org.firebirdsql.jdbc
Class FBTpbMapper

java.lang.Object
  org.firebirdsql.jdbc.FBTpbMapper

All Implemented Interfaces:

Serializable

public class FBTpbMapper
extends Object
implements Serializable

This class is provides mapping capabilities between standard JDBC transaction isolation level and Firebird Transaction Parameters Block (TPB).

Author:

Roman Rokytskyy

See Also:

Serialized Form

Field Summary

static String	DEFAULT_MAPPING_RESOURCE
static String	TRANSACTION_NONE Indicates that transactions are not supported.
static String	TRANSACTION_READ_COMMITTED Dirty reads are prevented; non-repeatable reads and phantom reads can occur.
static String	TRANSACTION_READ_UNCOMMITTED Dirty reads, non-repeatable reads and phantom reads can occur.
static String	TRANSACTION_REPEATABLE_READ Dirty reads and non-repeatable reads are prevented; phantom reads can occur.
static String	TRANSACTION_SERIALIZABLE Dirty reads, non-repeatable reads and phantom reads are prevented.

Constructor Summary

FBTpbMapper(GDS gds)
Create instance of this class with the default mapping of JDBC transaction isolation levels to Firebird TPB.

FBTpbMapper(GDS gds, Map stringMapping)
Create instance of this class for the specified string mapping.

FBTpbMapper(GDS gds, String mappingResource, ClassLoader cl)
Create instance of this class and load mapping from the specified resource.

Method Summary

static FBTpbMapper	getDefaultMapper(GDS gds)
TransactionParameterBuffer	getDefaultMapping() Get default mapping.
int	getDefaultTransactionIsolation()
TransactionParameterBuffer	getMapping(int transactionIsolation) Get mapping for the specified transaction isolation level.
static int	getTransactionIsolationLevel(String isolationName) Convert transaction isolation level name into a corresponding constant.
static String	getTransactionIsolationName(int isolationLevel) Convert transaction isolation level into string.
static TransactionParameterBuffer	processMapping(GDS gds, String mapping) Process comma-separated list of keywords and convert them into TPB values.
void	setDefaultTransactionIsolation(int isolationLevel)
void	setMapping(int transactionIsolation, TransactionParameterBuffer tpb) Set mapping for the specified transaction isolation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_MAPPING_RESOURCE

public static final String DEFAULT_MAPPING_RESOURCE

See Also:

Constant Field Values

TRANSACTION_SERIALIZABLE

public static final String TRANSACTION_SERIALIZABLE

Dirty reads, non-repeatable reads and phantom reads are prevented. This level includes the prohibitions in TRANSACTION_REPEATABLE_READ and further prohibits the situation where one transaction reads all rows that satisfy a WHERE condition, a second transaction inserts a row that satisfies that WHERE condition, and the first transaction rereads for the same condition, retrieving the additional "phantom" row in the second read.

See Also:

Constant Field Values

TRANSACTION_REPEATABLE_READ

public static final String TRANSACTION_REPEATABLE_READ

Dirty reads and non-repeatable reads are prevented; phantom reads can occur. This level prohibits a transaction from reading a row with uncommitted changes in it, and it also prohibits the situation where one transaction reads a row, a second transaction alters the row, and the first transaction rereads the row, getting different values the second time (a "non-repeatable read").

See Also:

Constant Field Values

TRANSACTION_READ_COMMITTED

public static final String TRANSACTION_READ_COMMITTED

Dirty reads are prevented; non-repeatable reads and phantom reads can occur. This level only prohibits a transaction from reading a row with uncommitted changes in it.

See Also:

Constant Field Values

TRANSACTION_READ_UNCOMMITTED

public static final String TRANSACTION_READ_UNCOMMITTED

Dirty reads, non-repeatable reads and phantom reads can occur. This level allows a row changed by one transaction to be read by another transaction before any changes in that row have been committed (a "dirty read"). If any of the changes are rolled back, the second transaction will have retrieved an invalid row. This level is not actually supported

See Also:

Constant Field Values

TRANSACTION_NONE

public static final String TRANSACTION_NONE

Indicates that transactions are not supported. This level is not supported

See Also:

Constant Field Values

Constructor Detail

FBTpbMapper

public FBTpbMapper(GDS gds)

Create instance of this class with the default mapping of JDBC transaction isolation levels to Firebird TPB.

FBTpbMapper

public FBTpbMapper(GDS gds,
                   Map stringMapping)
            throws FBResourceException

Create instance of this class for the specified string mapping.

Parameters:

stringMapping - mapping of JDBC transaction isolation to Firebird mapping. Keys and values of this map must be strings. Keys can have following values:

• "TRANSACTION_SERIALIZABLE"
• "TRANSACTION_REPEATABLE_READ"
• "TRANSACTION_READ_COMMITTED"
• "TRANSACTION_READ_UNCOMMITTED"

Values are specified as comma-separated list of following keywords:

• "isc_tpb_consistency"
• "isc_tpb_concurrency"
• "isc_tpb_read_committed"
• "isc_tpb_rec_version"
• "isc_tpb_no_rec_version"
• "isc_tpb_wait"
• "isc_tpb_nowait"
• "isc_tpb_read"
• "isc_tpb_write"
• "isc_tpb_lock_read"
• "isc_tpb_lock_write"
• "isc_tpb_shared"
• "isc_tpb_protected"

It is also allowed to strip "isc_tpb_" prefix from above shown constans. Meaning of these constants and possible combinations you can find in a documentation.

Throws:

FBResourceException - if mapping contains incorrect values.

FBTpbMapper

public FBTpbMapper(GDS gds,
                   String mappingResource,
                   ClassLoader cl)
            throws FBResourceException

Create instance of this class and load mapping from the specified resource.

Parameters:

mappingResource - name of the resource to load.

cl - class loader that should be used to load specified resource.

Throws:

FBResourceException - if resource cannot be loaded or contains incorrect values.

Method Detail

getDefaultMapper

public static FBTpbMapper getDefaultMapper(GDS gds)

getTransactionIsolationName

public static String getTransactionIsolationName(int isolationLevel)

Convert transaction isolation level into string.

Parameters:

isolationLevel - transaction isolation level as integer constant.

Returns:

corresponding string representation.

getTransactionIsolationLevel

public static int getTransactionIsolationLevel(String isolationName)

Convert transaction isolation level name into a corresponding constant.

Parameters:

isolationName - name of the transaction isolation.

Returns:

corresponding constant.

processMapping

public static TransactionParameterBuffer processMapping(GDS gds,
                                                        String mapping)
                                                 throws FBResourceException

Process comma-separated list of keywords and convert them into TPB values.

Parameters:

mapping - comma-separated list of keywords.

Returns:

set containing values corresponding to the specified keywords.

Throws:

FBResourceException - if mapping contains keyword that is not a TPB parameter.

getMapping

public TransactionParameterBuffer getMapping(int transactionIsolation)

Get mapping for the specified transaction isolation level.

Parameters:

transactionIsolation - transaction isolation level.

Returns:

set with TPB parameters.

Throws:

FBResourceException - if specified transaction isolation level is unknown.

setMapping

public void setMapping(int transactionIsolation,
                       TransactionParameterBuffer tpb)

Set mapping for the specified transaction isolation.

Parameters:

transactionIsolation - transaction isolation level.

tpb - TPB parameters.

Throws:

FBResourceException - if incorrect isolation level is specified.

getDefaultMapping

public TransactionParameterBuffer getDefaultMapping()

Get default mapping. Default mapping represents a TPB mapping for the default transaction isolation level (read committed).

Returns:

mapping for the default transaction isolation level.

getDefaultTransactionIsolation

public int getDefaultTransactionIsolation()

setDefaultTransactionIsolation

public void setDefaultTransactionIsolation(int isolationLevel)