xlobworkitemstorage.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: XlobWorkItemStorage.java,v 1.3 2005/07/28 16:33:10 jmettraux Exp $
 */

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

package openwfe.org.xlob.worklist;

import openwfe.org.Utils;
import openwfe.org.MapUtils;
import openwfe.org.ServiceException;
import openwfe.org.ApplicationContext;
import openwfe.org.xml.XmlUtils;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.workitem.CodingException;
import openwfe.org.engine.expressions.FlowExpressionId;
import openwfe.org.engine.impl.workitem.xml.XmlWorkItemCoder;
import openwfe.org.worklist.store.StoreException;
import openwfe.org.worklist.impl.store.AbstractStorage;
import openwfe.org.worklist.impl.store.StoreStat;
import openwfe.org.xlob.XlobSession;
import openwfe.org.xlob.XlobException;


/**
 * An implementation of WorkItemStorage that stores workitems in xlob.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: XlobWorkItemStorage.java,v 1.3 2005/07/28 16:33:10 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class XlobWorkItemStorage

    extends AbstractStorage
    
{

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

    //
    // CONSTANTS & co

    //
    // FIELDS

    /*
     * A session per store : storeName -> xlobSession
     */
    private java.util.Map sessionMap = new java.util.HashMap(20);

    //
    // CONSTRUCTORS

    /*
     * not much to init...
     *
    public void init 
        (final String serviceName, 
         final ApplicationContext context, 
         final java.util.Map serviceParams)
    throws 
        ServiceException
    {
        super.init(serviceName, context, serviceParams);

        log.info("store ready.");
    }
     */

    //
    // METHODS

    /**
     * Returns the XlobSession tied to a store.
     */
    protected synchronized XlobSession getSession (final String storeName)
        throws ServiceException
    {
        XlobSession result = (XlobSession)this.sessionMap.get(storeName);

        if (result != null) return result;

        result = openwfe.org.xlob.XlobSessionImpl
            .createSession(getName()+"_"+storeName, getContext(), getParams());

        this.sessionMap.put(storeName, result);

        return result;
    }

    /**
     * Always return the XmlCoder as found in the coder-configuration.xml
     */
    protected XmlWorkItemCoder getCoder ()
    {
        return (XmlWorkItemCoder)openwfe.org.engine.Definitions
            .getXmlCoder(getContext());
    }

    /**
     * Encodes the given workitem to XML.
     */
    protected org.jdom.Element encode (final InFlowWorkItem wi)
        throws CodingException
    {
        return getCoder().encodeAsXml(wi);
    }

    /**
     * Decodes a workitem from XML.
     */
    protected InFlowWorkItem decode (final org.jdom.Document doc)
        throws CodingException
    {
        return (InFlowWorkItem)getCoder()
            .decode(doc, getContext(), getParams());
    }

    //
    // METHODS from WorkItemStorage

    /**
     * Inserts a workitem into the storage for given store.
     */
    public void storeWorkItem 
        (final String storeName, final InFlowWorkItem wi)
    throws 
        StoreException
    {
        try
        {
            getSession(storeName).store(wi.getLastExpressionId(), encode(wi));
        }
        catch (final Exception e)
        {
            throw new StoreException
                ("failed to store workitem", e);
        }
    }

    /**
     * Removes the workitem from the storage for a given store.
     */
    public void removeWorkItem 
        (final String storeName, final FlowExpressionId fei)
    throws 
        StoreException
    {
        try
        {
            getSession(storeName).remove(fei);
        }
        catch (final Exception e)
        {
            throw new StoreException
                ("failed to remove workitem", e);
        }
    }

    /**
     * Retrieves a workitem given the storename and the workitem id.
     */
    public InFlowWorkItem retrieveWorkItem 
        (final String storeName, final FlowExpressionId fei)
    throws 
        StoreException
    {
        try
        {
            //return (InFlowWorkItem)getSession(storeName).findBean(fei);

            return decode(getSession(storeName).find(fei));
        }
        catch (final Exception e)
        {
            throw new StoreException
                ("failed to retrieve workitem  "+fei, e);
        }
    }

    /**
     * Returns the number of workitems in a store.
     */
    public int countWorkItems 
        (final String storeName)
    throws 
        StoreException
    {
        try
        {
            return getSession(storeName).count(null);
        }
        catch (final Exception e)
        {
            throw new StoreException
                ("failed to count workitems", e);
        }
    }

    /**
     * Returns a list of workitems from a store.
     */
    public java.util.List listWorkItems 
        (final String storeName, final int limit)
    throws 
        StoreException
    {
        try
        {
            final java.util.Set s = 
                getSession(storeName).query(null, limit);

            final java.util.List l = new java.util.ArrayList(s.size());

            final java.util.Iterator it = s.iterator();
            while (it.hasNext())
            {
                final org.jdom.Document d = (org.jdom.Document)it.next();

                l.add(decode(d));
            }

            return l;
        }
        catch (final Exception e)
        {
            throw new StoreException 
                ("failed to list workitems", e);
        }
    }

    //
    // METHODS from Service

    /**
     * Status is outputted as a JDOM element. The status is various
     * information about a service activities and state.
     */
    public org.jdom.Element getStatus ()
    {
        org.jdom.Element result = new org.jdom.Element(getName());

        result.addContent(XmlUtils.getClassElt(this));
        result.addContent(XmlUtils.getRevisionElt("$Id: XlobWorkItemStorage.java,v 1.3 2005/07/28 16:33:10 jmettraux Exp $"));

        //
        // list file names to determine storage content
        
        java.util.List prefixes = null;
        try
        {
            prefixes = getSession("").listPrefixes();
        }
        catch (final Throwable t)
        {
            log.warn("getStatus() couldn't list prefixes", t);
        }

        final StoreStat stat = new StoreStat();

        final java.util.Iterator it = prefixes.iterator();
        while (it.hasNext())
        {
            final String s = (String)it.next();
            final String storeName = s.substring(getName().length()+1);

            try
            {
                final java.util.Iterator lit = 
                    getSession(storeName).listExpressionIds().iterator();

                while (lit.hasNext())
                {
                    final FlowExpressionId fei = (FlowExpressionId)lit.next();

                    final String flowDef = 
                        fei.getWorkflowDefinitionName() + " " +
                        fei.getWorkflowDefinitionRevision();

                    final String flowId = 
                        fei.getParentWorkflowInstanceId();

                    stat.put(storeName, flowDef, flowId);
                }
            }
            catch (final Throwable t)
            {
                log.warn("failed to include stats for store '"+storeName+"'");
            }
        }

        result.addContent(stat.render());

        //
        // the end

        return result;
    }

    //
    // STATIC METHODS

}