Programming WebLogic JTA
WebLogic Server includes the ability to monitor currently running transactions and ensure that adequate information is captured in the case of heuristic completion. It also provides the ability to monitor performance of database queries, transactional requests, and bean methods.
In addition to the standard JTA exceptions, WebLogic Server provides the class
weblogic.transaction.RollbackException. This class extends
javax.transaction.RollbackException and preserves the original reason for a rollback. Before rolling a transaction back, or before setting it to
rollbackonly, an application can supply a reason for the rollback. All rollbacks triggered inside the transaction service set the reason (for example, timeouts, XA errors, unchecked exceptions in
beforeCompletion, or inability to contact the transaction manager). Once set, the reason cannot be overwritten.
The Transaction Service assigns a transaction identifier (
Xid) to each transaction. This ID can be used to isolate information about a specific transaction in a log file. You can retrieve the transaction identifier using the
getXID method in the
weblogic.transaction.Transaction interface. For detailed information on methods for getting the transaction identifier, see the
WebLogic JTA provides extensions to
javax.transaction.Transaction that support transaction naming and user-defined properties. These extensions are included in the
The transaction name indicates a type of transaction (for example, funds transfer or ticket purchase) and should not be confused with the transaction ID, which identifies a unique transaction on a server. The transaction name makes it easier to identify a transaction type in the context of an exception or a log file.
User-defined properties are key/value pairs, where the key is a string identifying the property and the value is the current value assigned to the property. Transaction property values must be objects that implement the
Serializable interface. You manage properties in your application using the set and get methods defined in the
weblogic.transaction.Transaction interface. Once set, properties stay with a transaction during its entire lifetime and are passed between machines as the transaction travels through the system. Properties are saved in the transaction log, and are restored during crash recovery processing. If a transaction property is set more than once, the latest value is retained.
The Java Transaction API provides transaction status codes using the
javax.transaction.Status class. Use the
getStatusAsString method in
weblogic.transaction.Transaction to return the status of the transaction as a string. The string contains the major state as specified in
javax.transaction.Status with an additional minor state (such as
Transaction statistics are provided for all transactions handled by the transaction manager on a server. These statistics include the number of total transactions, transactions with a specific outcome (such as committed, rolled back, or heuristic completion), rolled back transactions by reason, and the total time that transactions were active. For detailed information on transaction statistics, see the Administration Console Online Help.
The Administration Console allows you to monitor transactions and to specify the transaction log file prefix. Monitoring and logging tasks are performed at the server level. Transaction statistics are displayed for a specific server and each server has a transaction log file.
For details, see Monitoring Transactions in the Administration Console Online Help.