com.ibm.websphere.rsadapter
Class SybaseDataStoreHelper

java.lang.Object
  |
  +--com.ibm.websphere.rsadapter.GenericDataStoreHelper
        |
        +--com.ibm.websphere.rsadapter.SybaseDataStoreHelper
All Implemented Interfaces:
DataStoreHelper, java.io.Serializable
Direct Known Subclasses:
Sybase11DataStoreHelper
public class SybaseDataStoreHelper
extends GenericDataStoreHelper
implements java.io.Serializable

SybaseDataStoreHelper is a DataStoreHelper implementation customized for the Oracle database. When mapping a SQLException, the SQLException mappings from the SybaseDataStoreHelper are searched first, and subsequently, if no match is found, the SQLException mappings from the GenericDataStoreHelper are searched. If you have additional requirements on Sybase consider subclassing this implementation.

SQLException mappings specific to the SybaseDataStoreHelper are the following:

Error CodeSQL StatePortableSQLException subclass
2601DuplicateKeyException.class
JZ0C0StaleConnectionException.class

See Also:
Serialized Form

Field Summary
 
Fields inherited from class com.ibm.websphere.rsadapter.GenericDataStoreHelper
EOLN, genErrorMap, resBundle
 
Fields inherited from interface com.ibm.websphere.rsadapter.DataStoreHelper
CLOUDSCAPE_HELPER, CLOUDSCAPE_NETWORK_SERVER_HELPER, CONNECTJDBC_HELPER, CUSTOM_HELPER, DATADIRECT_HELPER, DB2_390_HELPER, DB2_390_LOCAL_HELPER, DB2_400_HELPER, DB2_HELPER, DB2_UNIVERSAL_HELPER, GENERIC_HELPER, INFORMIX_HELPER, MSSQL_HELPER, ORACLE_HELPER, POTENTIAL_DEADLOCK, POTENTIAL_LOST_UPDATE, SEQUELINK_HELPER, SYBASE_HELPER, SYBASE11_HELPER, TX_REPEATABLE_READ_FORUPDATE, TX_SERIALIZABLE_FORUPDATE, UPDATE_ON_READONLY, WSCONNECTJDBC_HELPER
 
Constructor Summary
SybaseDataStoreHelper(java.util.Properties props)
          This SybaseDataStoreHelper constructor creates a new GenericDataStoreHelper based on the DataStoreHelper properties provided.
 
Method Summary
 void doConnectionSetup(java.sql.Connection conn)
          This method configures a connection before first use.
 void doStatementCleanup(java.sql.PreparedStatement stmt)
          This method cleans up a statement before the statement is returned to the statement cache.
 java.lang.Class findMappingClass(java.sql.SQLException e)
          This method locates the com.ibm.websphere.ce.cm.PortableSQLException subclass corresponding to the specified SQLException, as defined by the SybaseDataStoreHelper, GenericDataStoreHelper, and user-defined SQLException maps.
 int getIsolationLevel(com.ibm.websphere.appprofile.accessintent.AccessIntent aIntent)
          This method determines the transaction isolation level based on the specified AccessIntent.
 java.io.PrintWriter getPrintWriter()
          This method is used to obtain a log writer to set on the DataSource when database logging is enabled (for example: WAS.database=all=enabled).
 void setUserDefinedMap(java.util.Map newmap)
          This method configures a user-defined SQLException map that supersedes default SQLException mappings for the DataStoreHelper.
 java.lang.String showLockInfo(java.util.Properties props)
          This method returns lock information for Sybase.
 
Methods inherited from class com.ibm.websphere.rsadapter.GenericDataStoreHelper
calcPartitionNumber, doConnectionCleanup, getLockType, getMetaData, getResultSetConcurrency, getResultSetType, getXAExceptionContents, hasLostUpdateOrDeadLockOccurred, isBatchUpdateSupportedWithAccessIntent, isConnectionError, mapException, mapException, modifyXAFlag, processGenericCredentials, processSQL, processSQL
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SybaseDataStoreHelper

public SybaseDataStoreHelper(java.util.Properties props)
This SybaseDataStoreHelper constructor creates a new GenericDataStoreHelper based on the DataStoreHelper properties provided. The properties parameter is provided only for future extensibility and is currently unused.

Parameters:
props - DataStoreHelper properties.
Method Detail

doStatementCleanup

public void doStatementCleanup(java.sql.PreparedStatement stmt)
                        throws java.sql.SQLException

This method cleans up a statement before the statement is returned to the statement cache. This method is called only for statements that will be cached. It is called only if at least one of the following statement properties has changed,

  • cursorName
  • escapeProcessing
  • fetchDirection
  • maxFieldSize
  • maxRows
  • queryTimeout

SybaseDataStoreHelper resets all six of the properties listed above.

The following operations do not need to be included in the statement cleanup since they are automatically performed by WebSphere when caching statements,

  • setFetchSize(0)
  • clearParameters()
  • clearWarnings()

A helper class implementing this method may choose to do additional cleanup for the statement. However, this should never include closing the statement, since the statement is intended to be cached.

Specified by:
doStatementCleanup in interface DataStoreHelper
Overrides:
doStatementCleanup in class GenericDataStoreHelper
Parameters:
stmt - the PreparedStatement.
Throws:
java.sql.SQLException - if an error occurs cleaning up the statement.

findMappingClass

public final java.lang.Class findMappingClass(java.sql.SQLException e)

This method locates the com.ibm.websphere.ce.cm.PortableSQLException subclass corresponding to the specified SQLException, as defined by the SybaseDataStoreHelper, GenericDataStoreHelper, and user-defined SQLException maps. Precedence and related details of SQLException mapping are described on the DataStoreHelper.setUserDefinedMap method.

Overriding this method is one of three options you have for modifying SQLException mapping. The other two options are overriding the mapException method and invoking the setUserDefinedMap method to add a user-defined SQLException map.

Overrides:
findMappingClass in class GenericDataStoreHelper
Parameters:
e - The SQLException for which to locate a com.ibm.websphere.ce.cm.PortableSQLException subclass.
Returns:
The com.ibm.websphere.ce.cm.PortableSQLException subclass matching the SQLException, or null if no match was found.
See Also:
SQLException, com.ibm.websphere.ce.cm.PortableSQLException.

getIsolationLevel

public int getIsolationLevel(com.ibm.websphere.appprofile.accessintent.AccessIntent aIntent)
                      throws javax.resource.ResourceException
This method determines the transaction isolation level based on the specified AccessIntent. If the AccessIntent parameter is null, a default value is returned that is appropriate for the database backend. The default transaction isolation level for SybaseDataStoreHelper is Connection.TRANSACTION_REPEATABLE_READ.

In the case where an AccessIntent is specified, SybaseDataStoreHelper computes the transaction isolation level as follows:

  • If the concurrency control is AccessIntent.CONCURRENCY_CONTROL_OPTIMISTIC then a transaction isolation level of Connection.TRANSACTION_READ_COMMITTED is returned.

  • If the concurrency control is AccessIntent.CONCURRENCY_CONTROL_PESSIMISTIC and the access type is AccessIntent.ACCESS_TYPE_READ then a transaction isolation level of Connection.TRANSACTION_REPEATABLE_READ is returned.

  • If the concurrency control is AccessIntent.CONCURRENCY_CONTROL_PESSIMISTIC and the access type is AccessIntent.ACCESS_TYPE_UPDATE then the transation isolation level is determined from the following table based on the pessimistic update lock hint.

    pessimistic update lock hint transaction isolation level
    AccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_NONE
    AccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_WEAKEST_LOCK_AT_LOAD    		 Connection.TRANSACTION_REPEATABLE_READ
    AccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_NOCOLLISION Connection.TRANSACTION_READ_COMMITTED
    AccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_EXCLUSIVE Connection.TRANSACTION_SERIALIZABLE

Specified by:
getIsolationLevel in interface DataStoreHelper
Overrides:
getIsolationLevel in class GenericDataStoreHelper
Parameters:
aIntent - An AccessIntent
Returns:
A transaction isolation level appropriate for the specified AccessIntent.
Throws:
javax.resource.ResourceException - If a transaction isolation level cannot be determined from the AccessIntent.
See Also:
AccessIntent, Connection

showLockInfo

public final java.lang.String showLockInfo(java.util.Properties props)
                                    throws java.lang.Exception

This method returns lock information for Sybase. The props parameter may include the following properties:

  1. user - a user name that has a DBA authority. If not specified, the default value is null.
  2. password - the password corresponding to the user name. If not specified, the default value is null.
  3. serverName - the name of the server where the Sybase database resides.
  4. portNumber - the port where Sybase is listening for connections.
  5. databaseName - the database name. If not specified, a default value of "" (empty string) is used.

Overrides:
showLockInfo in class GenericDataStoreHelper
Parameters:
props - properties containing information needed to connect to the database.
Returns:
the lock information.
Throws:
java.lang.Exception - if an error occurs while collecting the lock information.

setUserDefinedMap

public final void setUserDefinedMap(java.util.Map newmap)

This method configures a user-defined SQLException map that supersedes default SQLException mappings for the DataStoreHelper. The DataStoreHelper implementations provided by WebSphere use SQLException maps to detect fatal connection errors, as well as other specific types of connection errors. A custom DataStoreHelper can alter the default mappings by invoking this method. Invoke this method only from DataStoreHelper classes subclassing this class. Do not invoke this method directly from application code. Internal WebSphere code does not invoke this method.

Example usage of the setUserDefinedMap method:

    public MyCustomDataStoreHelper()
    {
       ...
       java.util.HashMap MyErrorMap = new java.util.HashMap(2);
       myErrorMap.put(new Integer(-801), MyDuplicateKeyException.class);
       myErrorMap.put(new Integer(-1015), MyStaleConnectionException.class);
       setUserDefinedMap(myErrorMap);
       ...
    }

User-defined exception mapping takes priority over all other exception mapping done by a DataStoreHelper. This differs from the WAS 4.0 DataSource model where mapping by Error Code always takes precedence over mapping by SQL State.

For example, assume the following exception mappings are defined:

 User-defined mappings:
 SQL State  S1000 --> UserDefinedException
 
 Default mappings:
 Error Code 23505 --> DuplicateKeyException
 SQL State  S1000 --> StaleConnectionException

Given the above mappings, if a SQLException is received with SQL State S1000 and Error Code 23505, the WebSphere DataStoreHelper implementations map the exception to UserDefinedException, whereas the WAS 4.0 DataSource map the exception to DuplicateKeyException.

Additionally, mapping done by the WebSphere DataStoreHelpers does not include mapping by chained exceptions when no match is found for the original exception.

Specified by:
setUserDefinedMap in interface DataStoreHelper
Overrides:
setUserDefinedMap in class GenericDataStoreHelper
Parameters:
newmap - a mapping of SQLException SQL States and Error Codes to com.ibm.websphere.ce.cm.PortableSQLException subclasses. The key for the Map must be a String (representing the SQL State) or an Integer (representing the Error Code). The value for the Map must be a subclass of com.ibm.websphere.ce.cm.PortableSQLException. User-defined subclasses are permitted, but are required to declare a public constructor accepting a SQLException as the single parameter. Void.class may also be used for the value, in which case any existing mapping for the specified SQL State or Error Code is removed.
See Also:
SQLException, PortableSQLException

getPrintWriter

public java.io.PrintWriter getPrintWriter()
This method is used to obtain a log writer to set on the DataSource when database logging is enabled (for example: WAS.database=all=enabled). By default, null is returned and a java.io.PrintWriter instance created by WebSphere is used. You can override this method to return a different java.io.PrintWriter instance instead of the default.

Specified by:
getPrintWriter in interface DataStoreHelper
Overrides:
getPrintWriter in class GenericDataStoreHelper
Returns:
java.io.PrintWriter.
Since:
WAS 5.0.1

doConnectionSetup

public void doConnectionSetup(java.sql.Connection conn)
                       throws java.sql.SQLException

This method configures a connection before first use. This method is invoked only when a new connection to the database is created. It is not invoked when connections are reused from the connection pool.

SybaseDataStoreHelper checks the SQLWarnings on the connection to determine if a connection was made to the requested database. If the requested database does not exist, Sybase's standard behavior is to connect a "default database" and log a SQLWarning. This method scans for this SQLWarning and if found, throws a SQLException based on the contents of the SQLWarning indicating that a connection to the requested database could not be established.

Specified by:
doConnectionSetup in interface DataStoreHelper
Overrides:
doConnectionSetup in class GenericDataStoreHelper
Parameters:
conn - the connection to set up.
Throws:
java.sql.SQLException - if connection setup cannot be completed successfully.
Since:
WAS 5.0.2

 

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