/*

  * Licensed to the Apache Software Foundation (ASF) under one or more

  * contributor license agreements.  See the NOTICE file distributed with

  * this work for additional information regarding copyright ownership.

  * The ASF licenses this file to You under the Apache License, Version 2.0

  * (the "License"); you may not use this file except in compliance with

  * the License.  You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.apache.commons.codec;

 import java.util.Comparator;

 /**

  * Compares Strings using a {@link StringEncoder}. This comparator is used to sort Strings by an encoding scheme such as

  * Soundex, Metaphone, etc. This class can come in handy if one need to sort Strings by an encoded form of a name such

  * as Soundex.

  *

  * <p>This class is immutable and thread-safe.</p>

  *

  * @version $Id: StringEncoderComparator.java 1468177 2013-04-15 18:35:15Z ggregory $

  */

 @SuppressWarnings("rawtypes")

 // TODO ought to implement Comparator<String> but that's not possible whilst maintaining binary compatibility.

 public class StringEncoderComparator implements Comparator {

     /**

      * Internal encoder instance.

      */

     private final StringEncoder stringEncoder;

     /**

      * Constructs a new instance.

      *

      * @deprecated Creating an instance without a {@link StringEncoder} leads to a {@link NullPointerException}. Will be

      *             removed in 2.0.

      */

     @Deprecated

     public StringEncoderComparator() {

         this.stringEncoder = null; // Trying to use this will cause things to break

     }

     /**

      * Constructs a new instance with the given algorithm.

      *

      * @param stringEncoder

      *            the StringEncoder used for comparisons.

      */

     public StringEncoderComparator(final StringEncoder stringEncoder) {

         this.stringEncoder = stringEncoder;

     }

     /**

      * Compares two strings based not on the strings themselves, but on an encoding of the two strings using the

      * StringEncoder this Comparator was created with.

      *

      * If an {@link EncoderException} is encountered, return <code>0</code>.

      *

      * @param o1

      *            the object to compare

      * @param o2

      *            the object to compare to

      * @return the Comparable.compareTo() return code or 0 if an encoding error was caught.

      * @see Comparable

      */

     @Override

     public int compare(final Object o1, final Object o2) {

         int compareCode = 0;

         try {

             @SuppressWarnings("unchecked") // May fail with CCE if encode returns something that is not Comparable

             // However this was always the case.

             final Comparable<Comparable<?>> s1 = (Comparable<Comparable<?>>) this.stringEncoder.encode(o1);

             final Comparable<?> s2 = (Comparable<?>) this.stringEncoder.encode(o2);

             compareCode = s1.compareTo(s2);

         } catch (final EncoderException ee) {

             compareCode = 0;

         }

         return compareCode;

     }

 }