Example usage for javax.transaction TransactionManager getTransaction

Introduction

In this page you can find the example usage for javax.transaction TransactionManager getTransaction.

Prototype

public Transaction getTransaction() throws SystemException;

Source Link

Document

Get the transaction object that represents the transaction context of the calling thread.

Usage

From source file:org.wso2.carbon.humantask.core.scheduler.SimpleScheduler.java

public <T> T execTransaction(Callable<T> transaction, int timeout) throws Exception {
    TransactionManager txm = transactionManager;
    if (txm == null) {
        throw new HumanTaskException(
                "Cannot locate the transaction manager; " + "the server might be shutting down.");
    }/*from   ww w  .  j  a v a2 s .c  o m*/

    // The value of the timeout is in seconds. If the value is zero, 
    // the transaction service restores the default value.
    if (timeout < 0) {
        throw new IllegalArgumentException("Timeout must be positive, received: " + timeout);
    }

    boolean existingTransaction;
    try {
        existingTransaction = txm.getTransaction() != null;
    } catch (Exception ex) {
        String errMsg = "Internal Error, could not get current transaction.";
        throw new HumanTaskException(errMsg, ex);
    }

    // already in transaction, execute and return directly
    if (existingTransaction) {
        return transaction.call();
    }

    // run in new transaction
    Exception ex = null;
    //        int immediateRetryCount = _immediateTransactionRetryLimit;

    transactionManager.setTransactionTimeout(timeout);
    if (log.isDebugEnabled() && timeout != 0) {
        log.debug("Custom transaction timeout: " + timeout);
    }

    try {
        try {
            if (log.isDebugEnabled()) {
                log.debug("Beginning a new transaction");
            }
            txm.begin();
        } catch (Exception e) {
            String errMsg = "Internal Error, could not begin transaction.";
            throw new HumanTaskException(errMsg, e);
        }

        try {
            ex = null;
            return transaction.call();
        } catch (Exception e) {
            ex = e;
        } finally {
            if (ex == null) {
                if (log.isDebugEnabled()) {
                    log.debug("Committing on " + txm + "...");
                }
                try {
                    txm.commit();
                } catch (Exception e2) {
                    ex = e2;
                }
            } else {
                if (log.isDebugEnabled()) {
                    log.debug("Rollbacking on " + txm + "...");
                }
                txm.rollback();
            }

            //                    if (ex != null && immediateRetryCount > 0) {
            //                        if (log.isDebugEnabled()) {
            //                            log.debug("Will retry the transaction in " +
            //                                    _immediateTransactionRetryInterval + " msecs on " +
            //                                    transactionManager + " for error: ", ex);
            //                        }
            //                        Thread.sleep(_immediateTransactionRetryInterval);
            //                    }
        }
    } finally {
        // 0 restores the default value
        transactionManager.setTransactionTimeout(0);
    }

    throw ex;
}