simplexmllauncher.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: SimpleXmlLauncher.java,v 1.26 2005/07/27 15:59:02 jmettraux Exp $
 */

//
// SimpleXmlLauncher.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.1.01 2004/05/19 ([e-mail])
//

package openwfe.org.engine.impl.launch;

import openwfe.org.Utils;
import openwfe.org.ReflectionUtils;
import openwfe.org.AbstractService;
import openwfe.org.xml.XmlUtils;
import openwfe.org.engine.Definitions;
import openwfe.org.engine.launch.Launcher;
import openwfe.org.engine.launch.LaunchException;
import openwfe.org.engine.expool.ExpressionPool;
import openwfe.org.engine.workitem.Attribute;
import openwfe.org.engine.workitem.XmlAttribute;
import openwfe.org.engine.workitem.LaunchItem;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.dispatch.DispatchingException;
import openwfe.org.engine.expressions.ApplyException;
import openwfe.org.engine.expressions.BuildException;
import openwfe.org.engine.expressions.FlowExpression;
import openwfe.org.engine.expressions.FlowExpressionId;
import openwfe.org.engine.expressions.DefineExpression;
import openwfe.org.engine.expressions.ProcessDefinition;
import openwfe.org.engine.expressions.raw.RawExpression;
import openwfe.org.engine.expressions.map.ExpressionMap;
import openwfe.org.engine.participants.Participant;
import openwfe.org.engine.participants.ParticipantMap;


/**
 * The vanilla XML openwfe launcher.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: SimpleXmlLauncher.java,v 1.26 2005/07/27 15:59:02 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class SimpleXmlLauncher 

    extends AbstractService

    implements Launcher

{

    private final static org.apache.log4j.Logger log = org.apache.log4j.Logger
        .getLogger(SimpleXmlLauncher.class.getName());

    //
    // CONSTANTS & co

    /**
     * This constant is the name of a system property, when it has a value
     * of 'true', 'ok' or 'yes', XML schema validation will be used
     * against process definitions.
     */
    public final static String VALIDATE
        = "openwfe.org.engine.launcher.validate";

    //
    // FIELDS

    //
    // CONSTRUCTORS

    //
    // METHODS from Launcher

    public String launch (final LaunchItem li)
        throws LaunchException
    {
        final InFlowWorkItem wi = new InFlowWorkItem(li);

        return launch(wi, li.getReplyTo(), li.getWorkflowDefinitionUrl());
    }

    private org.jdom.Element parseXmlDefinition 
        (final String url, 
         final InFlowWorkItem wi, 
         final boolean shouldValidate)
    throws
        Exception
    {
        if (url.startsWith("field:"))
        {
            final String fieldName = url.substring(6);

            final Attribute a = wi.getAttribute(fieldName);

            if (a == null) 
            {
                throw new IllegalArgumentException
                    ("Field '"+fieldName+
                     "' is not present, cannot launch flow defined in it");
            }

            if (a instanceof XmlAttribute)
                return ((XmlAttribute)a).getContent();

            final String sXmlDefinition = a.toString();

            //log.debug("parseXmlDefinition()\n"+sXmlDefinition);

            return XmlUtils.extractXmlElement(sXmlDefinition);
        }

        return XmlUtils.extractXml(url, shouldValidate);
    }

    /**
     * Returns the workflowInstanceId of the newly launched flow.
     */
    public String launch 
        (final InFlowWorkItem wi, 
         FlowExpressionId parentId,
         final String wfdUrl) 
    throws 
        LaunchException
    {
        //
        // remote launch ?

        if (wfdUrl.indexOf("::") > -1)
            return launchExternalProcess(wi, wfdUrl, parentId);

        //
        // local launch

        final String url = Utils.expandUrl(wfdUrl);

        log.debug("launch() request for "+url);

        try
        {
            final ExpressionMap expMap = Definitions
                .getExpressionMap(getContext());

            final org.jdom.Element elt = 
                //XmlUtils.extractXml(url, shouldValidate());
                parseXmlDefinition(url, wi, shouldValidate());

            final RawExpression rootExpression = (RawExpression)ReflectionUtils
                .buildNewInstance(expMap.getRawExpressionClass().getName());

            //
            // misc data

            final String wfdName = elt.getAttributeValue("name");
            final String wfdRevision = elt.getAttributeValue("revision");

            if (wfdName == null || wfdRevision == null)
            {
                throw new LaunchException
                    ("Process definition is missing a 'name' "+
                     "and/or a 'revision' attribute.");
            }

            //
            // determine root expression ids

            if (parentId == null)
                //
                // brand new flow
            {
                parentId = new FlowExpressionId();

                parentId.setEngineId(getContext().getApplicationName());
                parentId.setInitialEngineId(getContext().getApplicationName());
                parentId.setWorkflowDefinitionUrl(url);
                parentId.setWorkflowDefinitionName(wfdName);
                parentId.setWorkflowDefinitionRevision(wfdRevision);

                // expression name and id remain to null !!

                parentId.setWorkflowInstanceId
                    (RawExpression.determineNewWorkflowInstanceId());

                //
                // init the expression

                rootExpression.init(getContext(), parentId, 0, elt);
                    // starting at expressionId '0'
            }
            else
                //
                // determine root expression id manually
            {
                final FlowExpressionId id = new FlowExpressionId();

                id.setEngineId(getContext().getApplicationName());
                id.setInitialEngineId(getContext().getApplicationName());
                id.setWorkflowDefinitionUrl(url);
                id.setWorkflowDefinitionName(wfdName);
                id.setWorkflowDefinitionRevision(wfdRevision);

                id.setExpressionName(elt.getName());
                id.setExpressionId("0");

                id.setWorkflowInstanceId
                    (RawExpression.determineNewWorkflowInstanceId());

                //
                // init the expression

                rootExpression.init(getContext(), parentId, id, elt);
            }

            getExpressionPool().add(rootExpression);
            getExpressionPool().apply(rootExpression.getId(), wi);

            return rootExpression.getId().getWorkflowInstanceId();
        }
        catch (final Throwable t)
        {
            throw new LaunchException("launch failed", t);
        }
    }

    /**
     * Launches an inner subflow (for example for 'iterator' or 'when').
     */
    public FlowExpressionId launchSub
        (final InFlowWorkItem wi,
         final FlowExpressionId parentId,
         final FlowExpressionId templateId)
    throws 
        LaunchException
    {
        log.debug("launchSub() for template "+templateId);
        log.debug("launchSub() parentId is "+parentId);

        RawExpression rawExp = (RawExpression)getExpressionPool()
            .fetch(templateId);

        FlowExpressionId id = null;

        try
        {
            rawExp = rawExp.newInstance(parentId);

            log.debug("launchSub() rawExp.parent was "+rawExp.getParent());

            rawExp.setParent(parentId);
                // especially if it's null

            id = rawExp.getId();

            log.debug("launchSub() rawExp.id is     "+id);
            log.debug("launchSub() rawExp.parent is "+rawExp.getParent());

            //
            // applying