public abstract class SyncProvider extends Object
RowSet
objects. A SyncProvider
implementation is a class that extends the SyncProvider
abstract class. A SyncProvider
implementation is identified by a unique ID, which is its fully qualified class name. This name must be registered with the SyncFactory
SPI, thus making the implementation available to all RowSet
implementations. The factory mechanism in the reference implementation uses this name to instantiate the implementation, which can then provide a RowSet
object with its reader (a javax.sql.RowSetReader
object) and its writer (a javax.sql.RowSetWriter
object).
The Jdbc RowSet
Implementations specification provides two reference implementations of the SyncProvider
abstract class: RIOptimisticProvider
and RIXMLProvider
. The RIOptimisticProvider
can set any RowSet
implementation with a RowSetReader
object and a RowSetWriter
object. However, only the RIXMLProvider
implementation can set an XmlReader
object and an XmlWriter
object. A WebRowSet
object uses the XmlReader
object to read data in XML format to populate itself with that data. It uses the XmlWriter
object to write itself to a stream or java.io.Writer
object in XML format.
SyncProvider
implementations, the following should be noted: SyncProvider
implementation is its fully qualified class name. SyncProvider
implementation in a package named providers
. For instance, if a vendor named Fred, Inc. offered a SyncProvider
implementation, you could have the following:
Vendor name: Fred, Inc. Domain name of vendor: com.fred Package name: com.fred.providers SyncProvider implementation class name: HighAvailabilityProvider Fully qualified class name of SyncProvider implementation: com.fred.providers.HighAvailabilityProvider
The following line of code uses the fully qualified name to register this implementation with the SyncFactory
static instance.
SyncFactory.registerProvider( "com.fred.providers.HighAvailabilityProvider");
The default SyncProvider
object provided with the reference implementation uses the following name:
com.sun.rowset.providers.RIOptimisticProvider
Vendors should refer to the reference implementation synchronization providers for additional guidance on how to implement a new SyncProvider
implementation.
RowSet
Object Gets Its ProviderRowset
object may get access to a SyncProvider
object in one of the following two ways: CachedRowSet crs = new CachedRowSet( "com.fred.providers.HighAvailabilitySyncProvider");
setSyncProvider
method CachedRowSet crs = new CachedRowSet(); crs.setSyncProvider("com.fred.providers.HighAvailabilitySyncProvider");
By default, the reference implementations of the RowSet
synchronization providers are always available to the Java platform. If no other pluggable synchronization providers have been correctly registered, the SyncFactory
will automatically generate an instance of the default SyncProvider
reference implementation. Thus, in the preceding code fragment, if no implementation named com.fred.providers.HighAvailabilitySyncProvider
has been registered with the SyncFactory
instance, crs will be assigned the default provider in the reference implementation, which is com.sun.rowset.providers.RIOptimisticProvider
.
RowSet
object and a data source violates the original query or the underlying data source constraints, this will result in undefined behavior for all disconnected RowSet
implementations and their designated SyncProvider
implementations. Not defining the behavior when such violations occur offers greater flexibility for a SyncProvider
implementation to determine its own best course of action. A SyncProvider
implementation may choose to implement a specific handler to handle a subset of query violations. However if an original query violation or a more general data source constraint violation is not handled by the SyncProvider
implementation, all SyncProvider
objects must throw a SyncProviderException
.
RowSet
object to be populated from an SQL query that is formulated originally from an SQL VIEW
. While in many cases it is possible for an update to be performed to an underlying view, such an update requires additional metadata, which may vary. The SyncProvider
class provides two constants to indicate whether an implementation supports updating an SQL VIEW
. NONUPDATABLE_VIEW_SYNC
- Indicates that a SyncProvider
implementation does not support synchronization with an SQL VIEW
as the underlying source of data for the RowSet
object. UPDATABLE_VIEW_SYNC
- Indicates that a SyncProvider
implementation supports synchronization with an SQL VIEW
as the underlying source of data. The default is for a RowSet
object not to be updatable if it was populated with data from an SQL VIEW
.
SyncProvider
ConstantsSyncProvider
class provides three sets of constants that are used as return values or parameters for SyncProvider
methods. SyncProvider
objects may be implemented to perform synchronization between a RowSet
object and its underlying data source with varying degrees of care. The first group of constants indicate how synchronization is handled. For example, GRADE_NONE
indicates that a SyncProvider
object will not take any care to see what data is valid and will simply write the RowSet
data to the data source. GRADE_MODIFIED_AT_COMMIT
indicates that the provider will check only modified data for validity. Other grades check all data for validity or set locks when data is modified or loaded. SyncProvider
object SyncProvider
object can perform updates to an SQL VIEW
Modifier and Type | Field | Description |
---|---|---|
static final int |
DATASOURCE_DB_LOCK |
Indicates that a lock is placed on the entire data source that is the source of data for the RowSet object that is using this SyncProvider object. |
static final int |
DATASOURCE_NO_LOCK |
Indicates that no locks remain on the originating data source. |
static final int |
DATASOURCE_ROW_LOCK |
Indicates that a lock is placed on the rows that are touched by the original SQL statement used to populate the RowSet object that is using this SyncProvider object. |
static final int |
DATASOURCE_TABLE_LOCK |
Indicates that a lock is placed on all tables that are touched by the original SQL statement used to populate the RowSet object that is using this SyncProvider object. |
static final int |
GRADE_CHECK_ALL_AT_COMMIT |
Indicates a high level optimistic synchronization grade with respect to the originating data source. |
static final int |
GRADE_CHECK_MODIFIED_AT_COMMIT |
Indicates a low level optimistic synchronization grade with respect to the originating data source. |
static final int |
GRADE_LOCK_WHEN_LOADED |
Indicates the most pessimistic synchronization grade with respect to the originating data source. |
static final int |
GRADE_LOCK_WHEN_MODIFIED |
Indicates a pessimistic synchronization grade with respect to the originating data source. |
static final int |
GRADE_NONE |
Indicates that no synchronization with the originating data source is provided. |
static final int |
NONUPDATABLE_VIEW_SYNC |
Indicates that a SyncProvider implementation does not support synchronization between a RowSet object and the SQL VIEW used to populate it. |
static final int |
UPDATABLE_VIEW_SYNC |
Indicates that a SyncProvider implementation supports synchronization between a RowSet object and the SQL VIEW used to populate it. |
Constructor | Description |
---|---|
SyncProvider() |
Creates a default SyncProvider object. |
Modifier and Type | Method | Description |
---|---|---|
abstract int |
getDataSourceLock() |
Returns the current data source lock severity level active in this SyncProvider implementation. |
abstract int |
getProviderGrade() |
Returns a constant indicating the grade of synchronization a RowSet object can expect from this SyncProvider object. |
abstract String |
getProviderID() |
Returns the unique identifier for this SyncProvider object. |
abstract RowSetReader |
getRowSetReader() |
Returns a javax.sql.RowSetReader object, which can be used to populate a RowSet object with data. |
abstract RowSetWriter |
getRowSetWriter() |
Returns a javax.sql.RowSetWriter object, which can be used to write a RowSet object's data back to the underlying data source. |
abstract String |
getVendor() |
Returns the vendor name of this SyncProvider instance |
abstract String |
getVersion() |
Returns the release version of this SyncProvider instance. |
abstract void |
setDataSourceLock |
Sets a lock on the underlying data source at the level indicated by datasource_lock. |
abstract int |
supportsUpdatableView() |
Returns whether this SyncProvider implementation can perform synchronization between a RowSet object and the SQL VIEW in the data source from which the RowSet object got its data. |
public static final int GRADE_NONE
SyncProvider
implementation returning this grade will simply attempt to write updates in the RowSet
object to the underlying data source without checking the validity of any data.public static final int GRADE_CHECK_MODIFIED_AT_COMMIT
SyncProvider
implementation returning this grade will check only rows that have changed.public static final int GRADE_CHECK_ALL_AT_COMMIT
SyncProvider
implementation returning this grade will check all rows, including rows that have not changed.public static final int GRADE_LOCK_WHEN_MODIFIED
SyncProvider
implementation returning this grade will lock the row in the originating data source.public static final int GRADE_LOCK_WHEN_LOADED
SyncProvider
implementation returning this grade will lock the entire view and/or table affected by the original statement used to populate a RowSet
object.public static final int DATASOURCE_NO_LOCK
SyncProvider
implementations unless otherwise directed by a RowSet
object.public static final int DATASOURCE_ROW_LOCK
RowSet
object that is using this SyncProvider
object.public static final int DATASOURCE_TABLE_LOCK
RowSet
object that is using this SyncProvider
object.public static final int DATASOURCE_DB_LOCK
RowSet
object that is using this SyncProvider
object.public static final int UPDATABLE_VIEW_SYNC
SyncProvider
implementation supports synchronization between a RowSet
object and the SQL VIEW
used to populate it.public static final int NONUPDATABLE_VIEW_SYNC
SyncProvider
implementation does not support synchronization between a RowSet
object and the SQL VIEW
used to populate it.public SyncProvider()
SyncProvider
object.public abstract String getProviderID()
SyncProvider
object.String
object with the fully qualified class name of this SyncProvider
objectpublic abstract RowSetReader getRowSetReader()
javax.sql.RowSetReader
object, which can be used to populate a RowSet
object with data.javax.sql.RowSetReader
objectpublic abstract RowSetWriter getRowSetWriter()
javax.sql.RowSetWriter
object, which can be used to write a RowSet
object's data back to the underlying data source.javax.sql.RowSetWriter
objectpublic abstract int getProviderGrade()
RowSet
object can expect from this SyncProvider
object.public abstract void setDataSourceLock(int datasource_lock) throws SyncProviderException
SyncProvider
to adjust its behavior by increasing or decreasing the level of optimism it provides for a successful synchronization.datasource_lock
- one of the following constants indicating the severity level of data source lock required: SyncProvider.DATASOURCE_NO_LOCK, SyncProvider.DATASOURCE_ROW_LOCK, SyncProvider.DATASOURCE_TABLE_LOCK, SyncProvider.DATASOURCE_DB_LOCK,
SyncProviderException
- if an unsupported data source locking level is set.public abstract int getDataSourceLock() throws SyncProviderException
SyncProvider
implementation.SyncProvider
object; one of the following: SyncProvider.DATASOURCE_NO_LOCK, SyncProvider.DATASOURCE_ROW_LOCK, SyncProvider.DATASOURCE_TABLE_LOCK, SyncProvider.DATASOURCE_DB_LOCK
SyncProviderException
- if an error occurs determining the data source locking level.public abstract int supportsUpdatableView()
SyncProvider
implementation can perform synchronization between a RowSet
object and the SQL VIEW
in the data source from which the RowSet
object got its data.int
saying whether this SyncProvider
object supports updating an SQL VIEW
; one of the following: SyncProvider.UPDATABLE_VIEW_SYNC, SyncProvider.NONUPDATABLE_VIEW_SYNCpublic abstract String getVersion()
SyncProvider
instance.String
detailing the release version of the SyncProvider
implementationpublic abstract String getVendor()
SyncProvider
instanceString
detailing the vendor name of this SyncProvider
implementation
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https://docs.oracle.com/en/java/javase/21/docs/api/java.sql.rowset/javax/sql/rowset/spi/SyncProvider.html