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