engineworkitemconsumer.java

一个工作流设计及定义的系统,可以直接与数据库结合进行系统工作流程的定义及应用.

/*
 * Copyright (c) 2005, John Mettraux, OpenWFE.org
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * 
 * . Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.  
 * 
 * . 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.
 * 
 * . Neither the name of the "OpenWFE" nor the names of its contributors may be
 *   used to endorse or promote products derived from this software without
 *   specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
 *
 * $Id: EngineWorkItemConsumer.java,v 1.12 2005/07/21 09:59:55 jmettraux Exp $
 */

//
// EngineWorkItemConsumer.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.0.04 20.11.2001 John Mettraux ([e-mail])
//

package openwfe.org.engine.listen;

import openwfe.org.OpenWfeException;
import openwfe.org.xml.XmlUtils;
import openwfe.org.engine.Definitions;
import openwfe.org.engine.launch.Launcher;
import openwfe.org.engine.expool.ExpressionPool;
import openwfe.org.engine.history.History;
import openwfe.org.engine.workitem.WorkItem;
import openwfe.org.engine.workitem.LaunchItem;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.expressions.ReplyException;


/**
 * The default implementation of a workitem consumer (as used by the engine)
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Date: 2005/07/21 09:59:55 $
 * <br>$Id: EngineWorkItemConsumer.java,v 1.12 2005/07/21 09:59:55 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class EngineWorkItemConsumer

    extends AbstractWorkItemConsumer

{

    private final static org.apache.log4j.Logger cat = org.apache.log4j.Logger
        .getLogger(EngineWorkItemConsumer.class.getName());

    //
    // FIELDS

    //
    // CONSTRUCTORS

    //
    // METHODS

    /**
     * This method looks at the wi and either reply to the corresponding
     * ParticipantExpression either launch a new wf.
     */
    public Object use (final WorkItem wi)
        throws OpenWfeException
    {
        if (wi instanceof LaunchItem)
        {
            return launch((LaunchItem)wi);
        }
        else if (wi instanceof WorkItem)
        {
            reply((InFlowWorkItem)wi);
            return null;
        }
        else
        {
            throw new OpenWfeException
                ("The engine cannot use a WorkItem of class "+
                 wi.getClass().getName());
        }
    }

    protected void reply (final InFlowWorkItem wi)
        throws ReplyException
    {
        Definitions.getHistory(getContext()).log
            (wi.getLastExpressionId(),
             wi,
             History.EVT_INCOMING,
             wi.getParticipantName(),
             ""); 

        Definitions.getExpressionPool(getContext())
            .reply(wi.getLastExpressionId(), wi);
    }

    protected String launch (final LaunchItem li)
        throws OpenWfeException
    {
        //final WorkflowInstanceBuilder builder = 
        //    Definitions.getWorkflowInstanceBuilder(getContext());
        
        final Launcher launcher = Definitions.getLauncher(getContext());

        return launcher.launch(li);
    }

    //
    // METHODS from Service

    public org.jdom.Element getStatus ()
    {
        final org.jdom.Element result = new org.jdom.Element(getName());

        result.addContent(XmlUtils.getClassElt(this));
        result.addContent(XmlUtils.getRevisionElt("$Id: EngineWorkItemConsumer.java,v 1.12 2005/07/21 09:59:55 jmettraux Exp $"));

        return result;
    }

}