Class InformixDataStoreHelper
- All Implemented Interfaces:
DataStoreHelper
InformixDataStoreHelper is a DataStoreHelper implementation
customized for the Informix database.
When mapping a SQLException, the SQLException mappings from the
InformixDataStoreHelper are searched first, and subsequently, if no match is
found, the SQLException mappings from the GenericDataStoreHelper
are searched.
If you have additional requirements on Informix, consider subclassing this
implementation.
Note: This class and its methods can not be called or referenced directly by user applications.
SQLException mappings specific to the InformixDataStoreHelper
are the following:
| Error Code | SQL State | PortableSQLException subclass |
|---|---|---|
| -79735 | StaleConnectionException.class | |
| -79716 | StaleConnectionException.class | |
| -43207 | StaleConnectionException.class | |
| -27002 | StaleConnectionException.class | |
| -25580 | StaleConnectionException.class | |
| -908 | StaleConnectionException.class | |
| -710 | StaleStatementException.class | |
| -268 | DuplicateKeyException.class | |
| 43012 | StaleConnectionException.class |
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Field Summary
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, DERBY_HELPER, DERBY_NETWORK_SERVER_HELPER, FIRST_TIME_CALLED, GENERIC_HELPER, INFORMIX_HELPER, INFORMIX_JCC_HELPER, MSSQL_HELPER, ORACLE_10G_HELPER, ORACLE_11G_HELPER, ORACLE_HELPER, POTENTIAL_DEADLOCK, POTENTIAL_LOST_UPDATE, PROXY_DS_HELPER, SEQUELINK_HELPER, SUBJECT, SYBASE_HELPER, SYBASE11_HELPER, TX_REPEATABLE_READ_FORUPDATE, TX_SERIALIZABLE_FORUPDATE, UNDEFINED_HELPER, UNDEFINED_ISOLATOIN_LEVEL, UPDATE_ON_READONLY -
Constructor Summary
ConstructorsConstructorDescriptionThisInformixDataStoreHelperconstructor creates a newInformixDataStoreHelperbased on theDataStoreHelperproperties provided. -
Method Summary
Modifier and TypeMethodDescriptionvoiddoConnectionSetup(Connection conn) This method configures a connection before first use.voidThis method cleans up a statement before the statement is returned to the statement cache.final ClassThis method locates thecom.ibm.websphere.ce.cm.PortableSQLExceptionsubclass corresponding to the specifiedSQLException, as defined by theInformixDataStoreHelper,GenericDataStoreHelper, and user-definedSQLExceptionmaps.intgetIsolationLevel(AccessIntent intent) This method determines the transaction isolation level to use as default.This method is used to obtain thejava.io.PrintWriterto use for logging when database logging is enabled (for example:WAS.database=all=enabled).final voidsetUserDefinedMap(Map newmap) This method configures a user-definedSQLExceptionmap that supersedes defaultSQLExceptionmappings for theDataStoreHelper.Methods inherited from class com.ibm.websphere.rsadapter.GenericDataStoreHelper
calcPartitionNumber, doConnectionCleanup, doConnectionCleanupPerCloseConnection, doConnectionCleanupWithValidCheck, doConnectionSetupPerGetConnection, doConnectionSetupPerTransaction, getLockType, getMetaData, getPasswordForUseWithTrustedContextWithAuthentication, getResultSetConcurrency, getResultSetType, getXAExceptionContents, hasLostUpdateOrDeadLockOccurred, isBatchUpdateSupportedWithAccessIntent, isConnectionError, isDuplicateKey, isTransientConnectionError, isUnsupported, mapException, modifyXAFlag, setConfig, showLockInfo
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Constructor Details
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InformixDataStoreHelper
This
InformixDataStoreHelperconstructor creates a newInformixDataStoreHelperbased on theDataStoreHelperproperties provided.The
DataStoreHelperproperties forInformixDataStoreHelperinclude an integer property,informixLockModeWait, representing Informix's timeout when waiting for a lock. A value greater than 0 indicates the number of seconds Informix waits for a lock, after which Informix throws an exception. A value of 0 means Informix does not wait for locks at all, immediately throwing an exception. A value less than 0 means Informix waits indefinitely, until the lock it is waiting for is released. Informix's default behavior is to immediately throw an exception. However, Liberty's default setting forinformixLockModeWait(which is specified asifxIFX_LOCK_MODE_WAITonproperties.informix) is 2, meaning Informix waits for a lock for two seconds before throwing an exception.- Parameters:
props-DataStoreHelperproperties.
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Method Details
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findMappingClass
This method locates the
com.ibm.websphere.ce.cm.PortableSQLExceptionsubclass corresponding to the specifiedSQLException, as defined by theInformixDataStoreHelper,GenericDataStoreHelper, and user-definedSQLExceptionmaps. Precedence and related details ofSQLExceptionmapping are described on theDataStoreHelper.setUserDefinedMapmethod.Overriding this method is one of three options for modifying
SQLExceptionmapping. The other two options are overriding themapExceptionmethod and invoking thesetUserDefinedMapmethod to add a user-definedSQLExceptionmap.- Overrides:
findMappingClassin classGenericDataStoreHelper- Parameters:
e- TheSQLExceptionfor which to locate acom.ibm.websphere.ce.cm.PortableSQLExceptionsubclass.- Returns:
- The
com.ibm.websphere.ce.cm.PortableSQLExceptionsubclass matching theSQLException, or null if no match was found.
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getIsolationLevel
This method determines the transaction isolation level to use as default. The default transaction isolation level forInformixDataStoreHelperisConnection.TRANSACTION_REPEATABLE_READ.- Specified by:
getIsolationLevelin interfaceDataStoreHelper- Overrides:
getIsolationLevelin classGenericDataStoreHelper- Parameters:
intent- always null in Liberty.- Returns:
- A transaction isolation level.
- Throws:
javax.resource.ResourceException- If a transaction isolation level cannot be determined.
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doConnectionSetup
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.
The following actions are prohibited in this method:
- Changing any standard connection properties found on the
java.sql.ConnectionAPI. This includes TransactionIsolationLevel, AutoCommit, Catalog, ReadOnly, TypeMap, and Holdability. - Closing the connection.
The
InformixDataStoreHelperconfigures the InformixIFX_ALLOW_NEWLINEbased on theinformixAllowNewLineDataStoreHelperproperty.- Specified by:
doConnectionSetupin interfaceDataStoreHelper- Overrides:
doConnectionSetupin classGenericDataStoreHelper- Parameters:
conn- the connection to set up.- Throws:
SQLException- if connection setup cannot be completed successfully.
- Changing any standard connection properties found on the
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doStatementCleanup
This method cleans up a statement before the statement is returned to the statement cache. This method is called only for statements being cached. It is called only if at least one of the following statement properties has changed,
- cursorName
- fetchDirection
- maxFieldSize
- maxRows
- queryTimeout
InformixDataStoreHelperresets all of the statement properties listed above except for thecursorNameproperty.The following operations do not need to be included in the statement cleanup since they are automatically performed by Liberty when caching statements,
setFetchSize(0)clearParameters()clearWarnings()
A helper class implementing this method can 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:
doStatementCleanupin interfaceDataStoreHelper- Overrides:
doStatementCleanupin classGenericDataStoreHelper- Parameters:
stmt- the PreparedStatement.- Throws:
SQLException- if an error occurs cleaning up the statement.
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setUserDefinedMap
This method configures a user-defined
SQLExceptionmap that supersedes defaultSQLExceptionmappings for theDataStoreHelper. TheDataStoreHelperimplementations provided by Liberty useSQLExceptionmaps to detect fatal connection errors, as well as other specific types of connection errors. A customDataStoreHelpercan alter the default mappings by invoking this method. Invoke this method only fromDataStoreHelperclasses subclassing this class. Do not invoke this method directly from application code.Example usage of the
setUserDefinedMapmethod:public MyCustomDataStoreHelper() { ... java.util.HashMap MyErrorMap = new java.util.HashMap(2); myErrorMap.put(-801, MyDuplicateKeyException.class); myErrorMap.put(-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
SQLExceptionis received with SQL State S1000 and Error Code 23505, theDataStoreHelperimplementations map the exception toUserDefinedException.Additionally, mapping done by the
DataStoreHelpers does not include mapping by chained exceptions when no match is found for the original exception.- Specified by:
setUserDefinedMapin interfaceDataStoreHelper- Overrides:
setUserDefinedMapin classGenericDataStoreHelper- Parameters:
newmap- a mapping ofSQLExceptionSQL States and Error Codes tocom.ibm.websphere.ce.cm.PortableSQLExceptionsubclasses. The key for the Map must be aString(representing the SQL State) or anInteger(representing the Error Code). The value for the Map must be a subclass ofcom.ibm.websphere.ce.cm.PortableSQLException. User-defined subclasses are permitted, but are required to declare a public constructor accepting aSQLExceptionas the single parameter. You can also useVoid.classfor the value, in which case any existing mapping for the specified SQL State or Error Code is removed.
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getPrintWriter
This method is used to obtain thejava.io.PrintWriterto use for logging when database logging is enabled (for example:WAS.database=all=enabled). By default, null is returned and ajava.io.PrintWriterinstance created by Liberty is used. You can override this method to return a differentjava.io.PrintWriterinstance instead of the default.- Specified by:
getPrintWriterin interfaceDataStoreHelper- Overrides:
getPrintWriterin classGenericDataStoreHelper- Returns:
java.io.PrintWriter.
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