com.ibm.websphere.rsadapter
Class DerbyDataStoreHelper
- java.lang.Object
com.ibm.websphere.rsadapter.GenericDataStoreHelper
com.ibm.websphere.rsadapter.DerbyDataStoreHelper
- public class DerbyDataStoreHelper
- extends GenericDataStoreHelper
DerbyDataStoreHelper is a DataStoreHelper implementation
customized for the Derby database.
When mapping a SQLException, the SQLException mappings from the
DerbyDataStoreHelper are searched first, and subsequently, if no match is
found, the SQLException mappings from the GenericDataStoreHelper
are searched.
If you have additional requirements on Derby you should 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 DerbyDataStoreHelper
are the following:
| Error Code | SQL State | PortableSQLException subclass |
|---|---|---|
| 40000 | StaleConnectionException.class | |
| 45000 | StaleConnectionException.class | |
| 50000 | StaleConnectionException.class | |
| 23505 | DuplicateKeyException.class | |
| 23500 | DuplicateKeyException.class | |
| 23L01 | DuplicateKeyException.class | |
| XCL10 | StaleStatementException.class |
Field Summary
| Modifier and Type | Field and Description |
|---|---|
|
derbyErrorMap
|
|
derbyTc
|
| Fields inherited from class com.ibm.websphere.rsadapter.GenericDataStoreHelper |
|---|
customDefinedWasDefaultIsoLevel, defaultQueryTimeout, EOLN, genErrorMap, resBundle, tranErrorList |
Constructor Summary
| Constructor and Description |
|---|
DerbyDataStoreHelper(java.util.Properties props)
This
DerbyDataStoreHelper constructor creates a new
DerbyDataStoreHelper based on the DataStoreHelper
properties provided.
|
Method Summary
| Modifier and Type | Method and Description |
|---|---|
|
doStatementCleanup(java.sql.PreparedStatement stmt)
This method cleans up a statement before the statement is returned to the statement
cache.
|
|
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
DerbyDataStoreHelper, GenericDataStoreHelper, and
user-defined SQLException maps.
|
|
getIsolationLevel(AccessIntent aIntent)
This method determines the transaction isolation level based on the specified
AccessIntent.
|
|
getResultSetConcurrency(AccessIntent intent)
This method determines the result set concurrency based on the specified
AccessIntent.
|
|
setUserDefinedMap(java.util.Map newmap)
This method configures a user-defined
SQLException map that supersedes
default SQLException mappings for the DataStoreHelper.
|
| Methods inherited from class java.lang.Object |
|---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail
derbyTc
- protected static final com.ibm.ejs.ras.TraceComponent derbyTc
derbyErrorMap
- protected java.util.HashMap derbyErrorMap
Constructor Detail
DerbyDataStoreHelper
- public DerbyDataStoreHelper(java.util.Properties props)
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
- fetchDirection
- maxFieldSize
- maxRows
- queryTimeout
DerbyDataStoreHelper resets all of the statement properties listed above
except for the queryTimeout property.
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.
doStatementCleanup in interface DataStoreHelper
doStatementCleanup in class GenericDataStoreHelper
stmt - the PreparedStatement. 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
DerbyDataStoreHelper, 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.
findMappingClass in class GenericDataStoreHelper
e - The SQLException for which to locate a
com.ibm.websphere.ce.cm.PortableSQLException subclass. com.ibm.websphere.ce.cm.PortableSQLException subclass matching
the SQLException, or null if no match was found. SQLException,
PortableSQLExceptiongetIsolationLevel
- public int getIsolationLevel(AccessIntent aIntent)
- throws javax.resource.ResourceException
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 DerbyDataStoreHelper is
Connection.TRANSACTION_REPEATABLE_READ.
In the case where an AccessIntent is specified,
DerbyDataStoreHelper computes the transaction isolation level as follows:
If the concurrency control is
AccessIntent.CONCURRENCY_CONTROL_OPTIMISTICthen a transaction isolation level ofConnection.TRANSACTION_READ_COMMITTEDis returned.If the concurrency control is
AccessIntent.CONCURRENCY_CONTROL_PESSIMISTICand the access type isAccessIntent.ACCESS_TYPE_READthen a transaction isolation level ofConnection.TRANSACTION_REPEATABLE_READis returned.If the concurrency control is
AccessIntent.CONCURRENCY_CONTROL_PESSIMISTICand the access type isAccessIntent.ACCESS_TYPE_UPDATEthen 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_LOADConnection.TRANSACTION_REPEATABLE_READAccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_NOCOLLISIONConnection.TRANSACTION_READ_COMMITTEDAccessIntent.PESSIMISTIC_UPDATE_LOCK_HINT_EXCLUSIVEConnection.TRANSACTION_SERIALIZABLE
getIsolationLevel in interface DataStoreHelper
getIsolationLevel in class GenericDataStoreHelper
aIntent - An AccessIntent AccessIntent. javax.resource.ResourceException - If a transaction isolation level cannot be determined
from the AccessIntent. AccessIntent,
ConnectiongetResultSetConcurrency
- public int getResultSetConcurrency( AccessIntent intent)
- throws javax.resource.ResourceException
AccessIntent.
DerbyDataStoreHelper always returns
java.sql.ResultSet.CONCUR_READ_ONLY, as
java.sql.ResultSet.CONCUR_READ_ONLY is the only result set concurrency
value supported by Derby.
intent - An AccessIntent. java.sql.ResultSet. javax.resource.ResourceException - If a result set concurrency cannot be determined
from the AccessIntent. AccessIntent,
ResultSetsetUserDefinedMap
- 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.
setUserDefinedMap in interface DataStoreHelper
setUserDefinedMap in class GenericDataStoreHelper
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. SQLException,
PortableSQLException
DerbyDataStoreHelperconstructor creates a newDerbyDataStoreHelperbased on theDataStoreHelperproperties provided. All implementations inheriting from a data store helper must supply this same list of properties to their super class by invoking the constructor of their super class with the list of properties.