org.xchain.namespaces.jta.TransactionCommand.java Source code

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Here is the source code for org.xchain.namespaces.jta.TransactionCommand.java

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/**
 *    Copyright 2011 meltmedia
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package org.xchain.namespaces.jta;

import org.apache.commons.jxpath.JXPathContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.xchain.annotations.Attribute;
import org.xchain.annotations.AttributeType;
import org.xchain.annotations.Element;
import org.xchain.framework.jxpath.ScopedQNameVariables;
import org.xchain.framework.jxpath.Scope;
import org.xchain.framework.lifecycle.ContainerContext;
import org.xchain.impl.ChainImpl;
import javax.transaction.UserTransaction;
import javax.transaction.Status;
import javax.xml.namespace.QName;

/**
 * Demarcate the bounds of a JTA UserTransaction
 * 
 * <code class="source">
 * &lt;jta:transaction xmlns:jta="http://www.xchain.org/jta/1.0" timeout="90"/&gt;
 * </code>
 *
 * @author Mike Moulton
 * @author Christian Trimble
 * @author Josh Kennedy
 * @author John Trimble
 */
@Element(localName = "transaction")
public abstract class TransactionCommand extends ChainImpl {
    public static Logger log = LoggerFactory.getLogger(TransactionCommand.class);

    /**
     * The transaction timeout
     */
    @Attribute(localName = "timeout", type = AttributeType.JXPATH_VALUE, defaultValue = "'90'")
    public abstract Integer getTimeout(JXPathContext context);

    @Attribute(localName = "result", type = AttributeType.QNAME, defaultValue = "{" + Constants.URI + "}"
            + Constants.USER_TRANSACTION)
    public abstract QName getResult(JXPathContext context);

    public boolean execute(JXPathContext context) throws Exception {
        boolean managingTransaction = false;
        boolean result = false;
        UserTransaction transaction = ContainerContext.getJtaLookupStrategy().getUserTransaction();

        if (transaction != null) {
            try {
                // if there is not a transaction running, then start one.
                if (Status.STATUS_ACTIVE != transaction.getStatus()) {
                    managingTransaction = true;
                    transaction.setTransactionTimeout(this.getTimeout(context));
                    transaction.begin();
                }

                // put the transaction into the context.
                ((ScopedQNameVariables) context.getVariables()).declareVariable(getResult(context), transaction,
                        Scope.execution);

                // execute the chain 
                result = super.execute(context);

                // roll back the transaction.
                if (managingTransaction) {
                    transaction.commit();
                }
            } catch (Exception e) {
                if (managingTransaction) {
                    if (transaction.getStatus() != Status.STATUS_NO_TRANSACTION) {
                        transaction.rollback();
                    }
                }
                throw e;
            } finally {
                // TODO: If we defined the transaction variable, then we should remove it.
            }
        } else {
            // TODO: Should this throw an IllegalStateException?  Returning true seems like the wrong behavior.
            result = true;
        }
        return result;
    }

}