/**
 * Copyright (c) 2009, Ben Fortuna
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  o Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 *  o 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.
 *
 *  o Neither the name of Ben Fortuna nor the names of any other 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.
 */
package net.fortuna.ical4j.vcard.parameter;

import net.fortuna.ical4j.vcard.Parameter;

/**
 * $Id$
 *
 * Created on: 30/12/2008
 *
 * @author Ben
 *
 */
public final class Pref extends Parameter {

    /**
     * 
     */
    private static final long serialVersionUID = -6246880477846039737L;

    /**
     * Support for pre-vCard 4.0 PREF parameter.
     */
    public static final Pref PREF = new Pref();
    
    private final Integer level;
    
    /**
     * @param value
     */
    public Pref(String value) {
        this(Integer.valueOf(value));
    }
    
    /**
     * @param level
     */
    public Pref(Integer level) {
        super(Id.PREF);
        if (level <= 0) {
            throw new IllegalArgumentException("The level of preferredness must be a positive integer");
        }
        this.level = level;
    }

    /**
     * Internal constructor.
     */
    private Pref() {
        super(Id.PREF);
        this.level = null;
    }
    
    /* (non-Javadoc)
     * @see net.fortuna.ical4j.vcard.Parameter#getValue()
     */
    @Override
    public String getValue() {
        if (level > 0) {
            return level.toString();
        }
        return null;
    }
}

@@ -2682,11 +2682,15 @@
 vel 
-%3E 0
+!= null
 ) %7B%0A

Support special case null level