xlobsessionimpl.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: XlobSessionImpl.java,v 1.4 2005/07/17 16:31:49 jmettraux Exp $
 */

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

package openwfe.org.xlob;

import openwfe.org.Utils;
import openwfe.org.MapUtils;
import openwfe.org.ServiceException;
import openwfe.org.ApplicationContext;
import openwfe.org.xml.XmlUtils;
import openwfe.org.xml.XmlCoder;
import openwfe.org.xml.XmlCodingException;
import openwfe.org.sql.SqlUtils;
import openwfe.org.sql.ds.OwfeDataSource;
import openwfe.org.engine.expressions.FlowExpressionId;


/**
 * An implementation of XlobSession
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: XlobSessionImpl.java,v 1.4 2005/07/17 16:31:49 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public class XlobSessionImpl

    implements XlobSession

{

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

    //
    // CONSTANTS & co

    private final static String FEI_FIELDS =
        "prefix, "+
        "engineId, "+
        "initialEngineId, "+
        "wfdUrl, "+
        "wfdName, "+
        "wfdRevision, "+
        "wfInstanceId, "+
        "expressionName, "+
        "expressionId";

    private final static String FIELDS =
        FEI_FIELDS + ", xldoc";

    /**
     * The parameter 'xlobPrefix'.
     */
    public final static String P_PREFIX
        = "xlobPrefix";

    //
    // FIELDS

    private java.sql.Connection connection = null;
    private OwfeDataSource dataSource = null;

    private String prefix = null;

    //
    // CONSTRUCTORS

    //
    // METHODS

    private java.sql.Connection getConnection ()
        throws java.sql.SQLException
    {
        if (this.connection != null) return this.connection;

        return this.dataSource.getConnection();
    }

    private void releaseConnection ()
    {
        if (this.dataSource != null) this.dataSource.releaseConnection();
    }

    private java.sql.PreparedStatement prepareStatement
        (final String header, FlowExpressionId fei)
    throws 
        java.sql.SQLException
    {
        log.debug("prepareStatement() for "+header+" / "+fei);

        if (fei == null) fei = new FlowExpressionId();

        final StringBuffer sb = new StringBuffer();

        sb
            .append(header)
            .append(" FROM xldocument")

            .append(" WHERE")
            .append(" prefix = ?");

        if (fei.getEngineId() != null)
            sb.append(" AND engineId LIKE ?");

        if (fei.getInitialEngineId() != null)
            sb.append(" AND initialEngineId LIKE ?");

        if (fei.getWorkflowDefinitionUrl() != null)
            sb.append(" AND wfdUrl LIKE ?");

        if (fei.getWorkflowDefinitionName() != null)
            sb.append(" AND wfdName LIKE ?");

        if (fei.getWorkflowDefinitionRevision() != null)
            sb.append(" AND wfdRevision LIKE ?");

        if (fei.getWorkflowInstanceId() != null)
            sb.append(" AND wfInstanceId LIKE ?");

        if (fei.getExpressionName() != null)
            sb.append(" AND expressionName LIKE ?");

        if (fei.getExpressionId() != null)
            sb.append(" AND expressionId LIKE ?");

        //
        // prepare statement

        final java.sql.PreparedStatement ps = 
            getConnection().prepareStatement(sb.toString());

        int i = 1;

        ps.setString(i++, this.prefix);

        if (fei.getEngineId() != null)
            ps.setString(i++, fei.getEngineId());

        if (fei.getInitialEngineId() != null)
            ps.setString(i++, fei.getInitialEngineId());

        if (fei.getWorkflowDefinitionUrl() != null)
            ps.setString(i++, fei.getWorkflowDefinitionUrl());

        if (fei.getWorkflowDefinitionName() != null)
            ps.setString(i++, fei.getWorkflowDefinitionName());

        if (fei.getWorkflowDefinitionRevision() != null)
            ps.setString(i++, fei.getWorkflowDefinitionRevision());

        if (fei.getWorkflowInstanceId() != null)
            ps.setString(i++, fei.getWorkflowInstanceId());

        if (fei.getExpressionName() != null)
            ps.setString(i++, fei.getExpressionName());

        if (fei.getExpressionId() != null)
            ps.setString(i++, fei.getExpressionId());

        return ps;
    }

    private java.sql.ResultSet doQuery 
        (String selectable, final FlowExpressionId fei)
    throws 
        XlobException
    {
        if (selectable == null) selectable = "xldoc";

        log.debug("doQuery() for "+selectable+" / "+fei);

        try
        {
            final java.sql.PreparedStatement ps = 
                prepareStatement("SELECT "+selectable, fei);

            return ps.executeQuery();
        }
        catch (final Throwable t)
        {
            throw new XlobException
                ("query failure", t);
        }
    }

    private org.jdom.Document extract (final java.sql.ResultSet rs)
        throws XlobException
    {
        try
        {
            final java.sql.Clob clob = rs.getClob(1);

            final org.jdom.input.SAXBuilder builder = 
                new org.jdom.input.SAXBuilder();

            return builder.build(clob.getCharacterStream());
        }
        catch (final Throwable t)
        {
            throw new XlobException("extraction failure", t);
        }
    }

    private Object extractBean (final java.sql.ResultSet rs)
        throws XlobException
    {
        try
        {
            final org.jdom.Document d = extract(rs);

            return XmlCoder.decode(d);
        }
        catch (final XmlCodingException xce)
        {
            throw new XlobException
                ("Failed to decode bean", xce);
        }
    }

    private FlowExpressionId extractExpressionId (final java.sql.ResultSet rs)
        throws java.sql.SQLException
    {
        int i = 1;

        final FlowExpressionId fei = new FlowExpressionId();

        fei.setEngineId(rs.getString(i++));
        fei.setInitialEngineId(rs.getString(i++));
        fei.setWorkflowDefinitionUrl(rs.getString(i++));
        fei.setWorkflowDefinitionName(rs.getString(i++));
        fei.setWorkflowDefinitionRevision(rs.getString(i++));
        fei.setWorkflowInstanceId(rs.getString(i++));
        fei.setExpressionName(rs.getString(i++));
        fei.setExpressionId(rs.getString(i++));

        return fei;
    }

    private boolean toNext (final java.sql.ResultSet rs)
        throws XlobException
    {
        try
        {
            return rs.next();
        }
        catch (final Throwable t)
        {
            throw new XlobException("Failed to fetch next row", t);
        }
    }

    private void close (final java.sql.ResultSet rs)
    {
        try
        {
            rs.close();
        }
        catch (final Throwable t)
        {
            // ignore
        }
    }

    private void close (final java.sql.Statement st)
    {
        try
        {
            st.close();
        }
        catch (final Throwable t)
        {
            // ignore
        }
    }

    //
    // METHODS from XlobSession

    /**
     * Inits the session (once it got instantiated).
     *
     * @param prefix each OpenWFE using an xlob session must explicitely
     * specify a prefix like 'worklist' or 'engine-alpha'.
     */
    public void init (final java.sql.Connection con, final String prefix)
    {
        this.connection = con;
        this.prefix = prefix;
    }

    /**
     * Inits the session (once it got instantiated).
     *
     * @param prefix each OpenWFE using an xlob session must explicitely
     * specify a prefix like 'worklist' or 'engine-alpha'.
     */
    public void init (OwfeDataSource ds, String prefix)
    {
        this.dataSource = ds;
        this.prefix = prefix;
    }

    /**
     * Closes this session.
     */
    public void close ()
    {
        try
        {
            if (this.connection != null) this.connection.close();
        }
        catch (final Throwable t)
        {
            log.info("close() problem", t);
        }
    }

    /**
     * Updates or inserts an XML document for a given fei.
     */
    public void store (final FlowExpressionId fei, final org.jdom.Document doc)
        throws XlobException
    {
        store(fei, XmlUtils.toString(doc));
    }

    /**
     * Updates or inserts an XML document for a given fei.
     */
    public void store (final FlowExpressionId fei, final org.jdom.Element elt)
        throws XlobException
    {
        store(fei, XmlUtils.toString(elt));
    }

    /**
     * Turns a bean into an XML document (openwfe.org.xml.XmlCoder) and
     * stores it.
     */
    public void storeBean (final FlowExpressionId fei, final Object bean)
        throws XlobException
    {
        try
        {
            store(fei, XmlCoder.encode(bean));
        }
        catch (final XmlCodingException xce)
        {
            throw new XlobException("Failed to encode bean", xce);
        }
    }

    /**
     * Updates or inserts an XML document for a given fei.
     */
    public void store (final FlowExpressionId fei, final String sXml)
        throws XlobException
    {
        java.sql.PreparedStatement ps = null;
        try
        {
            if (isStored(fei)) remove(fei);

            //
            // insert the doc

            final StringBuffer sb = new StringBuffer();

            sb
                .append("INSERT INTO xldocument ")
                .append("(")