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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.InformixDataStoreHelper
public class InformixDataStoreHelper
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 |
Field Summary |
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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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InformixDataStoreHelper(java.util.Properties props)
This InformixDataStoreHelper constructor creates a new
InformixDataStoreHelper 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
InformixDataStoreHelper , GenericDataStoreHelper , and
user-defined SQLException maps. |
int |
getIsolationLevel(AccessIntent aIntent)
This method determines the transaction isolation level based on 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 . |
void |
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 |
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clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public InformixDataStoreHelper(java.util.Properties props)
This InformixDataStoreHelper
constructor creates a new
InformixDataStoreHelper
based on the DataStoreHelper
properties provided.
The DataStoreHelper
properties for InformixDataStoreHelper
include 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,
WebSphere's default setting for informixLockModeWait
is 2, meaning
Informix waits for a lock for two seconds before throwing an exception.
props
- DataStoreHelper
properties.Method Detail |
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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
InformixDataStoreHelper
, 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 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 InformixDataStoreHelper
is
Connection.TRANSACTION_REPEATABLE_READ.
In the case where an AccessIntent
is specified,
InformixDataStoreHelper
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
.
InformixDataStoreHelper
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 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.
The following actions are prohibited in this method:
java.sql.Connection
API. This includes TransactionIsolationLevel,
AutoCommit, Catalog, ReadOnly, TypeMap, and Holdability.The InformixDataStoreHelper
configures the Informix
LOCK MODE WAIT
based on the informixLockModeWait
DataStoreHelper
property. A value
greater than 0 indicates the number of seconds Informix waits for a lock, after which
Informix throws an exception. The informixLockModeWait
value, 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,
WebSphere's default setting for informixLockModeWait
is 2, meaning
Informix waits for a lock for two seconds before throwing an exception.
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 only if at least one of the following statement properties has changed,
InformixDataStoreHelper
resets all of the statement properties listed
above except for the cursorName
and queryTimeout
properties.
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 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.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
.
|
IBM WebSphere Application ServerTM Release 7 |
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