atomicqueryitem.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: AtomicQueryItem.java,v 1.14 2005/05/17 16:41:06 jmettraux Exp $
 */

//
// AtomicQueryItem.java
//
// [e-mail]
//
// generated with 
// jtmpl 1.1.00 16.08.2003 John Mettraux ([e-mail])
//

package openwfe.org.xdbc.query;

import openwfe.org.sql.SqlUtils;
import openwfe.org.xdbc.XdbcException;


/**
 * A base class for AttributeQueryItem and ElementQueryItem
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: AtomicQueryItem.java,v 1.14 2005/05/17 16:41:06 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public abstract class AtomicQueryItem

    implements QueryItem

{

    static org.apache.log4j.Logger log = org.apache.log4j.Logger
        .getLogger(AtomicQueryItem.class.getName());

    //
    // CONSTANTS & co

    public final static int LIKE = 0;
    public final static int GREATER = 1;
    public final static int GREATER_OR_EQUALS = 2;
    public final static int LESSER = -1;
    public final static int LESSER_OR_EQUALS = -2;
    public final static int NOT_LIKE = -99;


    public final static String ELTNAME = "eTagName";
    public final static String ELTVALUE = "eText";


    public final static String XML_ATT_VALUE_OPERATOR = "value-operator";

    //
    // FIELDS

    protected int valueOperator = LIKE;

    //
    // CONSTRUCTORS

    //
    // METHODS

    protected boolean childrenMatches (org.jdom.Element elt)
    {
        java.util.Iterator it = elt.getChildren().iterator();
        while (it.hasNext())
            if (matches((org.jdom.Element)it.next())) return true;

        return false;
    }

    /**
     * A value operator is either LIKE, GREATER, GREATER_OR_EQUALS, NOT_LIKE...
     */
    public QueryItem setValueOperator (int valueOperator)
    {
        this.valueOperator = valueOperator;
        return this;
    }
    
    protected String encodeValueOperator ()
    {
        if (this.valueOperator == GREATER) return "greater";
        if (this.valueOperator == GREATER_OR_EQUALS) return "greater-or-equals";
        if (this.valueOperator == LESSER) return "lesser";
        if (this.valueOperator == LESSER_OR_EQUALS) return "lesser-or-equals";
        if (this.valueOperator == NOT_LIKE) return "not-like";
        return "like";
    }

    protected String getValueOperator ()
    {
        if (this.valueOperator == GREATER) return " > ";
        if (this.valueOperator == GREATER_OR_EQUALS) return " >= ";
        if (this.valueOperator == LESSER) return " < ";
        if (this.valueOperator == LESSER_OR_EQUALS) return " <= ";
        if (this.valueOperator == NOT_LIKE) return " NOT LIKE ";
        return " LIKE ";
    }

    protected boolean compare (String a, String b)
    {
        int result = openwfe.org.Utils.compareValues(a, b);

        if (this.valueOperator == GREATER) return (result > 0);
        if (this.valueOperator == GREATER_OR_EQUALS) return (result >= 0);
        if (this.valueOperator == LESSER) return (result < 0);
        if (this.valueOperator == LESSER_OR_EQUALS) return (result <= 0);
        if (this.valueOperator == NOT_LIKE) return (result != 0);
        return (result == 0);
    }

    protected IdSet query 
        (String tableName, String clientIdLike, java.sql.Connection con)
    throws 
        XdbcException
    {
        //
        // prepare query
        
        StringBuffer sb = new StringBuffer();
        
        sb.append("SELECT ");
        sb.append(DOCUMENT_ID);
        sb.append(", "); 
        sb.append(CLIENT_ID);

        sb.append(" FROM ");
        sb.append(tableName);
        sb.append(", "); 
        sb.append(DOCUMENTS);
        sb.append(" WHERE ");

        sb.append(tableName); sb.append("."); sb.append(DOCUMENT_ID);
        sb.append(" = ");
        sb.append(DOCUMENTS); sb.append("."); sb.append("id");
        sb.append(" AND ");

        if (clientIdLike != null)
        {
            sb.append(CLIENT_ID);
            sb.append(" LIKE ");
            sb.append(SqlUtils.prepareString(clientIdLike));
            sb.append(" AND ");
        }

        sb.append(getQueryString());
        //sb.append(";");

        String query = sb.toString();

        log.debug("query() >\n"+query+"\n<");

        //
        // execute query
        
        return executeQuery(con, query);
    }

    //
    // STATIC METHODS

    protected static int decodeValueOperator (String sop)
    {
        if (sop == null) return LIKE;
        if (sop.equals("greater")) return GREATER;
        if (sop.equals("greater-or-equals")) return GREATER_OR_EQUALS;
        if (sop.equals("lesser")) return LESSER;
        if (sop.equals("lesser-or-equals")) return LESSER_OR_EQUALS;
        if (sop.equals("not-like")) return NOT_LIKE;
        return LIKE;
    }

    public static IdSet executeQuery (java.sql.Connection con, String query)
        throws XdbcException
    {
        java.sql.Statement st = null;
        java.sql.ResultSet rs = null;
        try
        {
            st = con.createStatement();
            rs = st.executeQuery(query);

            return IdSet.extractDocumentIds(rs);
        }
        catch (java.sql.SQLException se)
        {
            throw new XdbcException
                ("Failed to query db", se);
        }
        finally
        {
            try
            {
                rs.close();
                st.close();
            }
            catch (Exception e)
            {
                // don't care about it
            }
        }
    }

}