001    package org.apache.myfaces.tobago.util;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one or more
005     * contributor license agreements.  See the NOTICE file distributed with
006     * this work for additional information regarding copyright ownership.
007     * The ASF licenses this file to You under the Apache License, Version 2.0
008     * (the "License"); you may not use this file except in compliance with
009     * the License.  You may obtain a copy of the License at
010     *
011     *      http://www.apache.org/licenses/LICENSE-2.0
012     *
013     * Unless required by applicable law or agreed to in writing, software
014     * distributed under the License is distributed on an "AS IS" BASIS,
015     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
016     * See the License for the specific language governing permissions and
017     * limitations under the License.
018     */
019    
020    import java.text.CollationKey;
021    import java.text.Collator;
022    import java.util.Comparator;
023    
024    
025    public abstract class ComparatorBase implements Comparator {
026    
027    
028      private Comparator comparator;
029    
030      private boolean reverse;
031    
032    
033      protected ComparatorBase() {
034      }
035    
036      protected ComparatorBase(boolean reverse, Comparator comparator) {
037        this.comparator = comparator;
038        this.reverse = reverse;
039      }
040      protected ComparatorBase(boolean reverse) {
041        this.reverse = reverse;
042      }
043    
044      protected ComparatorBase(Comparator comparator) {
045        this.comparator = comparator;
046      }
047    
048      protected int internalCompare(Object obj1, Object obj2) {
049    
050        if (obj1 == null || obj2 == null) {
051          if (obj1 == null && obj2 == null) {
052            return 0;
053          }
054          if (obj1 == null) {
055            return reverse ? 1 : -1;
056          } else {
057            return reverse ? -1 : 1;
058          }
059        }
060    
061        if (!obj1.getClass().isInstance(obj2)) {
062          throw new ClassCastException(obj1.getClass().getName() + " != "
063              + obj2.getClass().getName());
064        }
065    
066        int result;
067    
068    
069        if (comparator instanceof Collator) {
070          CollationKey collationKey1
071              = ((Collator) comparator).getCollationKey(obj1.toString());
072          CollationKey collationKey2
073              = ((Collator) comparator).getCollationKey(obj2.toString());
074          result = collationKey1.compareTo(collationKey2);
075    
076        } else if (comparator != null) {
077          result = comparator.compare(obj1, obj2);
078        } else {
079          if (obj1 instanceof String) {
080            result = ((String) obj1).compareToIgnoreCase((String) obj2);
081          } else if (obj1 instanceof Comparable) {
082            result = ((Comparable) obj1).compareTo(obj2);
083          } else {
084            result = obj1.toString().compareTo(obj2.toString());
085          }
086        }
087        return reverse ? -result : result;
088      }
089    
090      /*
091    
092      // TODO use this??
093      public boolean equals(Object o) {
094        if (this == o) {
095          return true;
096        }
097        if (o == null || getClass() != o.getClass()) {
098          return false;
099        }
100    
101        final ComparatorBase that = (ComparatorBase) o;
102    
103        return !(comparator != null ? !comparator.equals(that.comparator) : that.comparator != null);
104    
105      }
106    
107      public int hashCode() {
108        return (comparator != null ? comparator.hashCode() : 0);
109      } */
110    
111      public boolean equals(Object o) {
112        if (o == null) {
113          return false;
114        }
115        return ((ComparatorBase) o).getComparator().equals(comparator);
116      }
117    
118      public int hashCode() {
119        return (comparator != null ? comparator.hashCode() : 0);
120      }
121    
122      public Comparator getComparator() {
123        return comparator;
124      }
125    }