abstractcompositeflowexpression.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 
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * $Id: AbstractCompositeFlowExpression.java,v 1.23 2005/05/17 16:40:23 jmettraux Exp $
 */

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

package openwfe.org.engine.expressions;

import openwfe.org.Utils;
import openwfe.org.ReflectionUtils;
import openwfe.org.ApplicationContext;
import openwfe.org.engine.Definitions;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.expressions.raw.RawExpression;
import openwfe.org.engine.expressions.map.ExpressionMap;


/**
 * The beginning of the implementation of a CompositeFlowExpression : examples 
 * of fully implemented composite flowExpressions include SequenceExpression,
 * ConcurrenceExpression and the like.
 * A composite expression is an expression with a list of children. These
 * children are referenced as FlowExpressionId instances. Of course, each
 * FlowExpressionId points to a FlowExpression in the expression pool.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Date: 2005/05/17 16:40:23 $
 * <br>$Id: AbstractCompositeFlowExpression.java,v 1.23 2005/05/17 16:40:23 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public abstract class AbstractCompositeFlowExpression

    extends AbstractFlowExpression

    implements CompositeFlowExpression

{

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

    //
    // FIELDS

    /**
     * A list of FlowExpressionId instances pointing to the children 
     * of this composite expression.
     */
    private java.util.List children = new java.util.ArrayList(0);

    //
    // CONSTRUCTORS

    //
    // BEAN METHODS

    public java.util.List getChildren () { return this.children; }

    public void setChildren (final java.util.List l) { this.children = l; }

    //
    // OVERRIDEN METHODS

    /**
     * This method sets the workflow instance id in the expression and
     * in all of its children
     */
    public void initWorkflowInstanceId (final String workflowInstanceId)
    {
        super.initWorkflowInstanceId(workflowInstanceId);

        final java.util.Iterator it = this.children.iterator();
        while (it.hasNext())
        {
            final FlowExpressionId fei = (FlowExpressionId)it.next();
            fei.setWorkflowInstanceId(workflowInstanceId);
        }
    }

    //
    // METHODS from CompositeFlowExpression

    /**
     * A droflo method, moves up a child up one position
     */
    public void moveUpChild (FlowExpressionId fei)
    {
        int i = this.children.indexOf(fei);
        this.children.remove(i);
        i--;
        if (i < 0) i = 0;
        this.children.add(i, fei);
    }

    /**
     * A droflo method, moves up a child down one position
     */
    public void moveDownChild (FlowExpressionId fei)
    {
        int i = this.children.indexOf(fei);
        this.children.remove(i);
        i++;
        if (i >= this.children.size())
        {
            this.children.add(fei);
            return;
        }
        this.children.add(i, fei);
    }

    /**
     * Replacing a child with another expression.
     * Of course children are not directly referenced, instead FlowExpressionId
     * instances are used.
     */
    public boolean replaceChild 
        (final FlowExpressionId thisFei, final FlowExpressionId thatFei)
    {
        return Utils.replace(getChildren(), thisFei, thatFei);
    }

    //
    // METHODS from FlowExpression

    /* *
     * This method is called by the pool when the expression gets removed
     * from it.
     * /
    public void release ()
    {
        super.release();

        if (getChildren() == null) return;

        final java.util.Iterator it = getChildren().iterator();
        while (it.hasNext())
        {
            final FlowExpressionId child = (FlowExpressionId)it.next();

            //
            // release child (and its children then)

            getExpressionPool().release(child);
        }
    }
    */

    /**
     * Cancels this expression, this result in the cancelling of 
     * each of the child expression this composite references.
     */
    public InFlowWorkItem cancel ()
        throws ApplyException
    {
        super.cancel();

        InFlowWorkItem wi = null;

        java.util.Iterator it = this.children.iterator();

        //
        // returns the first non-null workitem returned

        while (it.hasNext())
        {
            final InFlowWorkItem i = getExpressionPool()
                .childCancel((FlowExpressionId)it.next());

            if (wi == null) wi = i;
        }

        return wi;
    }

    //
    // METHODS

    /**
     * Adds a child to the expression (as last child)
     */
    public void addChild (FlowExpressionId fei)
    {
        this.children.add(fei);
    }

    /**
     * Removes a child from this composite expression
     */
    public void removeChild (FlowExpressionId fei)
    {
        this.children.remove(fei);
    }

    /**
     * Inits the expression.
     */
    public void init 
        (final ApplicationContext context,
         final FlowExpressionId parentId, 
         final FlowExpressionId id, 
         final RawExpression generatingExpression,
         final Object raw,
         final InFlowWorkItem currentWi)
    throws 
        BuildException
    {
        super.init
            (context, 
             parentId,
             id,
             generatingExpression,
             raw,
             currentWi);

        if (generatingExpression != null)
            this.children = generatingExpression.prepareChildren(currentWi);
    }

    /**
     * Clones this expression, takes care of deep copying everything in it.
     */
    public Object clone ()
    {
        final AbstractCompositeFlowExpression clone = 
            (AbstractCompositeFlowExpression)super.clone();
        
        clone.setChildren(AbstractFlowExpression.deepCopy(getChildren()));

        return clone;
    }

}