content: /*
   * 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.
   * 
   * @author Apache Software Foundation
   * @version $Id: StringEncoderComparator.java 1080701 2011-03-11 17:52:27Z ggregory $
   */
  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.
       */
      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(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
       */
      public int compare(Object o1, Object o2) {
  
          int compareCode = 0;
  
          try {
              Comparable s1 = (Comparable) this.stringEncoder.encode(o1);
              Comparable s2 = (Comparable) this.stringEncoder.encode(o2);
              compareCode = s1.compareTo(s2);
          } catch (EncoderException ee) {
              compareCode = 0;
          }
          return compareCode;
      }
  
  }
  