If the DateToStringConverter will revert more than one Date in diffrent threads in the same time. Runtime excetion (NumberFormat....) will be thrown.
The SimpleDateFormat is not thread save!

Solution is:

/*

• JBoss, Home of Professional Open Source
• Copyright 2005, JBoss Inc., and individual contributors as indicated
• by the @authors tag. See the copyright.txt in the distribution for a
• full listing of individual contributors.
  *
• This is free software; you can redistribute it and/or modify it
• under the terms of the GNU Lesser General Public License as
• published by the Free Software Foundation; either version 2.1 of
• the License, or (at your option) any later version.
  *
• This software is distributed in the hope that it will be useful,
• but WITHOUT ANY WARRANTY; without even the implied warranty of
• MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
• Lesser General Public License for more details.
  *
• You should have received a copy of the GNU Lesser General Public
• License along with this software; if not, write to the Free
• Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
• 02110-1301 USA, or see the FSF site: http://www.fsf.org.
  */
  package de.isr.bpm.jbpm.internal;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

import org.jbpm.api.JbpmException;
import org.jbpm.pvm.internal.model.ScopeInstanceImpl;
import org.jbpm.pvm.internal.type.Converter;
import org.jbpm.pvm.internal.type.Variable;

/**

• @author Tom Baeyens
  */
  public class DateToStringConverter implements Converter {

private static final long serialVersionUID = 1L;
String format = "yyyy-MM-dd HH:mm:ss,SSS";

public Object convert(Object o, ScopeInstanceImpl scopeInstance, Variable variable)

{ DateFormat dateFormat = new SimpleDateFormat(format); return dateFormat.format((Date)o); }

public Object revert(Object o, ScopeInstanceImpl scopeInstance, Variable variable) {
try

{ DateFormat dateFormat = new SimpleDateFormat(format); return dateFormat.parseObject((String)o); }

catch (ParseException e)

{ throw new JbpmException("invalid date format in date variable: "+o, e); }

}

public boolean supports(Object value, ScopeInstanceImpl scopeInstance, Variable variable)

{ return ((value!=null) && (value instanceof Date)); }

public void setFormat(String format)

{ this.format = format; }

}