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      1 /*
      2  * Copyright (C) 2009 The Guava Authors
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  * http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.google.common.collect;
     18 
     19 import com.google.common.annotations.GwtCompatible;
     20 
     21 import java.io.Serializable;
     22 import java.util.Arrays;
     23 
     24 /**
     25  * A class that implements {@code Comparable} without generics, such as those
     26  * found in libraries that support Java 1.4 and before. Our library needs to
     27  * do the bare minimum to accommodate such types, though their use may still
     28  * require an explicit type parameter and/or warning suppression.
     29  *
     30  * @author Kevin Bourrillion
     31  */
     32 @GwtCompatible
     33 class LegacyComparable implements Comparable, Serializable {
     34   static final LegacyComparable X = new LegacyComparable("x");
     35   static final LegacyComparable Y = new LegacyComparable("y");
     36   static final LegacyComparable Z = new LegacyComparable("z");
     37 
     38   static final Iterable<LegacyComparable> VALUES_FORWARD
     39       = Arrays.asList(X, Y, Z);
     40   static final Iterable<LegacyComparable> VALUES_BACKWARD
     41       = Arrays.asList(Z, Y, X);
     42 
     43   private final String value;
     44 
     45   LegacyComparable(String value) {
     46     this.value = value;
     47   }
     48 
     49   @Override
     50   public int compareTo(Object object) {
     51     // This method is spec'd to throw CCE if object is of the wrong type
     52     LegacyComparable that = (LegacyComparable) object;
     53     return this.value.compareTo(that.value);
     54   }
     55 
     56   @Override public boolean equals(Object object) {
     57     if (object instanceof LegacyComparable) {
     58       LegacyComparable that = (LegacyComparable) object;
     59       return this.value.equals(that.value);
     60     }
     61     return false;
     62   }
     63 
     64   @Override public int hashCode() {
     65     return value.hashCode();
     66   }
     67 
     68   private static final long serialVersionUID = 0;
     69 }
     70