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 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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 */

package com.sohu.cache.util;

import java.io.Serializable;

/**
 * <p>A convenience class to represent name-value pairs.</p>
 * @since JavaFX 2.0
 */
public class Pair<K,V> implements Serializable{

   /**
    * Key of this <code>Pair</code>.
    */
   private K key;

   /**
    * Gets the key for this pair.
    * @return key for this pair
    */
   public K getKey() { return key; }

   /**
    * Value of this this <code>Pair</code>.
    */
   private V value;

   /**
    * Gets the value for this pair.
    * @return value for this pair
    */
   public V getValue() { return value; }

   /**
    * Creates a new pair
    * @param key The key for this pair
    * @param value The value to use for this pair
    */
   public Pair(@NamedArg("key") K key, @NamedArg("value") V value) {
       this.key = key;
       this.value = value;
   }

   /**
    * <p><code>String</code> representation of this
    * <code>Pair</code>.</p>
    *
    * <p>The default name/value delimiter '=' is always used.</p>
    *
    *  @return <code>String</code> representation of this <code>Pair</code>
    */
   @Override
   public String toString() {
       return key + "=" + value;
   }

   /**
    * <p>Generate a hash code for this <code>Pair</code>.</p>
    *
    * <p>The hash code is calculated using both the name and
    * the value of the <code>Pair</code>.</p>
    *
    * @return hash code for this <code>Pair</code>
    */
   @Override
   public int hashCode() {
       // name's hashCode is multiplied by an arbitrary prime number (13)
       // in order to make sure there is a difference in the hashCode between
       // these two parameters:
       //  name: a  value: aa
       //  name: aa value: a
       return key.hashCode() * 13 + (value == null ? 0 : value.hashCode());
   }

    /**
     * <p>Test this <code>Pair</code> for equality with another
     * <code>Object</code>.</p>
     *
     * <p>If the <code>Object</code> to be tested is not a
     * <code>Pair</code> or is <code>null</code>, then this method
     * returns <code>false</code>.</p>
     *
     * <p>Two <code>Pair</code>s are considered equal if and only if
     * both the names and values are equal.</p>
     *
     * @param o the <code>Object</code> to test for
     * equality with this <code>Pair</code>
     * @return <code>true</code> if the given <code>Object</code> is
     * equal to this <code>Pair</code> else <code>false</code>
     */
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o instanceof Pair) {
            Pair pair = (Pair) o;
            if (key != null ? !key.equals(pair.key) : pair.key != null) return false;
            if (value != null ? !value.equals(pair.value) : pair.value != null) return false;
            return true;
        }
        return false;
    }
}

