/*

  Copyright 2004-2008 Paul R. Holser, Jr.  All rights reserved.

  Licensed under the Academic Free License version 3.0

  */

 package jaggregate;

 /**

  * A simple string-to-string pair, created by parsing a string of the form

  * {@code "key=value"}.

  *

  * @author <a href="mailto:pholser@alumni.rice.edu">Paul Holser</a>

  * @version $Id: KeyValuePair.java,v 1.2 2008/03/26 18:00:33 pholser Exp $

  */

 public final class KeyValuePair extends Pair<String, String> {

     private static final long serialVersionUID = -1L;

     private static final String ZERO_LENGTH = "";

     private KeyValuePair( String key, String value ) {

         super( key, value );

     }

     /**

      * Creates a string-to-string pair by parsing a string of the form {@code

      * "key=value"}.

      *

      * @param aString the string representation of the pair

      * @return the pair

      */

     public static KeyValuePair parse( String aString ) {

         int indexOfEqualsSign = aString.indexOf( "=" );

         if ( indexOfEqualsSign == -1 )

             return new KeyValuePair( aString, ZERO_LENGTH );

         String parsedKey = aString.substring( 0, indexOfEqualsSign );

         String parsedValue;

         if ( indexOfEqualsSign == aString.length() - 1 )

             parsedValue = ZERO_LENGTH;

         else

             parsedValue = aString.substring( indexOfEqualsSign + 1 );

         return new KeyValuePair( parsedKey, parsedValue );

     }

 }