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Class bea.jolt.pool.SessionPool

java.lang.Object
   |
   +----bea.jolt.pool.Factory
           |
           +----bea.jolt.pool.SessionPool

public class SessionPool

extends Factory

This class provides several methods that are part of the session pool administrative API. When using session pools with BEA WebLogic, administration is done via the BEA WebLogic console. A user does not need to access this administrative API directly.

The call and startTransaction methods are not part of the administrative API. They are used to submit requests to a BEA TUXEDO system.

Multiple service requests can be executed in a single transaction. When a transaction starts, the session pool picks the least busy connection and puts it in transactional mode. All service requests associated with that transaction are then sent via the selected connection. The connection associated with the transaction is not available for other requests until the transaction either commits or aborts. The transaction should commit or abort before a response is sent to the client, otherwise the connection does not return to the pool of available connections.

A session pool attempts to reestablish failed connections. When a connection fails, in-process transactions and requests fail and return errors. The session pool only reestablishes connections, it does not resubmit failed requests.

Refer to the BEA WebLogic Administrators Guide for information on configuring a session pool.

Author:

Copyright (c) 1999 by BEA Systems, Inc. All Rights Reserved.

call(String, DataSet, Transaction)

Invokes a BEA TUXEDO service.

getConnection(int)

This method is part of the session pool administrative API.

getMaxConnections()

This method is part of the session pool administrative API.

isSuspended()

This method is part of the session pool administrative API.

setMaxConnections(int)

This method is part of the session pool administrative API.

startTransaction(int)

Starts a transaction.

 public Result call(String svcname,
                    DataSet input,
                    Transaction tran) throws SessionPoolException, ApplicationException, ServiceException, TransactionException

Invokes a BEA TUXEDO service. The name of the service to be invoked is passed to this method as a String svcname. Input parameters for the service are passed in input. If no input parameters are required for the service, input should be null. The names of the elements in the input must match the names of the service parameters.

To invoke multiple services in a transaction, create a Transaction object (see startTransaction()) and pass the Transaction object as the parameter tran. If this service is not part of a transaction tran should be null.

If the session pool is suspended or if no connections are available, this method throws a SessionPoolException.

Parameters:

svcname - Name of the service to be invoked

input - DataSet containing service parameters, or null if no input parameters

tran - Transaction object, or null if no transaction

Returns:

Result object, or null

Throws: SessionPoolException

No connections are available.

Throws: ApplicationException

An application error occurred.

Throws: ServiceException

A system error occurred.

Throws: TransactionException

A transaction error occurred.

See Also:

call, call, startTransaction

 public Transaction startTransaction(int timeout) throws SessionPoolException, TransactionException

Starts a transaction. The transaction starts on one of the connections in the session pool. Once a transaction starts on a connection, that connection cannot service requests other than those associated with the started transaction. The transaction must end (commit, abort or timeout) before the connection returns to the pool of available connections. The transaction timeout value is specified in seconds.

Parameters:

timeout - Transaction time-out value in seconds

Returns:

Transaction object

Throws: SessionPoolException

No connections are available.

Throws: TransactionException

A transaction error occurred.

See Also:

call, call

 public int setMaxConnections(int maxCons)

This method is part of the session pool administrative API. It changes the maximum number of connections for a session pool. The number of connections in a session pool can only be increased using this method; shrinking the session pool is not allowed. This method returns -1 if the caller attempts to shrink the pool size.

Parameters:

maxCons - New session pool size

Returns:

New spool size, or -1 for errors

 public int getMaxConnections()

This method is part of the session pool administrative API. It returns the maximum number of connections configured in this session pool. The actual number of established connections might be less than the maximum number configured, since connections are created dynamically depending on load.

Returns:

Configured maximum number of connections

 public boolean isSuspended()

This method is part of the session pool administrative API. It checks if this session pool is suspended. A suspended session pool does not accept any new requests.

Returns:

true if the session pool is suspended; otherwise, false

See Also:

suspendSessionPool

 public Connection getConnection(int index)

This method is part of the session pool administrative API. It returns the connection at index from the session pool. The parameter index must be between zero and maxCons-1 as specified in bea.jolt.pool.SessionPoolManager.createSessionPool.

Parameters:

index - A connection index

Returns:

A Connection object.

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