jtajobrunshell.java

定时器开源项目, 相对于 jcrontab, Quartz 算是更完整的一个项目, 随著开发的版本上来, 他已经脱离只是写在程序里面的计时器, 在指定的时间或区间, 处理所指定的事件. 也加入了 se

/*
 * Copyright James House (c) 2001-2004
 * 
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met: 1.
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer. 2. Redistributions in
 * binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other
 * materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 */
package org.quartz.ee.jta;

import javax.transaction.Status;
import javax.transaction.SystemException;
import javax.transaction.UserTransaction;

import org.quartz.Scheduler;
import org.quartz.SchedulerException;
import org.quartz.core.JobRunShell;
import org.quartz.core.JobRunShellFactory;
import org.quartz.core.SchedulingContext;

/**
 * <p>
 * An extension of <code>{@link org.quartz.core.JobRunShell}</code> that
 * begins an XA transaction before executing the Job, and commits (or
 * rolls-back) the transaction after execution completes.
 * </p>
 * 
 * @see org.quartz.core.JobRunShell
 * 
 * @author James House
 */
public class JTAJobRunShell extends JobRunShell {

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Data members.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    private UserTransaction ut;

    private UserTransactionHelper userTxHelper;

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Constructors.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    /**
     * <p>
     * Create a JTAJobRunShell instance with the given settings.
     * </p>
     */
    public JTAJobRunShell(JobRunShellFactory jobRunShellFactory,
            Scheduler scheduler, SchedulingContext schdCtxt,
            UserTransactionHelper userTxHelper) {
        super(jobRunShellFactory, scheduler, schdCtxt);

        this.userTxHelper = userTxHelper;
    }

    /*
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     * 
     * Interface.
     * 
     * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     */

    protected void begin() throws SchedulerException {
        try {
            ut = userTxHelper.lookup();

            ut.begin();
        } catch (SchedulerException se) {
            throw se;
        } catch (Exception nse) {

            throw new SchedulerException(
                    "JTAJobRunShell could not start UserTransaction.", nse);
        }
    }

    protected void complete(boolean successfulExecution)
            throws SchedulerException {

        if (ut == null) return;

        try {
            if (ut.getStatus() == Status.STATUS_MARKED_ROLLBACK)
                    successfulExecution = false;
        } catch (SystemException e) {
            throw new SchedulerException(
                    "JTAJobRunShell could not read UserTransaction status.", e);
        }

        if (successfulExecution) {
            try {
                ut.commit();
            } catch (Exception nse) {
                throw new SchedulerException(
                        "JTAJobRunShell could not commit UserTransaction.", nse);
            }
        } else {
            try {
                ut.rollback();
            } catch (Exception nse) {
                throw new SchedulerException(
                        "JTAJobRunShell could not rollback UserTransaction.",
                        nse);
            }
        }

        ut = null;
    }

}