OpenJDK 27 · javax.sql.rowset.spi.SyncProvider · APIdia, the JavaDoc alternative

The synchronization mechanism that provides reader/writer capabilities for disconnected 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.

1.0 Naming Convention for Implementations

As a guide to naming SyncProvider implementations, the following should be noted:

The name for a SyncProvider implementation is its fully qualified class name.
It is recommended that vendors supply a 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.

2.0 How a `RowSet` Object Gets Its Provider

A disconnected Rowset object may get access to a SyncProvider object in one of the following two ways:

Using a constructor

      CachedRowSet crs = new CachedRowSet(
                 "com.fred.providers.HighAvailabilitySyncProvider");

Using the 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.

3.0 Violations and Synchronization Issues

If an update between a disconnected 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.

4.0 Updatable SQL VIEWs

It is possible for any disconnected or connected 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.

5.0 `SyncProvider` Constants

The SyncProvider 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.

Constants to indicate the synchronization grade of a SyncProvider object
- SyncProvider.GRADE_NONE
- SyncProvider.GRADE_MODIFIED_AT_COMMIT
- SyncProvider.GRADE_CHECK_ALL_AT_COMMIT
- SyncProvider.GRADE_LOCK_WHEN_MODIFIED
- SyncProvider.GRADE_LOCK_WHEN_LOADED
Constants to indicate what locks are set on the data source
- SyncProvider.DATASOURCE_NO_LOCK
- SyncProvider.DATASOURCE_ROW_LOCK
- SyncProvider.DATASOURCE_TABLE_LOCK
- SyncProvider.DATASOURCE_DB_LOCK
Constants to indicate whether a SyncProvider object can perform updates to an SQL VIEW
These constants are explained in the preceding section (4.0).
- SyncProvider.UPDATABLE_VIEW_SYNC
- SyncProvider.NONUPDATABLE_VIEW_SYNC

Field Summary

Modifier and Type	Field and Description
public 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.
public static final int	DATASOURCE_NO_LOCK Indicates that no locks remain on the originating data source.
public 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.
public 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.
public static final int	GRADE_CHECK_ALL_AT_COMMIT Indicates a high level optimistic synchronization grade with respect to the originating data source.
public static final int	GRADE_CHECK_MODIFIED_AT_COMMIT Indicates a low level optimistic synchronization grade with respect to the originating data source.
public static final int	GRADE_LOCK_WHEN_LOADED Indicates the most pessimistic synchronization grade with respect to the originating data source.
public static final int	GRADE_LOCK_WHEN_MODIFIED Indicates a pessimistic synchronization grade with respect to the originating data source.
public static final int	GRADE_NONE Indicates that no synchronization with the originating data source is provided.
public 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.
public 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.

Access	Constructor and Description
public	SyncProvider() Creates a default `SyncProvider` object.

Method Summary

Modifier and Type	Method and Description
public abstract int	Returns: a constant indicating the current level of data source lock active in this `SyncProvider` object; one of the following: SyncProvider.DATASOURCE_NO_LOCK, SyncProvider.DATASOURCE_ROW_LOCK, SyncProvider.DATASOURCE_TABLE_LOCK, SyncProvider.DATASOURCE_DB_LOCK getDataSourceLock() Returns the current data source lock severity level active in this `SyncProvider` implementation.
public abstract int	Returns: an int that is one of the following constants: SyncProvider.GRADE_NONE, SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT, SyncProvider.GRADE_CHECK_ALL_AT_COMMIT, SyncProvider.GRADE_LOCK_WHEN_MODIFIED, SyncProvider.GRADE_LOCK_WHEN_LOADED getProviderGrade() Returns a constant indicating the grade of synchronization a `RowSet` object can expect from this `SyncProvider` object.
public abstract String	Returns: a `String` object with the fully qualified class name of this `SyncProvider` object getProviderID() Returns the unique identifier for this `SyncProvider` object.
public abstract RowSetReader	Returns: a `javax.sql.RowSetReader` object getRowSetReader() Returns a `javax.sql.RowSetReader` object, which can be used to populate a `RowSet` object with data.
public abstract RowSetWriter	Returns: a `javax.sql.RowSetWriter` object getRowSetWriter() Returns a `javax.sql.RowSetWriter` object, which can be used to write a `RowSet` object's data back to the underlying data source.
public abstract String	Returns: a `String` detailing the vendor name of this `SyncProvider` implementation getVendor() Returns the vendor name of this `SyncProvider` instance
public abstract String	Returns: a `String` detailing the release version of the `SyncProvider` implementation getVersion() Returns the release version of this `SyncProvider` instance.
public abstract void	setDataSourceLock(int 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, datasource_lock) Sets a lock on the underlying data source at the level indicated by datasource_lock.
public abstract int	Returns: an `int` saying whether this `SyncProvider` object supports updating an SQL `VIEW`; one of the following: SyncProvider.UPDATABLE_VIEW_SYNC, SyncProvider.NONUPDATABLE_VIEW_SYNC 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.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

DATASOURCE_DB_LOCK	back to summary
public 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.

DATASOURCE_NO_LOCK	back to summary
public static final int DATASOURCE_NO_LOCK Indicates that no locks remain on the originating data source. This is the default lock setting for all `SyncProvider` implementations unless otherwise directed by a `RowSet` object.

DATASOURCE_ROW_LOCK	back to summary
public 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.

DATASOURCE_TABLE_LOCK	back to summary
public 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.

GRADE_CHECK_ALL_AT_COMMIT	back to summary
public static final int GRADE_CHECK_ALL_AT_COMMIT Indicates a high level optimistic synchronization grade with respect to the originating data source. A `SyncProvider` implementation returning this grade will check all rows, including rows that have not changed.

GRADE_CHECK_MODIFIED_AT_COMMIT	back to summary
public static final int GRADE_CHECK_MODIFIED_AT_COMMIT Indicates a low level optimistic synchronization grade with respect to the originating data source. A `SyncProvider` implementation returning this grade will check only rows that have changed.

GRADE_LOCK_WHEN_LOADED	back to summary
public static final int GRADE_LOCK_WHEN_LOADED Indicates the most pessimistic synchronization grade with respect to the originating data source. A `SyncProvider` implementation returning this grade will lock the entire view and/or table affected by the original statement used to populate a `RowSet` object.

GRADE_LOCK_WHEN_MODIFIED	back to summary
public static final int GRADE_LOCK_WHEN_MODIFIED Indicates a pessimistic synchronization grade with respect to the originating data source. A `SyncProvider` implementation returning this grade will lock the row in the originating data source.

GRADE_NONE	back to summary
public static final int GRADE_NONE Indicates that no synchronization with the originating data source is provided. A `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.

NONUPDATABLE_VIEW_SYNC	back to summary
public 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.

UPDATABLE_VIEW_SYNC	back to summary
public 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.

SyncProvider	back to summary
public SyncProvider() Creates a default `SyncProvider` object.

Method Detail

getDataSourceLock back to summary

getDataSourceLock	back to summary
public abstract int getDataSourceLock() throws SyncProviderException Returns the current data source lock severity level active in this `SyncProvider` implementation. Returns:int a constant indicating the current level of data source lock active in this `SyncProvider` object; one of the following: SyncProvider.DATASOURCE_NO_LOCK, SyncProvider.DATASOURCE_ROW_LOCK, SyncProvider.DATASOURCE_TABLE_LOCK, SyncProvider.DATASOURCE_DB_LOCK Exceptions SyncProviderException: if an error occurs determining the data source locking level. See Also `setDataSourceLock`

public abstract int getDataSourceLock() throws SyncProviderException

Returns the current data source lock severity level active in this SyncProvider implementation.

Returns:int

a constant indicating the current level of data source lock active in this SyncProvider object; one of the following:

          SyncProvider.DATASOURCE_NO_LOCK,
          SyncProvider.DATASOURCE_ROW_LOCK,
          SyncProvider.DATASOURCE_TABLE_LOCK,
          SyncProvider.DATASOURCE_DB_LOCK

Exceptions

SyncProviderException:: if an error occurs determining the data source locking level.

See Also

setDataSourceLock

getProviderGrade back to summary

getProviderGrade	back to summary
public abstract int getProviderGrade() Returns a constant indicating the grade of synchronization a `RowSet` object can expect from this `SyncProvider` object. Returns:int an int that is one of the following constants: SyncProvider.GRADE_NONE, SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT, SyncProvider.GRADE_CHECK_ALL_AT_COMMIT, SyncProvider.GRADE_LOCK_WHEN_MODIFIED, SyncProvider.GRADE_LOCK_WHEN_LOADED

public abstract int getProviderGrade()

Returns a constant indicating the grade of synchronization a RowSet object can expect from this SyncProvider object.

Returns:int: an int that is one of the following constants: SyncProvider.GRADE_NONE, SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT, SyncProvider.GRADE_CHECK_ALL_AT_COMMIT, SyncProvider.GRADE_LOCK_WHEN_MODIFIED, SyncProvider.GRADE_LOCK_WHEN_LOADED

getProviderID back to summary

getProviderID	back to summary
public abstract String getProviderID() Returns the unique identifier for this `SyncProvider` object. Returns:String a `String` object with the fully qualified class name of this `SyncProvider` object

public abstract String getProviderID()

Returns the unique identifier for this SyncProvider object.

Returns:String: a String object with the fully qualified class name of this SyncProvider object

getRowSetReader back to summary

getRowSetReader	back to summary
public abstract RowSetReader getRowSetReader() Returns a `javax.sql.RowSetReader` object, which can be used to populate a `RowSet` object with data. Returns:RowSetReader a `javax.sql.RowSetReader` object

public abstract RowSetReader getRowSetReader()

Returns a javax.sql.RowSetReader object, which can be used to populate a RowSet object with data.

Returns:RowSetReader: a javax.sql.RowSetReader object

getRowSetWriter back to summary

getRowSetWriter	back to summary
public 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. Returns:RowSetWriter a `javax.sql.RowSetWriter` object

public 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.

Returns:RowSetWriter: a javax.sql.RowSetWriter object

getVendor back to summary

getVendor	back to summary
public abstract String getVendor() Returns the vendor name of this `SyncProvider` instance Returns:String a `String` detailing the vendor name of this `SyncProvider` implementation

public abstract String getVendor()

Returns the vendor name of this SyncProvider instance

Returns:String: a String detailing the vendor name of this SyncProvider implementation

getVersion back to summary

getVersion	back to summary
public abstract String getVersion() Returns the release version of this `SyncProvider` instance. Returns:String a `String` detailing the release version of the `SyncProvider` implementation

public abstract String getVersion()

Returns the release version of this SyncProvider instance.

Returns:String: a String detailing the release version of the SyncProvider implementation

setDataSourceLock back to summary

setDataSourceLock	back to summary
public abstract void setDataSourceLock(int datasource_lock) throws SyncProviderException Sets a lock on the underlying data source at the level indicated by datasource_lock. This should cause the `SyncProvider` to adjust its behavior by increasing or decreasing the level of optimism it provides for a successful synchronization. Parameters datasource_lock:int 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, Exceptions SyncProviderException: if an unsupported data source locking level is set. See Also `getDataSourceLock`

public abstract void setDataSourceLock(int datasource_lock) throws SyncProviderException

Sets a lock on the underlying data source at the level indicated by datasource_lock. This should cause the SyncProvider to adjust its behavior by increasing or decreasing the level of optimism it provides for a successful synchronization.

Parameters

datasource_lock:int

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,

Exceptions

SyncProviderException:: if an unsupported data source locking level is set.

See Also

getDataSourceLock

supportsUpdatableView back to summary

supportsUpdatableView	back to summary
public 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. Returns:int an `int` saying whether this `SyncProvider` object supports updating an SQL `VIEW`; one of the following: SyncProvider.UPDATABLE_VIEW_SYNC, SyncProvider.NONUPDATABLE_VIEW_SYNC

public 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.

Returns:int: an int saying whether this SyncProvider object supports updating an SQL VIEW; one of the following: SyncProvider.UPDATABLE_VIEW_SYNC, SyncProvider.NONUPDATABLE_VIEW_SYNC

public abstract Class SyncProvider

1.0 Naming Convention for Implementations

2.0 How a `RowSet` Object Gets Its Provider

3.0 Violations and Synchronization Issues

4.0 Updatable SQL VIEWs

5.0 `SyncProvider` Constants

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public abstract Class SyncProvider

1.0 Naming Convention for Implementations

2.0 How a RowSet Object Gets Its Provider

3.0 Violations and Synchronization Issues

4.0 Updatable SQL VIEWs

5.0 SyncProvider Constants

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

2.0 How a `RowSet` Object Gets Its Provider

5.0 `SyncProvider` Constants