basicfunctions.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: BasicFunctions.java,v 1.13 2005/07/28 16:33:09 jmettraux Exp $
 */

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

package openwfe.org.engine.impl.functions;

import java.text.ParseException;

import openwfe.org.time.Time;
import openwfe.org.engine.workitem.InFlowWorkItem;
import openwfe.org.engine.expressions.FlowExpression;


/**
 * Functions are static methods accepting a workitem and an array of string
 * as arguments, and they return a String. The main functions for OpenWFE are 
 * implemented here.
 *
 * <p><font size=2>CVS Info :
 * <br>$Author: jmettraux $
 * <br>$Id: BasicFunctions.java,v 1.13 2005/07/28 16:33:09 jmettraux Exp $ </font>
 *
 * @author [e-mail]
 */
public abstract class BasicFunctions
{

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

    //
    // CONSTANTS & co

    //
    // static methods (FUNCTIONS)

    /**
     * This function will return the current time as an ISO full date.
     */
    public static String now 
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        return Time.toIsoDate();
    }

    /**
     * This function will return the current date as an ISO date.
     */
    public static String today 
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final String sNow = Time.toIsoDate();
        final int i = sNow.indexOf(" ");
        return sNow.substring(0, i);
    }

    /**
     * Returns the count of attributes (field) the workitem has.
     * fieldCount() and attributeCount() are identical functions.
     */
    public static String attributeCount 
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        return ""+wi.getAttributes().size();
    }

    /**
     * Returns the count of attributes (field) the workitem has.
     * fieldCount() and attributeCount() are identical functions.
     */
    public static String fieldCount
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        return ""+wi.getAttributes().size();
    }

    /**
     * Returns the sum of all of the numeric values given as 'args'.
     */
    public static String sum
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        if (args == null || args.length < 1) 
        {
            log.debug("sum() no args provided, returning '0'");

            return "0";
        }

        float result = 0;

        for (int i=0; i<args.length; i++)
        {
            log.debug("sum() args["+i+"] is >"+args[i]+"<");

            try
            {
                result += Float.parseFloat(args[i]);
            }
            catch (final NumberFormatException nfe)
            {
                // ignore
            }
        }

        return ""+result;
    }

    /**
     * This is an implementation of the lisp 'car' function, given a list as
     * argument, will return the first element (see also 'cdr').
     * So car('a, b, d, e') will yield 'a'.<br>
     * If a second argument is passed (the first being the list), this second
     * argument will be used as the list separator (instead of the 
     * default ',').<br>
     * The separator regex may also be set as a variable "__list_separator__".
     */
    public static String car
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringList sl = new StringList(fe, wi, args);

        return sl.car();
    }

    /**
     * This is the implementation of the 'cdr' lisp function : it will return
     * the list passed as first arg without its head element.
     * The second arg may be an alternate list separator, or else the list
     * separator may be set at flow definition level by setting the
     * "__list_separator__" variable to the appropriate string value.
     */
    public static String cdr
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringList sl = new StringList(fe, wi, args);

        return sl.cdr();
    }

    /**
     * This function follows car() and cdr(), it will return the nth element
     * of a list or '' if the list is empty or n is bigger than the list
     * size. 
     * The first arg is the 'n', the second one is the list itself.<br>
     * So <pre>elt('2', 'a, b, c, d')</pre> will return 'c'.
     */
    public static String elt
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        if (args == null || args.length < 2) return "";

        final int index = Integer.parseInt(args[0]);

        final StringList sl = new StringList(fe, wi, args, 1, 2);
            // sepIndex is set to 2
        
        return sl.elt(index);
    }

    /**
     * This function takes a list as input and returns a the same list but with
     * a different ordering.
     */
    public static String shuffle
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringList sl = new StringList(fe, wi, args);

        return sl.toString();
    }

    /**
     * This function returns the given list reversed.
     */
    public static String reverse
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringList sl = new StringList(fe, wi, args);
        
        sl.reverse();

        return sl.toString();
    }

    /**
     * This function sorts the given list.
     */
    public static String sort
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringList sl = new StringList(fe, wi, args);
        
        sl.sort();

        log.debug("sort() result is >"+sl.toString()+"<");

        return sl.toString();
    }

    /**
     * An alias for timeAdd.
     */
    public static String tadd
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        return timeAdd(fe, wi, args);
    }

    /**
     * This function takes two arguments : an iso date and a time duration,
     * it then returns the date + the time duration.
     */
    public static String timeAdd
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        if (args.length < 2)
        {
            throw new IllegalArgumentException
                ("timeAdd() awaits 2 args.");
        }

        final String sDate = args[0];
        String sDuration = args[1];

        int dmod = +1;
        if (sDuration.startsWith("-"))
        {
            sDuration = sDuration.substring(1);
            dmod = -1;
        }

        long date = 0;
        try
        {
            date = Time.fromIsoDate(sDate);
        }
        catch (final ParseException pe)
        {
            throw new IllegalArgumentException
                ("Failed to parse date '"+sDate+"'");
        }

        final long duration = dmod * Time.parseTimeString(sDuration);

        return Time.toIsoDate(date + duration);
    }


    //
    // RANDOM functions
    //

    /**
     * Returns a random long 
     */
    public static String rlong
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final java.util.Random gen = 
            new java.util.Random(System.currentTimeMillis());

        return ""+gen.nextLong();
    }

    /**
     * Returns a random int 
     */
    public static String rint
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final java.util.Random gen = 
            new java.util.Random(System.currentTimeMillis());

        return ""+gen.nextInt();
    }

    /**
     * Returns a random double, so that 0.0 &lt;= d &lt; 1
     */
    public static String rdouble
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final java.util.Random gen = 
            new java.util.Random(System.currentTimeMillis());

        return ""+gen.nextDouble();
    }

    //
    // some debugging functions

    /**
     * Returns the args wrapped insed &gt; &lt; signs, thus "'a', 'b'"
     * returns "|a| |b|".
     */
    public static String debugargs
        (final FlowExpression fe, final InFlowWorkItem wi, final String[] args)
    {
        final StringBuffer sb = new StringBuffer();

        for (int i=0; i<args.length; i++)
        {
            sb
                .append("|")
                .append(args[i])
                .append("| ");
        }

        final String result = sb.toString().trim();

        log.debug("debugargs() result >"+result+"<");

        return result;
    }

}