attribute.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  
 *  2. 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.
 *  
 *  3. The end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
 *  
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
 *     without prior written permission. For written permission, please contact 
 *     Project JXTA at http://www.jxta.org.
 *  
 *  5. Products derived from this software may not be called "JXTA", nor may 
 *     "JXTA" appear in their name, without prior written permission of Sun.
 *  
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 SUN 
 *  MICROSYSTEMS OR ITS 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.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */

package net.jxta.document;


/**
 * A name value pair which is associated with some base object.
 *
 * @see net.jxta.document.Attributable
 * @see net.jxta.document.StructuredDocument
 * @see net.jxta.document.Element
 *
 **/
public class Attribute {
    
    /**
     *  The object which this attribute extends.
     **/
    private Attributable owner;
    
    /**
     *  Our name
     **/
    private String name;
    
    /**
     *  Our value
     **/
    private String value;
    
    /**
     * Constructor for a new attribute which can be added to an
     * {@link Attributable}.
     *
     * @param name Name for this attribute.
     * @param value Value for this attribute.
     **/
    public Attribute(String name, String value) {
        this(null, name, value);
    }
    
    /**
     * Constructor for a new attribute which is associated with an
     * @link Attributable} object.
     *
     * @param owner The Atrributable owner of this attribute or null.
     * @param name Name for this attribute.
     * @param value Value for this attribute.
     **/
    public Attribute(Attributable owner, String name, String value) {
        this.owner = owner;
        this.name = name;
        this.value = value;
    }
    
    /**
     * {@inheritDoc}
     **/
    @Override
    protected Object clone() {
        return this; // immutable so we can return self.
    }
    
    /**
     * {@inheritDoc}

     * The two attributes are the same if they have
     * the same owner, name and value.
     *
     * @param target Attribute to be checked with
     * @return boolean if the attributes are equal otherwise false.
     **/
    @Override
    public boolean equals(Object target) {
        if (this == target) {
            return true;
        }
        
        if (target instanceof Attribute) {
            Attribute targAttrib = (Attribute) target;
            
            boolean result = ((owner.equals(targAttrib.owner)) && name.equals(targAttrib.name) && value.equals(targAttrib.name));
            
            return result;
        } else {
            return false;
        }
    }
    
    /**
     * {@inheritDoc}
     **/
    @Override
    public int hashCode() {
        int result = name.hashCode() ^ value.hashCode();

        result ^= (null != owner) ? owner.hashCode() : 0;
        return result;
    }
    
    /**
     * {@inheritDoc}
     **/
    @Override
    public String toString() {
        return "<" + name + " = \"" + value + "\">";
    }
    
    /**
     *  Return name of this attribute
     *
     *  @return String containing the attribute's name.
     **/
    public String getName() {
        return name;
    }
    
    /**
     *  Return the {@link Attributable} which is the owner of this attribute.
     *
     *  @return Attributable object which owns this attribute.
     **/
    public Attributable getOwner() {
        return owner;
    }
    
    /**
     * Return value of this attribute
     *
     * @return String containing the attribute's value.
     **/
    public String getValue() {
        return value;
    }
}