this object and the application can retrieve a handle to this
object using the getLogger method.
logger - A Logger object instance
public static void setLogger(Logger logger,
Level level)
SyncProvider
implementations provided by the SyncFactory SPI. All
SyncProvider implementations can log their events
to this object and the application can retrieve a handle to this
object using the getLogger method.
logger - a Logger object instancelevel - a Level object instance indicating the degree of logging
required
public static Logger getLogger()
throws SyncFactoryException
SyncFactoryException - if no logging object has been set.
public static void setJNDIContext(Context ctx)
throws SyncFactoryException
ctx - a valid JNDI context
SyncFactoryException - if the supplied JNDI context is null
|
JavaTM 2 Platform Standard Ed. 5.0 |
|||||||||
| PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
| SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD | |||||||||
Copyright 2004 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.