expressionstore.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: ExpressionStore.java,v 1.10 2005/05/17 16:40:23 jmettraux Exp $
 */

//
// ExpressionStore.java
//
// [e-mail]
//

package openwfe.org.engine.expool;

import openwfe.org.Utils;
import openwfe.org.time.Time;
import openwfe.org.engine.expressions.FlowExpression;
import openwfe.org.engine.expressions.FlowExpressionId;


/**
 * An interface for storing expressions as their workflow is instantiated.
 * Used by the ExpressionPool.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Date: 2005/05/17 16:40:23 $
 * <br>$Id: ExpressionStore.java,v 1.10 2005/05/17 16:40:23 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public interface ExpressionStore
{

    //
    // CONSTANTS & co

    //
    // METHODS

    /**
     * Stores the expression
     */
    public void storeExpression (FlowExpression fe)
        throws PoolException;

    /**
     * Removes an expression from the store
     */
    public void unstoreExpression (FlowExpression fe)
        throws PoolException;

    /**
     * Loads expression from the store
     */
    public FlowExpression loadExpression (FlowExpressionId fei)
        throws PoolException;

    /**
     * Load the Ur-Expression (see ExpressionPool for an explanation).
     */
    public FlowExpression loadUrExpression ();

    /* *
     * terminates a flow instance (removes all of its expressions)
     * /
    public void releaseWorkflowInstance (FlowExpression exitExpression)
        throws PoolException;
     */

    /**
     * Returns true if the expression behind the expression id is still
     * alive (present in the store).
     */
    public boolean isExpressionActive (FlowExpressionId fei);

    /**
     * This method is used by the InMemoryExpressionStore when it
     * is restarted to fill its memory storage (the given map) again.
     */
    public void loadAll (java.util.Map expressionMap)
        throws PoolException;

    /**
     * Retrieves a given class of expressions. If the parameter is set to
     * null, will return all the expressions.
     */
    public java.util.Iterator contentIterator (Class assignClass);

    /**
     * Returns the count of expressions in the store.
     */
    public int size ();

}