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IBM WebSphere Application ServerTM Release 7 |
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java.lang.Objectcom.ibm.websphere.rsadapter.GenericDataStoreHelper
com.ibm.websphere.rsadapter.DB2DataStoreHelper
public class DB2DataStoreHelper
DB2DataStoreHelper
is a DataStoreHelper
implementation
customized for the DB2 legacy CLI-based JDBC driver.
When mapping a SQLException
, the SQLException
mappings from the
DB2DataStoreHelper
are searched first; subsequently, if no match is
found, the SQLException
mappings from the GenericDataStoreHelper
are searched.
If you have additional requirements on DB2, 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 DB2DataStoreHelper
are the following:
Error Code | SQL State | PortableSQLException subclass |
---|---|---|
-30108 | StaleConnectionException.class | |
-30081 | StaleConnectionException.class | |
-30080 | StaleConnectionException.class | |
-6036 | StaleConnectionException.class | |
-1229 | StaleConnectionException.class | |
-1224 | StaleConnectionException.class | |
-1035 | StaleConnectionException.class | |
-1034 | StaleConnectionException.class | |
-1015 | StaleConnectionException.class | |
-924 | StaleConnectionException.class | |
-923 | StaleConnectionException.class | |
-906 | StaleConnectionException.class | |
-803 | DuplicateKeyException.class | |
-518 | StaleConnectionException.class | |
-514 | StaleConnectionException.class | |
58004 | StaleConnectionException.class | |
S1000 | Void.class |
Field Summary | |
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protected static com.ibm.ejs.ras.TraceComponent |
db2Tc
|
Fields inherited from class com.ibm.websphere.rsadapter.GenericDataStoreHelper |
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customDefinedWasDefaultIsoLevel, defaultQueryTimeout, EOLN, genErrorMap, resBundle, tranErrorList |
Constructor Summary | |
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DB2DataStoreHelper(java.util.Properties props)
This DB2DataStoreHelper constructor creates a new
DB2DataStoreHelper based on the DataStoreHelper
properties provided. |
Method Summary | |
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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
DB2DataStoreHelper , GenericDataStoreHelper , and
user-defined SQLException maps. |
int |
getIsolationLevel(AccessIntent aIntent)
This method determines the transaction isolation level based on the specified AccessIntent . |
int |
getLockType(AccessIntent intent)
This method returns a lock type constant based on the update hint value of the specified AccessIntent. |
java.io.PrintWriter |
getPrintWriter()
This method is used to obtain the java.io.PrintWriter to use for logging
when database logging is enabled (for example: WAS.database=all=enabled ). |
int |
getResultSetConcurrency(AccessIntent intent)
This method determines the result set concurrency based on the specified AccessIntent . |
java.lang.String |
getXAExceptionContents(javax.transaction.xa.XAException x)
This method provides a plug-in point for providing meaningful logging information for an XAException . |
boolean |
isBatchUpdateSupportedWithAccessIntent(AccessIntent accessIntent)
This method is used to determine if CMP Entity Beans can support batch updates with the given AccessIntent. |
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 DB2 lock information needed for the RAS subsystem. |
Methods inherited from class java.lang.Object |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Field Detail |
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protected static final com.ibm.ejs.ras.TraceComponent db2Tc
Constructor Detail |
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public DB2DataStoreHelper(java.util.Properties props)
DB2DataStoreHelper
constructor creates a new
DB2DataStoreHelper
based on the DataStoreHelper
properties 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.
props
- DataStoreHelper
properties.Method Detail |
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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.
This class will set a variable db2ZOS to
FALSE
as default value. This method
sets to
TRUE
if the backend system is zOS.
GenericDataStoreHelper
does not perform any connection setup.
doConnectionSetup
in interface DataStoreHelper
doConnectionSetup
in class GenericDataStoreHelper
conn
- the connection to set up.
java.sql.SQLException
- if connection setup cannot be completed successfully.
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 being cached. It is called when at least one of the following statement properties has changed,
DB2DataStoreHelper
resets all of the statement properties listed above
except for the cursorName
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 can choose to do additional cleanup for the statement. However, this must 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.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
DB2DataStoreHelper
, 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
,
PortableSQLException
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 DB2DataStoreHelper
is
Connection.TRANSACTION_REPEATABLE_READ.
In the case where an AccessIntent
is specified,
DB2DataStoreHelper
computes the transaction isolation level as follows:
If the concurrency control is
AccessIntent.CONCURRENCY_CONTROL_OPTIMISTIC
, 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
, 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
, 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 |
getIsolationLevel
in interface DataStoreHelper
getIsolationLevel
in class GenericDataStoreHelper
intent
- An AccessIntent
AccessIntent
.
javax.resource.ResourceException
- If a transaction isolation level cannot be determined
from the AccessIntent
.AccessIntent
,
Connection
public int getResultSetConcurrency(AccessIntent intent) throws javax.resource.ResourceException
AccessIntent
.
DB2DataStoreHelper
always returns
java.sql.ResultSet.CONCUR_READ_ONLY
.
getResultSetConcurrency
in interface DataStoreHelper
getResultSetConcurrency
in class GenericDataStoreHelper
intent
- An AccessIntent
.
java.sql.ResultSet
.
javax.resource.ResourceException
- If a result set concurrency cannot be determined
from the AccessIntent
.AccessIntent
,
ResultSet
public final java.lang.String showLockInfo(java.util.Properties props) throws java.lang.Exception
This method returns DB2 lock information needed for the RAS subsystem. The
props
parameter can include the following properties:
showLockInfo
in class GenericDataStoreHelper
props
- properties containing information needed to connect to the database.
java.lang.Exception
- if an error occurs while collecting the lock information.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 DataStoreHelper
s 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.
You can also use Void.class
for the value, in which case any
existing mapping for the specified SQL State or Error Code is removed.SQLException
,
PortableSQLException
public java.io.PrintWriter getPrintWriter()
java.io.PrintWriter
to use for logging
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.
getPrintWriter
in interface DataStoreHelper
getPrintWriter
in class GenericDataStoreHelper
java.io.PrintWriter
.public boolean isBatchUpdateSupportedWithAccessIntent(AccessIntent accessIntent)
DB2DataStoreHelper
returns false if the concurrency control of the
AccessIntent
is AccessIntent.CONCURRENCY_CONTROL_OPTIMISTIC
,
and otherwise returns true.
isBatchUpdateSupportedWithAccessIntent
in interface DataStoreHelper
isBatchUpdateSupportedWithAccessIntent
in class GenericDataStoreHelper
accessIntent
- AccessIntent
AccessIntent
public int getLockType(AccessIntent intent)
This method returns a lock type constant based on the update hint value of the
specified AccessIntent.
The lock type is used by the persistence manager to determine which locking hints
should be used on a SELECT
statement.
getLockType
in interface DataStoreHelper
getLockType
in class GenericDataStoreHelper
intent
- An AccessIntent
com.ibm.websphere.rsadaper.WSInteractionSpec
:
LOCKTYPE_SELECT
LOCKTYPE_SELECT_FOR_UPDATE
LOCKTYPE_SELECT_FOR_UPDATE_WITH_RS
LOCKTYPE_SELECT_FOR_UPDATE_WITH_RR
AccessIntent
,
WSInteractionSpec
public java.lang.String getXAExceptionContents(javax.transaction.xa.XAException x)
XAException
. The information can include details of the original
exception that caused the XAException
, if applicable.
WebSphere uses this method to obtain trace information for
XAException
s to include in WebSphere trace.
getXAExceptionContents
in interface DataStoreHelper
getXAExceptionContents
in class GenericDataStoreHelper
xae
- the XAException
.
XAException
, for inclusion in
a WebSphere trace.XAException
|
IBM WebSphere Application ServerTM Release 7 |
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